Scott Southworth David K. Brezinski Avery Ala Drake, Jr William C. Burton Randall C. Orndorff Albert J. Froelich James E. Reddy Danielle Denenny David L. Daniels E. Allen Crider Jr Benjamin R. Weinmann 20250430 vector digital data Scientific Investigations Map 2889 Reston, Virginia U.S. Geological Survey Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. pamphlet, https://pubs.usgs.gov/sim/2889/ https://doi.org/10.5066/P13REKRW The database for the geologic map of the Frederick 30 x 60 quadrangle covers the distinct geologic provinces and sections of the central Appalachian region that are defined by unique bedrock and resulting landforms. From west to east, the provinces include the Great Valley section of the Valley and Ridge province, the Blue Ridge province, and the Piedmont province; in the extreme southeastern corner, a small part of the Coastal Plain province is present. The Piedmont province is divided into several sections; from west to east, they are the Frederick Valley synclinorium, the Culpeper and Gettysburg basins, the Sugarloaf Mountain anticlinorium, the Westminster terrane, and the Potomac terrane. The Blue Ridge province contains Mesoproterozoic (1 billion years old, or 1 Ga) paragneiss and granitic gneisses that are intruded by a swarm of Neoproterozoic (570 million years old, or 570 Ma) metadiabase and metarhyolite dikes. Unconformably overlying the gneisses are Neoproterozoic metasedimentary rocks and metavolcanic rocks associated with the dikes. The Mesoproterozoic gneisses were deformed and metamorphosed during the Grenville orogeny. Subsequently, the Neoproterozoic metasedimentary and metavolcanic rocks accumulated during a continental rifting event (Rankin, 1976). Clastic metasedimentary rocks of the newly formed continental margin were deposited paraconformably upon the Neoproterozoic rocks. To the east, Neoproterozoic and early Paleozoic metasedimentary and metavolcanic rocks were deposited on the margin of the rifted continent. These rocks underlie the Sugarloaf Mountain anticlinorium and Westminster and Potomac terranes. As the rifted continental margin stabilized and became a passive margin during the early Paleozoic, carbonate rocks were deposited on the broad continental shelf. Those carbonate rocks are now exposed in the Great Valley section and the Frederick Valley synclinorium. The early Paleozoic carbonate platform became unstable in response to the Ordovician Taconian orogeny. Deformation associated with this tectonic event is recorded in rocks of the Piedmont province to the east. These rocks, which are now part of the Potomac terrane, were thrust westward onto rocks of the Westminster terrane; next, rocks of the Westminster terrane were thrust onto rocks now exposed in the Sugarloaf Mountain anticlinorium and Frederick Valley synclinorium (Drake and others, 1989; Southworth, 1996). The early Paleozoic sea eventually closed up and disappeared during the continental collision of tectonic plates during the late Paleozoic Alleghanian orogeny. The Alleghanian orogeny transported all of the rocks within the map area westward along the North Mountain thrust fault, which is exposed immediately northwest of the quadrangle. The Alleghanian orogeny produced numerous thrust faults and folds in the rock and regional-scale folds that help define the geologic provinces. The Massanutten synclinorium underlies the Great Valley section, the Blue Ridge-South Mountain anticlinorium underlies the Blue Ridge province, and the Frederick Valley synclinorium and Sugarloaf Mountain anticlinorium underlie the western Piedmont province. Tens of millions of years after the Alleghanian orogeny, early Mesozoic continental rifting formed the Culpeper and Gettysburg basins, which once were connected to form a large down-faulted basin filled with sediments that eroded from the adjacent Blue Ridge and Piedmont highlands. Continued rifting resulted in igneous intrusions and extrusive volcanic rock at about 200 Ma, and eventually led to the opening of the Atlantic Ocean to the east. Sediments eroded from the Appalachian highlands were deposited by river systems and transgressing seas and now form the Coastal Plain province. The geologic map of the Frederick 30 x 60 quadrangle is intended to serve as a foundation for applying geologic information to problems involving land use decisions, groundwater availability and quality, earth resources such as natural aggregate for construction, assessment of natural hazards (earthquakes), and engineering and environmental studies for waste disposal sites and construction projects. FrederickMDVAWVSIM2889.gdb is a composite geodataset that conforms to GeMS (Geologic Map Schema)--a standard format for the digital publication of geologic maps", available at http://ngmdb.usgs.gov/Info/standards/GeMS/. Metadata records associated with each element within the geodataset contain more detailed descriptions of their purposes, constituent entities, and attributes). An OPEN shapefile versions of the dataset is also available. It consists of shapefiles, DBF files, and delimited text files and retains all information in the native geodatabase, but some programming will likely be necessary to assemble these components into usable formats. These metadata were prepared with the aid of script GeMS_FGDCMetadata.py, version of 2/27/24. 20250401 publication date Complete Unknown -78.0214 -76.9858 39.5215 38.9786 ISO 19115 Topic Category geoscientificInformation Geologic Names Martinsburg Formation Chambersburg Formation St. Paul Group New Market Limestone Row Park Limestone Beekmantown Group Pinesburg Station Dolomite Rockdale Run Formation Stonehenge Limestone Stoufferstown Member Conocheague Limestone Big Spring Station Member Elbrook Limestone Waynesboro Formation Chewsville Member Cavetown Member Red Run Member Tomstown Formation Dargan Member Benevola Member Fort Duncan Member Bolivar Heights Member Chilhowee Group Antietam Formation Harpers Formation Weverton Formation Owens Creek Member Maryland Heights Member Buzzard Knob Member Loudoun Formation Catoctin Formation Swift Run Formation Fauquier Group Carter Run Formation Swains Mountain Formation Cobbler Mountain Alkali Feldspar Quartz Syenite Robertson River Igneous Suite Meriden Group Sander Basalt Turkey Run Formation Hickory Grove Basalt Midland Formation Chatham Group Mount Zion Church Basalt Catharpin Creek Formation Goose Creek Member Bull Run Formation Groveton Member Balls Bluff Member Leesburg Member Manassas Sandstone Poolesville Member Tuscarora Creek Member Reston Member Grove Formation Frederick Formation Lime Kiln Member Adamstown Member Rocky Springs Station Member Cash Smith Formation Araby Formation Urbana Formation Sugarloaf Mountain Quartzite Wakefield Marble Sams Creek Formation Ijamsville Phyllite Marburg Formation Prettyboy Schist Guilford Granite Norbeck Intrusive Suite Kensington Tonalite Georgetown Intrusive Suite Dalecarlia Intrusive Suite Bear Island Granodiorite Sykesville Formation Laurel Formation Oella Formation Loch Raven Schist Northwest Branch Formation Mather Gorge Formation Soldiers Delight Ultramafite Potomac Formation Lithologic classification of geologic map units unconsolidated material alluvium alluvial terrace silt sand gravel lake or marine sediment mass wasting material colluvium sedimentary rock clastic rock mudstone shale black shale siltstone sandstone conglomerate sedimentary breccia melange carbonate rock limestone dolostone mixed carbonate/clastic rock mixed volcanic/clastic rock chemical sedimentary rock felsic volcanic rock rhyolite mafic volcanic rock basalt ultramafitite plutonic rock aplite pegmatite granitoid quartz diorite diorite diabase granite metaluminous granite granodiorite tonalite trondhjemite quartz syenite syenite monzonite gabbroid quartz gabbro norite ultramafic intrusive rock pyroxenite metamorphic rock hornfels calc-silicate rock serpentinite metasedimentary rock slate quartzite metaconglomerate marble metavolcanic rock felsic metavolcanic rock metarhyolite mafic metavolcanic rock metabasalt phyllite schist granofels gneiss felsic gneiss granitic gneiss biotite gneiss orthogneiss paragneiss migmatite amphibolite tectonite phyllonite mylonite USGS Thesaurus maps and atlases geologic maps earth sciences geology economic geology geochronology sedimentology stratigraphy structural geology geologic processes sinkhole formation metamorphism (geological) alteration sedimentation tectonic processes deformation (geologic) folding (geologic) fracture (geologic) faulting (geologic) geologic history earth history geologic structure foliation (geologic) lineation (geologic) karst rocks and deposits igneous rocks volcanic rocks plutonic rocks metamorphic rocks sedimentary rocks unconsolidated deposits bedrock geologic units geologic contacts unconformities surficial geologic units geologic time periods Phanerozoic Cenozoic Quaternary Holocene Pleistocene Tertiary Mesozoic Cretaceous Jurassic Triassic Paleozoic Cambrian Devonian Ordovician Silurian Precambrian Proterozoic Neoproterozoic Mesoproterozoic USGS Metadata Identifier USGS:679107ddd34ea6a4002bf792 Geographic Names Maryland Virginia West Virginia Montgomery (county) Howard (county) Clarke (county) Fauquier (county) Frederick (county) Carroll (county) Washington (county) Loudoun (county) Fairfax (county) Jefferson (county) Berkeley (county) Westminister New Windsor Union Bridge Woodsboro Catoctin Furnace Finksburg Myersville Winfield Funkstown Libertytown Williamsport Walkersville Hedgesville Frederick Big Pool Sykesville Middletown Woodbine Keedysville Damascus Shepherdstown Urbana Martinsburg Buckeystown Tablers Station Clarksville Point of Rocks Sandy Spring Harpers Ferry Gaithersburg Charles Town Germantown Middleway Poolesville Inwood Beltsville Waterford Kensington Purcellville Rockville Round Hill Seneca Berryville Sterling Stephenson Washington East Leesburg Washington West Lincoln Falls Church Bluemont Vienna Ashby Gap Herndon Boyce Arcola Middleburg Rectortown Upperville Linden None. Acknowledgment of the U.S. Geological Survey would be appreciated in products derived from these data. None. Acknowledgment of the U.S. Geological Survey would be appreciated in products derived from these data. Although software enables the user to display images at various scales, map data in this report should not be used at scales greater than 1:100,000. U.S. Geological Survey, Northeast Region Ernest A Crider Geologist mailing

Mail Stop 926A, 12201 Sunrise Valley Dr

Reston VA 20192 US 703-648-6906 703-648-6953 ecrider@usgs.gov Funding for this report was provided by the National Cooperative Geologic Mapping Program (NCGMP) from 1975 to 2025. Version 6.2 (Build 9200); Esri ArcGIS 10.6.0.8321; ESRI ArcPro 3.4.0 Geologic contacts and information were garnered from 1:24,000-scale mapping of geologic material based on observation from fieldwork, previously published geologic maps, and unpublished geologic data in the region. The geologic information might change if additional outcrops are discovered or exposed as the natural land changes, or as the result of development, or advances in scientific research are made. The features in the database are not based on legal parcels or definitions. Users of this data should pay close attention to the DataSources table within the database. Sources of material for the map and database are documented in this table but may not be in the metadata. Confidence that a feature exists and confidence that a feature is correctly identified are described in per-feature attributes ExistenceConfidence and IdentityConfidence. Geologic contacts and information were garnered from 1:24,000-scale mapping of bedrock material based on observation from and geologic fieldwork in the region. The geologic information might change if additional outcrops are discovered or exposed as the natural land changes or as the result of development. The features in the database are not based on legal parcels or definitions. Topology tests were performed to ensure the integrity of the data. These tests checked for polygon overlaps and gaps and line pseudos, dangles, and intersections. Additional tests were conducted to ensure that line work from geologic contacts match polygon boundaries where necessary. Database verifies as level 2 compliant under the "GeMS" schema; because the water polygon in the MapUnitOverlayPolys feature class does not have a definition in the DescriptionofMapUnits table. Dataset is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details. Data were delineated on classic U.S. Geological Survey (USGS) 7.5-minute topographic maps at 1:100,000 scale. Therefore, the horizontal accuracy is assumed to be within National Map Accuracy Standards, with a horizontal accuracy of 45.6 feet at the 95% confidence level. In addition, the horizontal accuracy standard requires that the positions of 90 percent of all points tested must be accurate within 1/50th of an inch (0.05 centimeters) on the map. For more information see U.S. Geological Survey Fact Sheet 171-99. Estimated accuracy of horizontal location is given on a per-feature basis by attribute LocationConfidenceMeters. Values are expected to be correct within a factor of 2. A LocationConfidenceMeters value of -9 or -9999 indicates that no value has been assigned. The data were delineated on classic U.S. Geological Survey (USGS) 7.5-minute topographic maps at 1:100,000 scale. Therefore, the vertical accuracy is assumed to be within National Map Accuracy Standards, with a vertical accuracy of 11.9 feet at the 95% confidence level. In addition, the vertical accuracy standard requires that the elevation of 90 percent of all points tested must be correct within half of the contour interval. For more information see U.S. Geological Survey Fact Sheet 171-99. Federal Geographic Data Committee (FGDC) U.S. Geological Survey (USGS) 2006 publication Reston, VA U.S. Geological Survey Federal Geographic Data Committee [prepared for the Federal Geographic Data Committee by the U.S. Geological Survey], 2006, FGDC Digital Cartographic Standard for Geologic Map Symbolization: Reston, Va., Federal Geographic Data Committee Document Number FGDC-STD-013-2006, 290 p., 2 plates. https://ngmdb.usgs.gov/fgdc_gds/geolsymstd.php Digital and/or Hardcopy 2006 publication date FGDC This citation was used in the production of this database, either in the description of map units, or the production of geologic polygons, or the additional supporting structural and cartographic information. U.S. Geological Survey (USGS) Science Publishing Network (SPN) 2015 publication U.S. Geological Survey Science Publishing Network, MapStyleGuide_DMU_print_1sht_v1-1_01-15.pdf. Digital and/or Hardcopy 2015 publication date USGS This citation was used in the production of this database, either in the description of map units, or the production of geologic polygons, or the additional supporting structural and cartographic information. National Cooperative Geologic Mapping Program (NCGMP) U.S. Geological Survey (USGS) 2020 publication Reston, VA U.S. Geological Survey U.S. Geological Survey National Cooperative Geologic Mapping Program, 2020, GeMS (Geologic Map Schema)—A standard format for the digital publication of geologic maps: U.S. Geological Survey Techniques and Methods, book 11, chap. B10, 74 p. https://doi.org/10.3133/tm11B10 Digital and/or Hardcopy 2020 publication date GeMS This citation was used in the production of this database, either in the description of map units, or the production of geologic polygons, or the additional supporting structural and cartographic information. K.K.E. Neuendorf J.P. Mehl, Jr. J.A. Jackson 2011 5 publication Alexandria, VA American Geosciences Institute Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2011, Glossary of geology (5th ed., revised): Alexandria, Va., American Geosciences Institute, 783 p. https://glossary.americangeosciences.org/ Digital and/or Hardcopy 2011 publication date AGI This citation was used in the production of this database, either in the description of map units, or the production of geologic polygons, or the additional supporting structural and cartographic information. C.S. Southworth D.K. Brezinski A.A. Drake, Jr W.C. Burton R.C. Orndorff A.J. Froelich J.E. Reddy D. Denenny D.L. Daniels 2007 publication Scientific Investigations Map 2889 Reston, VA U.S. Geological Survey Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. https://ngmdb.usgs.gov/Prodesc/proddesc_83523.htm 100000 Digital and/or Hardcopy 2007 publication date DASFRED100K003 This citation was used in the production of this database, either in the description of map units, or the production of geologic polygons, or the additional supporting structural and cartographic information. J.N. Aleinikoff R.E. Zartman M.Walter D.W. Rankin P.T. Lyttle W.C. Burton 1995 publication American Journal of Science v. 295, no. 4 N/A American Journal of Science Aleinikoff, J.N., Zartman, R.E., Walter, Marianne, Rankin, D.W., Lyttle, P.T., and Burton, W.C., 1995, U-Pb ages of metarhyolites of the Catoctin and Mount Rogers Formations, central and southern Appalachians; Evidence for two pulses of Iapetan rifting: American Journal of Science, v. 295, no. 4, p. 428–454. https://doi.org/10.2475/ajs.295.4.428 Digital and/or Hardcopy 1995 publication date DASFRED100K004 This citation was used in the production of this database, either in the description of map units, or the production of geologic polygons, or the additional supporting structural and cartographic information. J.N Aleinikoff W.C Burton P.T Lyttle A.E Nelson C.S. Southworth 2000 publication Precambrian Research v. 99, nos. 1-2 N/A Elsevier BV Aleinikoff, J.N., Burton, W.C., Lyttle, P.T., Nelson, A.E., and Southworth, C.S., 2000, U-Pb geochronology of zircon and monazite from Mesoproterozoic granitic gneisses of the northern Blue Ridge, Virginia and Maryland: Precambrian Research, v. 99, nos. 1–2, p. 113–146. https://doi.org/10.1016/S0301-9268(99)00056-X Digital and/or Hardcopy 2000 publication date DASFRED100K005 This citation was used in the production of this database, either in the description of map units, or the production of geologic polygons, or the additional supporting structural and cartographic information. D.K. Brezinski 1996 publication Special Publication 3 Baltimore, MD Maryland Geological Survey Brezinski, D.K., 1996, Stratigraphy of the Elbrook Formation (Middle to Upper Cambrian) in Maryland and adjacent States, in Brezinski, D.K., and J.P. Reger, eds., Studies in Maryland geology: Maryland Geological Survey Special Publication 3, p. 165–186. http://www.mgs.md.gov/output/reports/SP/SP_3.pdf Digital and/or Hardcopy 1996 publication date DASFRED100K012 This citation was used in the production of this database, either in the description of map units, or the production of geologic polygons, or the additional supporting structural and cartographic information. D.K. Brezinski 2004 publication Baltimore, MD Maryland Geological Survey Brezinski, D.K., 2004a, Geology of the Frederick quadrangle, Frederick County, Maryland: Baltimore, Maryland Geological Survey Digital Quadrangle Geologic Map, version FREDEGEO2004.1, scale 1:24,000, 1 CD-ROM. 24000 Digital and/or Hardcopy 2004 publication date DASFRED100K013 This citation was used in the production of this database, either in the description of map units, or the production of geologic polygons, or the additional supporting structural and cartographic information. D.K. Brezinski 2004 publication Baltimore, MD Maryland Geological Survey Brezinski, D.K., 2004b, Geology of the Maryland portion of the Point of Rocks quadrangle, Frederick County, Maryland: Baltimore, Maryland Geological Survey Digital Quadrangle Geologic Map, version PTOFRGEO2004.1, scale 1:24,000, 1 CD-ROM. 24000 Digital and/or Hardcopy 2004 publication date DASFRED100K014 This citation was used in the production of this database, either in the description of map units, or the production of geologic polygons, or the additional supporting structural and cartographic information. D.K. Brezinski J.L. Fauth 2005 publication Baltimore, MD Maryland Geological Survey Brezinski, D.K., and Fauth, J.L., 2005, Geologic map of the Middletown quadrangle, Frederick and Washington Counties, Maryland: Baltimore, Maryland Geological Survey Digital Quadrangle Geologic Map, version MIDDLGEO2005.1, scale 1:24,000, 1 CD-ROM. 24000 Digital and/or Hardcopy 2005 publication date DASFRED100K015 This citation was used in the production of this database, either in the description of map units, or the production of geologic polygons, or the additional supporting structural and cartographic information. D.K. Brezinski C.S. Southworth J. Edwards, Jr. 2004 publication Baltimore, MD Maryland Geological Survey Brezinski, D.K., Southworth, Scott, and Edwards, Jonathan, Jr., 2004, Geologic map of the Walkersville quadrangle: Baltimore, Maryland Geological Survey, scale 1:24,000. 24000 Digital and/or Hardcopy 2004 publication date DASFRED100K017 This citation was used in the production of this database, either in the description of map units, or the production of geologic polygons, or the additional supporting structural and cartographic information. W.C. Burton A.J. Froelich J.S. Pomeroy K.Y. Lee 1995 publication Bulletin 2095 Reston, VA U.S. Geological Survey Burton, W.C., Froelich, A.J., Pomeroy, J.S., and Lee, K.Y., 1995, Geology of the Waterford quadrangle, Virginia and Maryland, and the Virginia part of the Point of Rocks quadrangle: U.S. Geological Survey Bulletin 2095, 30 p., 1 pl. in pocket, scale 1:24,000. https://ngmdb.usgs.gov/Prodesc/proddesc_22396.htm 24000 Digital and/or Hardcopy 1995 publication date DASFRED100K019 This citation was used in the production of this database, either in the description of map units, or the production of geologic polygons, or the additional supporting structural and cartographic information. S.L. Dean B.R. Kulander P. Lessing 1987 publication Dean, S.L., Kulander, B.R., and Lessing, Peter, 1987, Geology of the Hedgesville, Keedysville, Martinsburg, Shepherdstown, and Williamsport quadrangles, Berkeley and Jefferson Counties, West Virginia: West Virginia Geological and Economic Survey Map WV–31, scale 1:24,000. 24000 Digital and/or Hardcopy 1987 publication date DASFRED100K026 This citation was used in the production of this database, either in the description of map units, or the production of geologic polygons, or the additional supporting structural and cartographic information. S.L. Dean P. Lessing B.R. Kulander 1990 publication Dean, S.L., Lessing, Peter, and Kulander, B.R., 1990, Geology of the Berryville, Charles Town, Harpers Ferry, Middleway, and Round Hill quadrangles, Berkeley and Jefferson Counties, West Virginia: West Virginia Geological and Economic Survey Map WV–35, scale 1:24,000. 24000 Digital and/or Hardcopy 1990 publication date DASFRED100K027 This citation was used in the production of this database, either in the description of map units, or the production of geologic polygons, or the additional supporting structural and cartographic information. A.A. Drake, Jr. 1998 publication Geologic Quadrangle Map 1774 Reston, VA U.S. Geological Survey Drake, A.A., Jr., 1998, Geologic map of the Kensington quadrangle, Montgomery County, Maryland: U.S. Geological Survey Geologic Quadrangle Map GQ–1774, scale 1:24,000. https://doi.org/10.3133/gq1774 24000 Digital and/or Hardcopy 1998 publication date DASFRED100K031 This citation was used in the production of this database, either in the description of map units, or the production of geologic polygons, or the additional supporting structural and cartographic information. A.A. Drake, Jr. A.J. Froelich 1997 publication Geologic Quadrangle Map 1734 Reston, VA U.S. Geological Survey Drake, A.A., Jr., and Froelich, A.J., 1997, Geologic map of the Falls Church quadrangle, Fairfax and Arlington Counties, and the city of Falls Church, Virginia and Montgomery County, Maryland: U.S. Geological Survey Geologic Quadrangle Map GQ–1734, scale 1:24,000. https://doi.org/10.3133/gq1734 24000 Digital and/or Hardcopy 1997 publication date DASFRED100K033 This citation was used in the production of this database, either in the description of map units, or the production of geologic polygons, or the additional supporting structural and cartographic information. A.A. Drake, Jr. C.S. Southworth K.Y. Lee 1999 publication Geologic Quadrangle Map 1802 Reston, VA U.S. Geological Survey Drake, A.A., Jr., Southworth, Scott, and Lee, K.Y., 1999, Geologic map of the Seneca quadrangle, Montgomery County, Maryland, and Fairfax and Loudoun Counties, Virginia: U.S. Geological Survey Geologic Quadrangle Map GQ–1802, scale 1:24,000. https://doi.org/10.3133/gq1802 24000 Digital and/or Hardcopy 1999 publication date DASFRED100K035 This citation was used in the production of this database, either in the description of map units, or the production of geologic polygons, or the additional supporting structural and cartographic information. R.S. Edmundson W.E. Nunan 1973 publication Report of Investigations 34 Charlottesville, VA Virginia Division of Mineral Resource Edmundson, R.S., and Nunan, W.E., 1973, Geology of the Berryville, Stephenson, and Boyce quadrangles, Virginia: Virginia Division of Mineral Resources Report of Investigations 34, 112 p., 3 pls. in pocket, scale 1:24,000. 24000 Digital and/or Hardcopy 1973 publication date DASFRED100K036 This citation was used in the production of this database, either in the description of map units, or the production of geologic polygons, or the additional supporting structural and cartographic information. A.H. Fleming A.A. Drake, Jr. L. McCartan 1994 publication Geologic Quadrangle Map 1748 Reston, VA U.S. Geological Survey Fleming, A.H., Drake, A.A., Jr., and McCartan, Lucy, 1994, Geologic map of the Washington West quadrangle, District of Columbia, Montgomery and Prince Georges Counties, Maryland, and Arlington and Fairfax Counties, Virginia: U.S. Geological Survey Geologic Quadrangle Map GQ– 1748, scale 1:24,000. https://doi.org/10.3133/gq1748 24000 Digital and/or Hardcopy 1994 publication date DASFRED100K047 This citation was used in the production of this database, either in the description of map units, or the production of geologic polygons, or the additional supporting structural and cartographic information. T.M. Gathright, II P.G. Nystrom, Jr. 1974 publication Report of Investigations 36 Charlottesville, VA Virginia Division of Mineral Resources Gathright, T.M., II, and Nystrom, P.G., Jr., 1974, Geology of the Ashby Gap quadrangle, Virginia: Virginia Division of Mineral Resources Report of Investigations 36, 55 p. 24000 Digital and/or Hardcopy 1974 publication date DASFRED100K051 This citation was used in the production of this database, either in the description of map units, or the production of geologic polygons, or the additional supporting structural and cartographic information. L.C.S. Gunderson G.M. Reimer C.R. Wiggs C.A. Rice 1988 publication Miscellaneous Field Studies Map 2043 Reston, VA U.S. Geological Survey Gunderson, L.C.S., Reimer, G.M., Wiggs, C.R., and Rice, C.A., 1988, Map showing radon potential of rocks and soils in Montgomery County, Maryland: U.S. Geological Survey Miscellaneous Field Studies Map MF–2043, scale 1:62,500. 62500 Digital and/or Hardcopy 1988 publication date DASFRED100K052 This citation was used in the production of this database, either in the description of map units, or the production of geologic polygons, or the additional supporting structural and cartographic information. C.A. Hopson 1964 publication Baltimore, MD Maryland Geological Survey Hopson, C.A., 1964, The crystalline rocks of Howard and Montgomery Counties, Md., in The geology of Howard and Montgomery Counties: Baltimore, Maryland Geological Survey, p. 27–215. Digital and/or Hardcopy 1964 publication date DASFRED100K055 This citation was used in the production of this database, either in the description of map units, or the production of geologic polygons, or the additional supporting structural and cartographic information. R.C. McDowell D.J. Milton 1992 publication Geologic Quadrangle Map 1702 Reston, VA U.S. Geological Survey McDowell, R.C., and Milton, D.J., 1992, Geologic map of the Round Hill quadrangle, Virginia and West Virginia: U.S. Geological Survey Geologic Quadrangle Map GQ–1702, scale 1:24,000. https://ngmdb.usgs.gov/Prodesc/proddesc_1209.htm 24000 Digital and/or Hardcopy 1992 publication date DASFRED100K080 This citation was used in the production of this database, either in the description of map units, or the production of geologic polygons, or the additional supporting structural and cartographic information. C.S. Southworth 1994 publication Geologic Quadrangle Map 1739 Reston, VA U.S. Geological Survey Southworth, Scott, 1994, Geologic map of the Bluemont quadrangle, Loudoun and Clarke Counties, Virginia: U.S. Geological Survey Geologic Quadrangle Map GQ–1739, scale 1:24,000. https://doi.org/10.3133/gq1739 24000 Digital and/or Hardcopy 1994 publication date DASFRED100K096 This citation was used in the production of this database, either in the description of map units, or the production of geologic polygons, or the additional supporting structural and cartographic information. C.S. Southworth 1995 publication Geologic Quandrangle Map 1755 Reston, VA U.S. Geological Survey Southworth, Scott, 1995, Geologic map of the Purcellville quadrangle, Loudoun County, Virginia: U.S. Geological Survey Geologic Quadrangle Map GQ–1755, scale 1:24,000. https://doi.org/10.3133/gq1755 24000 Digital and/or Hardcopy 1995 publication date DASFRED100K097 This citation was used in the production of this database, either in the description of map units, or the production of geologic polygons, or the additional supporting structural and cartographic information. C.S. Southworth 1998 publication Geologic Quandrangle Map 1761 Reston, VA U.S. Geological Survey Southworth, Scott, 1998, Geologic map of the Poolesville quadrangle, Frederick and Montgomery Counties, Maryland and Loudoun County, Virginia: U.S. Geological Survey Geologic Quadrangle Map GQ–1761, 12 p. and 1:24,000- scale map. https://doi.org/10.3133/gq1761 24000 Digital and/or Hardcopy 1998 publication date DASFRED100K099 This citation was used in the production of this database, either in the description of map units, or the production of geologic polygons, or the additional supporting structural and cartographic information. C.S. Southworth 1999 publication Geologic Quadrangle Map 1768 Reston, VA U.S. Geological Survey Southworth, Scott, 1999, Geologic map of the Urbana quadrangle, Frederick and Montgomery Counties, Maryland: U.S. Geological Survey Geologic Quadrangle GQ–1768, scale 1:24,000. https://doi.org/10.3133/gq1768 Digital and/or Hardcopy 1999 publication date DASFRED100K100 This citation was used in the production of this database, either in the description of map units, or the production of geologic polygons, or the additional supporting structural and cartographic information. C.S. Southworth D.K. Brezinski 1996 publication Bulletin 2123 Reston, VA U.S. Geological Survey Southworth, Scott, and Brezinski, D.K., 1996b, Geology of the Harpers Ferry quadrangle, Virginia, Maryland, and West Virginia: U.S. Geological Survey Bulletin 2123, 33 p., 1 pl. in pocket, scale 1:24,000. https://doi.org/10.3133/b2123 24000 Digital and/or Hardcopy 1996 publication date DASFRED100K102 This citation was used in the production of this database, either in the description of map units, or the production of geologic polygons, or the additional supporting structural and cartographic information. C.S. Southworth D.K. Brezinski 2003 publication Geologic Quadrangle Map 1800 Reston, VA U.S. Geological Survey Southworth, Scott, and Brezinski, D.K., 2003, Geologic map of the Buckeystown quadrangle, Frederick and Montgomery Counties, Maryland, and Loudoun County, Virginia: U.S. Geological Survey Geologic Quadrangle Map GQ–1800, scale 1:24,000. https://doi.org/10.3133/gq1800 24000 Digital and/or Hardcopy 2003 publication date DASFRED100K103 This citation was used in the production of this database, either in the description of map units, or the production of geologic polygons, or the additional supporting structural and cartographic information. The original raster of the Frederick map was georeferenced and brought into ArcMap 10.8. Lines for bedrock and surficial contacts were digitized in ArcMap then smoothed and generalized, and loaded into the ContactsAndFaults feature class. Topology checks were performed on the line work. The ContactsAndFaults were used to create the polygons for the MapUnitPolys and the polygons were attributed from the raster map. The same process was used for the surficial unit contacts and polygons. OrientationPoints were extracted from the raster map using the Geologic Map Data Extractor (GMDE) program. Points from the exported speadsheet generated by GMDE were imported to ArcMap and attributed (symbolized) to match the original raster. Additional smoothing of line work and the completion of ExistenceConfidence, IdentityConfidence, and LocationConfidenceMeters was completed in late 2024; using previously published 24,000-scale geologic maps that pre and post-date the original 100,000-scale geologic map. Minor changes were made to geologic map unit colors at this time. Substantial changes were not made with maps that substantially post date the original publication. Updates were made to the database to help match it with the Washington West geologic map database to the south. Changes and comments were left in the notes field to denote changes or updates from the original publication in almost all feature classes. 20250401 U.S. Geological Survey, Northeast Region Ernest A Crider Geologist mailing

Mail Stop 926A, 12201 Sunrise Valley Dr

Reston VA 20192 US 703-648-6953 ecrider@usgs.gov Vector G-polygon Universal Transverse Mercator 18 0.9996 -75.0 0.0 500000.0 0.0 coordinate pair 0.6096 0.6096 meters North_American_Datum_1983 GRS 1980 6378137.0 298.257222101 DescriptionOfMapUnits Non-spatial table that captures content of the Description of Map Units (or equivalent List of Map Units and associated pamphlet text) included in a traditional paper geologic map. Has an internal hierarchy expressed by attribute HierarchyKey GeMS OBJECTID Internal feature number ESRI Unrepresentable domain MapUnit Short plain-text identifier of the map unit. Foreign key to DescriptionOfMapUnits table. GeMS Csql Lower member of the Sugarloaf Mountain Quartzite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ccwm Maryland Heights Member of the Weverton Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ccw Undivided rocks of the Weverton Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. QTt High level terrace deposit This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Jms Sander Basalt This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Obs Upper part of the Stonehenge Limestone This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cfl Lime Kiln Member of the Frederick Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Zrc Cobbler Mountain Alkali Feldspar Quartz Syenite of the Robertson River Igneous Suite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cclc Conglomerate of the Loudoun Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ylg Layered granitic gneiss This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Csqu Upper member of the Sugarloaf Mountain Quartzite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cfa Adamstown Member of the Frederick Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZsc Calcareous metasandstone of the Sams Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Qt Low level terrace deposit This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZl Loch Raven Schist This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ctd Dargan Member of the Tomstown Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cu Urbana Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cfrs Shale of the Rocky Springs Station Member of the Frederick Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Jmt Turkey Run Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Zfsm Metamudstone of the Swains Mountain Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ong Quartz gabbro of the Norbeck Intrusive Suite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZpq Quartzite of the Prettyboy Schist This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cs Sykesville Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZpb Metabasalt of the Prettyboy Schist This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Jmhs Sandstone and siltstone of the Hickory Grove Basalt This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Jmmc Conglomerate of the Midland Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ql Lag gravel This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ct Tomstown Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cum Marble of the Urbana Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ob Bear Island Granodiorite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Yc Charnockitic granite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Om Martinsburg Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ok Kensington Tonalite DASFRED100K055 | DASFRED100K047 CZu Mafic and ultramafic rocks This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZsf Felsic schist of the Sams Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cl Laurel Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZib Metabasalt of the Ijamsville Phyllite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cf Undivided rocks of the Frederick Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Csqm Middle member of the Sugarloaf Mountain Quartzite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Yqp Quartz-plagioclase gneiss This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Oq Quartz bodies This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZicp Chloritic phyllite of the Ijamsville Phyllite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Obrr Rockdale Run Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ypb Megacrystic metagranite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Zcm Metabasalt of the Catoctin Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Dg Guilford Granite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cca Antietam Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Qcc Coarse colluvium This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Zsp Phyllite of the Swift Run Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ym Marshall Metagranite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cclp Phyllite of the Loudoun Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ccb Big Spring Station Member of the Conococheague Limestone This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Zfsc Boulder conglomerate of the Swains Mountain Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZmbq Quartzite of the Marburg Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZmt Metatuff of the Mather Gorge Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Zrd Metarhyolite dike This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Zsm Marble of the Swift Run Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cuq Quartzite of the Urbana Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZip Phyllite of the Ijamsville Phyllite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Jdc High-titanium quartz-normative early cumulates This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Zcp Tuffaceous phyllite of the Catoctin Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ygt Garnetiferous metagranite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Jmh Hickory Grove Basalt This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZmp Phyllonite of the Mather Gorge Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZg Metagabbro and metapyroxenite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZn Northwest Branch Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Dp Pegmatite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ogg Quartz gabbro of the Georgetown Intrusive Suite Fleming, A.H., Drake, A.A., Jr., and McCartan, Lucy, 1994, Geologic map of the Washington West quadrangle, District of Columbia, Montgomery and Prince Georges Counties, Maryland, and Arlington and Fairfax Counties, Virginia: U.S. Geological Survey Geologic Quadrangle Map GQ– 1748, scale 1:24,000. CZmbb Metabasalt of the Marburg Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZsb Metabasalt of the Sams Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Trcbl Leesburg Member of the Bull Run Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Zcs Metasedimentary phyllite of the Catoctin Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Jdh High-titanium quartz-normative late cumulates This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZsm Marble of the Sams Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZp Prettyboy Schist This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cwac Chewsville Member of the Waynesboro Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Trcbb Balls Bluff Member of the Bull Run Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. OCgu Upper Member of the Grove Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ccs Cash Smith Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ogh Biotite-hornblende tonalite of the Georgetown Intrusive Suite DASFRED100K033 | DASFRED100K047 Zss Metasandstone and schist of the Swift Run Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Yp Garnet-graphite paragneiss This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cwact Cavetown Member of the Waynesboro Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Trcmp Poolesville Member of the Manassas Sandstone This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZmg Metagraywacke of the Mather Gorge Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Jcm Mount Zion Church Basalt This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZiq Quartzite of the Ijamsville Phyllite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Zmd Metadiabase dike This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Jmss Sandstone and siltstone of the Sander Basalt This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Car Araby Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZshp Hematitic phyllite of the Sams Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Jmm Midland Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZlm Semipelitic schist and meta-arenite of the Loch Raven Schist This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZsq Quartzite of the Sams Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Jmtc Conglomerate of the Turkey Run Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ctf Fort Duncan Member of the Tomstown Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZo Oella Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ccp Carbonaceous phyllite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cwar Red Run Member of the Waynesboro Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Zcr Metarhyolite of the Catoctin Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZw Wakefield Marble This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Zcma Marble of the Catoctin Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZil Metalimestone of the Ijamsville Phyllite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Yg White leucocratic metagranite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cchs Metasandstone of the Harpers Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZmbg Metagraywacke of the Marburg Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ce Elbrook Limestone This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ypg Porphyroblastic metagranite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Odm Biotite monzogranite and granodiorite of the Dalecarlia Intrusive Suite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ccwb Buzzard Knob Member of the Weverton Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ont Biotite-hornblende tonalite of the Norbeck Intrusive Suite Hopson, C.A., 1964, The crystalline rocks of Howard and Montgomery Counties, Md., in The geology of Howard and Montgomery Counties: Baltimore, Maryland Geological Survey, p. 27–215. Ogp Metapyroxenite of the Georgetown Intrusive Suite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZsl Metalimestone of the Sams Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Obps Pinesburg Station Dolomite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Zfcr Carter Run Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZms Quartz-rich schist of the Mather Gorge Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Onu Ultramafic rocks of the Norbeck Intrusive Suite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Yhm Hornblende monzonite gneiss This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ya Amphibolite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ccwo Owens Creek Member of the Weverton Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. JTrcc Catharpin Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZsmp Muscovitic phyllite of the Sams Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Yq Quartzite and quartz-sericite tectonite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZim Marble of the Ijamsville Phyllite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cch Harpers Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ctb Benevola Member of the Tomstown Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Trcmt Tuscarora Creek Member of the Manassas Sandstone This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZsd Soldiers Delight Ultramafite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZsqp Quartzite interbedded with phyllite of the Sams Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Kps Potomac Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. OCgl Lower Member of the Grove Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Qr Residuum This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZic Phyllitic conglomerate of the Ijamsville Phyllite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZss Metasiltstone of the Sams Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Oc Chambersburg Limestone This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZicm Conglomeratic metagraywacke of the Ijamsville Phyllite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. JTrccg Goose Creek Member of the Catharpin Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. JTrtm Thermally metamorphosed rocks This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Qcf Fine colluvium This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ymc Coarse-grained metagranite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Odt Muscovitic trondhjemite of the Dalecarlia Intrusive Suite Fleming, A.H., Drake, A.A., Jr., and McCartan, Lucy, 1994, Geologic map of the Washington West quadrangle, District of Columbia, Montgomery and Prince Georges Counties, Maryland, and Arlington and Fairfax Counties, Virginia: U.S. Geological Survey Geologic Quadrangle Map GQ– 1748, scale 1:24,000. CZstp Tuffaceous phyllite of the Sams Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ccwmq Quartzite of the Maryland Heights Member of the Weverton Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ontr Trondhjemite of the Norbeck Intrusive Suite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Osnr New Market and Row Park Limestones undivided, of the St. Paul Group This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ybg Biotite granite gneiss This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Odl Leucocratic muscovite-biotite monzogranite of the Dalecarlia Intrusive Suite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ctbh Bolivar Heights Member of the Tomstown Formation Brezinski, D.K., 1996, Stratigraphy of the Elbrook Formation (Middle to Upper Cambrian) in Maryland and adjacent States, in Brezinski, D.K., and J.P. Reger, eds., Studies in Maryland geology: Maryland Geological Survey Special Publication 3, p. 165–186. CZmm Migmatite of the Mather Gorge Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZmbs Metasiltstone of the Marburg Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. OCc Conococheague Limestone This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Clu Upper part of the Laurel Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Trcmr Reston Member of the Manassas Sandstone This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cfr Rocky Springs Station Member of the Frederick Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Jdg Granophyre This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Yml Pink leucocratic metagranite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ct* Tomstown Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Jd Crystalline diabase This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Trcbg Groveton member of the Bull Run Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Qa Alluvium This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Obss Stoufferstown Member of the Stonehenge Limestone This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Name Name of map unit, as shown in boldface in traditional DMU, e.g., "Shnabkaib Member". Identifies unit within its hierarchical context. GeMS Unrepresentable domain FullName Name of map unit including identification of containing higher rank unit(s), e.g., "Shnabkaib Member of Moenkopi Formation". GeMS Unrepresentable domain Age Age of map unit as shown in Description of Map Units. Examples of values are "late Holocene", "Pliocene and Miocene", "Lower Cretaceous". GeMS Unrepresentable domain Description Free-format text description of map unit. Commonly structured according to one or more accepted traditions (e.g., lithology, thickness, color, weathering and outcrop characteristics, distinguishing features, genesis, age constraints) and terse. GeMS Unrepresentable domain HierarchyKey String that records hierarchical structure. Has form nn-nn-nn, nnn-nnn, or similar. Numeric, left-padded with zeros, dash-delimited. Each HierarchyKey fragment of each row MUST be the same length to allow text-based sorting of table entries. GeMS Unrepresentable domain ParagraphStyle Token that identifies formatting of paragraph(s) within traditional Description of Map Units that correspond to this table entry. GeMS DMU Heading 1 Times New Roman, Bold, 12 pt, 12 pt leading, all caps, centered U.S. Geological Survey Science Publishing Network, MapStyleGuide_DMU_print_1sht_v1-1_01-15.pdf. DMU Unit 1 Times New Roman, Regular, 10 pt, 12 pt leading, left justified, 66 pt left indent, –20 pt 1st line indent U.S. Geological Survey Science Publishing Network, MapStyleGuide_DMU_print_1sht_v1-1_01-15.pdf. DMU Heading 3 Times New Roman, Regular, 10 pt, 12 pt leading, all caps, centered, 10 pt space before U.S. Geological Survey Science Publishing Network, MapStyleGuide_DMU_print_1sht_v1-1_01-15.pdf. DMU Unit 2 Times New Roman, Regular, 10 pt, 12 pt leading, left justified, 66 pt left indent, –10 pt 1st line indent U.S. Geological Survey Science Publishing Network, MapStyleGuide_DMU_print_1sht_v1-1_01-15.pdf. DMU Heading 4 Times New Roman, Regular, 10 pt, 12 pt leading, centered, 8 pt space before U.S. Geological Survey Science Publishing Network, MapStyleGuide_DMU_print_1sht_v1-1_01-15.pdf. DMU Heading 2 Times New Roman, Bold, 10 pt, 12 pt leading, all caps, centered, 12 pt space before U.S. Geological Survey Science Publishing Network, MapStyleGuide_DMU_print_1sht_v1-1_01-15.pdf. DMU Unit 3 Times New Roman, Regular, 10 pt, 12 pt leading, left justified, 66 pt left indent, 0 pt 1st line indent U.S. Geological Survey Science Publishing Network, MapStyleGuide_DMU_print_1sht_v1-1_01-15.pdf. Label Plain-text equivalent of the desired annotation for a feature: for example "14 Ma", or "^c" which (when used with the FGDC GeoAge font) results in the geologic map-unit label TRc (with TR run together to make the Triassic symbol). GeMS Unrepresentable domain Symbol Reference to a point marker, line symbol, or area-fill symbol that is used on the map graphic to denote the feature: perhaps a star for a K-Ar age locality, or a heavy black line for a fault. GeMS Unrepresentable domain AreaFillRGB {Red, Green, Blue} tuples that specify the suggested color (e.g., "255,255,255", "124,005,255") of area fill for symbolizing MapUnit. Each color value is an integer between 0 and 255, values are zero-padded to a length of 3 digits, and values are separated by commas with no space: NNN,NNN,NNN. GeMS Unrepresentable domain AreaFillPatternDescription Text description (e.g., "random small red dashes") provided as a convenience for users who must recreate symbolization. GeMS Unrepresentable domain DescriptionSourceID Source of map-unit description; foreign key to table Datasources. GeMS DASFRED100K012 Brezinski, D.K., 1996, Stratigraphy of the Elbrook Formation (Middle to Upper Cambrian) in Maryland and adjacent States, in Brezinski, D.K., and J.P. Reger, eds., Studies in Maryland geology: Maryland Geological Survey Special Publication 3, p. 165–186. This report DASFRED100K055 Hopson, C.A., 1964, The crystalline rocks of Howard and Montgomery Counties, Md., in The geology of Howard and Montgomery Counties: Baltimore, Maryland Geological Survey, p. 27–215. This report DASFRED100K055 | DASFRED100K047 DASFRED100K055 | DASFRED100K047 This report DASFRED100K047 Fleming, A.H., Drake, A.A., Jr., and McCartan, Lucy, 1994, Geologic map of the Washington West quadrangle, District of Columbia, Montgomery and Prince Georges Counties, Maryland, and Arlington and Fairfax Counties, Virginia: U.S. Geological Survey Geologic Quadrangle Map GQ– 1748, scale 1:24,000. This report DASFRED100K003 This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. This report DASFRED100K033 | DASFRED100K047 DASFRED100K033 | DASFRED100K047 This report GeoMaterial Categorization of map unit based on lithologic and genetic character, term selected from NGMDB standard term list defined in Appendix A of GeMS documentation, available at http://ngmdb.usgs.gov/Info/standards/GeMS.. GeMS Meta-carbonate rock Rock derived from preexisting carbonate sedimentary rocks and altered by essentially solid-state mineralogical, chemical, or structural changes, in response to marked changes in temperature, pressure, deformation, and (or) chemical environment, generally at depth in Earths crust. Characterized by recrystallization of carbonate minerals in source rock. Includes marble (for which preexisting rock was dominantly limestone or other rock composed of calcite), dolomitic marble, meta-dolostone, and meta-dolomite (for which preexisting rock contained appreciable amount of magnesium). GeMS Colluvium and other widespread mass-movement sediment Sediment formed by slow, relatively widespread, downslope transport of particles or clasts produced by weathering and breakdown of underlying rock, sediment, and (or) soil. Composed of poorly sorted and poorly stratified material that ranges in size from clay to boulders. GeMS Metasedimentary rock Rock derived from preexisting sedimentary rocks and altered by essentially solid-state mineralogical, chemical, or structural changes, in response to marked changes in temperature, pressure, deformation, and (or) chemical environment, generally at depth in Earths crust. GeMS Alluvial sediment Unconsolidated material deposited by streams or other bodies of running water as sorted or semisorted sediment in streambed, or on its floodplain or delta, or as cone or fan at base of mountain slope. Grain size varies from clay to gravel. GeMS Igneous and metamorphic rock Consists of coarse-grained intrusive igneous rock and generally medium- to high-grade metamorphic rock. GeMS Medium and high-grade regional metamorphic rock, of unspecified origin Rock derived from preexisting rocks and altered by essentially solid-state mineralogical, chemical, or structural changes, in response to relatively intense regional changes in temperature, pressure, deformation, and (or) chemical environment, generally at depth in Earths crust. Origin of preexisting rock is mixed (for example, igneous and sedimentary) or is not known. Includes amphibolite, granulite, schist, and gneiss. GeMS Residual material Unconsolidated material, developed in place by weathering of underlying rock or sediment. Usually forms relatively thin surface layer that conceals unweathered or partly altered source material. Material from which soils are formed. GeMS Mafic-composition lava flows Lateral, surficial outpourings of molten lava from vent or fissure; also, solidified bodies of rock that form when they cool. Low-silica parental magmas have low viscosity and tend to form extensive sheets that have generally low relief. Includes basaltic shield volcanoes, which may become very large (for example, in Hawaii). Composed of fine-grained, dark rocks, including basaltic. GeMS Mostly carbonate rock Mostly carbonate rock, interbedded with other sedimentary rock types. GeMS Coarse-grained, felsic-composition intrusive igneous rock Rock that solidified from molten or partly molten material (magma) at some depth beneath Earths surface, thereby cooling slowly enough for mineral crystals to grow large enough to be visible to naked eye. Composed mostly of light-colored minerals (for example, feldspar, quartz). Includes granitic, syenitic, and monzonitic rock. GeMS Schist and gneiss, of sedimentary-rock origin Foliated rock derived from preexisting sedimentary rocks by essentially solid-state mineralogical, chemical, or structural changes in response to marked changes in temperature, pressure, deformation, and (or) chemical environment, generally at depth in Earths crust. Includes schist (characterized by such strong foliation or alignment of minerals that it readily splits into flakes or slabs) and gneiss (characterized by alternating, irregular bands of different mineral composition). Mostly formed from fine-grained material such as mudstone. GeMS Fine-grained, intermediate-composition intrusive igneous rock Rock that solidified from molten or partly molten material (magma) at shallow depth beneath Earths surface, thereby cooling quickly. Generally fine grained but may contain large mineral crystals (phenocrysts). Mostly found as tabular dikes or sills. Intermediate in color and in mineral composition (between felsic and mafic igneous rock). Includes andesitic rock. GeMS Quartzite Rock derived from preexisting quartz-rich sedimentary rocks (commonly sandstone) and altered by essentially solid-state mineralogical, chemical, or structural changes, in response to marked changes in temperature, pressure, shear stress, and (or) chemical environment, generally at depth in Earths crust. GeMS Mostly sandstone Mostly sandstone, interbedded with other sedimentary rocks that locally may include conglomerate and finer grained clastic rocks (mudstone), carbonates, and (or) coal. GeMS Meta-felsic and intermediate rock Rock derived from preexisting felsic and intermediate-composition rocks by essentially solid-state, mineralogical, chemical, or structural changes, in response to marked changes in temperature, pressure, deformation, and (or) chemical environment, generally at depth in Earths crust. Composed mostly of light-colored minerals; relatively enriched in silica. Includes metagranite, metadiorite, and meta-andesite. GeMS Contact-metamorphic rock Altered rock that originated by local processes of thermal metamorphism, genetically related to intrusion and extrusion of magmas and taking place at or near contact with body of igneous rock. Metamorphic changes are effected by heat and fluids emanating from magma and by some deformation because of emplacement of igneous mass. GeMS Meta-volcaniclastic rock Rock derived from preexisting volcaniclastic rocks by essentially solid-state, mineralogical, chemical, or structural changes, in response to marked changes in temperature, pressure, deformation, and (or) chemical environment, generally at depth in Earths crust. Composed of deformed but recognizable particles or clasts of volcanic explosive material. GeMS Dolomite Carbonate sedimentary rock, consisting chiefly of dolomite. Although dolostone is the proper analog to limestone, it has not often been applied to dolomitic units. GeMS Mostly mudstone Mostly mudstone, interbedded with other sedimentary rocks that locally may include coarser grained clastic rocks (sandstone, conglomerate), carbonates, and (or) coal. GeMS Conglomerate Sedimentary rock, composed predominantly of particles or clasts derived by erosion and weathering of preexisting rock; contains more than 30 percent gravel-sized clasts. GeMS Alluvial sediment, mostly coarse-grained Unconsolidated material deposited by streams or other bodies of running water as sorted or semisorted sediment in streambed, or on its floodplain or delta, or as cone or fan at base of mountain slope. Sediment is mostly sand, gravel, and coarser material but may also contain some silt and clay. GeMS Alluvial sediment, mostly fine-grained Unconsolidated material deposited by streams or other bodies of running water as sorted or semisorted sediment in streambed, or on its floodplain or delta, or as cone or fan at base of mountain slope. Sediment is mostly silt and clay but may also contain some sand and gravel. GeMS Lower-grade metamorphic rock, of unspecified origin Rock derived from preexisting rocks and altered by essentially solid-state mineralogical, chemical, or structural changes, in response to relatively mild regional changes in temperature, pressure, deformation, and (or) chemical environment, generally at depth in Earths crust. Origin of preexisting rock is mixed (for example, igneous and sedimentary) or is not known. Includes slate and phyllite. GeMS Sandstone and mudstone Sandstone and mudstone (including shale and siltstone), in approximately equal (or unspecified) proportions. GeMS Coarse-grained, mafic-composition intrusive igneous rock Rock that solidified from molten or partly molten material (magma) at some depth beneath Earths surface, thereby cooling slowly enough for mineral crystals to grow large enough to be visible to naked eye. Composed mostly of feldspar and dark-colored minerals. Includes gabbroic rock. GeMS Limestone Carbonate sedimentary rock, consisting chiefly of calcite. GeMS Carbonate rock Sedimentary rock, consisting chiefly of carbonate minerals such as limestone or dolomite. GeMS Sedimentary rock Consolidated material (rock) composed of particles transported and deposited by gravity, air, water, or ice, or accumulated by other natural agents operating at Earths surface, such as chemical precipitation or secretion by organisms. Does not here include sedimentary material directly deposited as result of volcanic activity. GeMS Coarse-grained, intermediate-composition intrusive igneous rock Rock that solidified from molten or partly molten material (magma) at some depth beneath Earths surface, thereby cooling slowly enough for mineral crystals to grow large enough to be visible to naked eye. Intermediate in color and in mineral composition (between felsic and mafic igneous rock). Includes dioritic rock. GeMS Clastic sedimentary rock Sedimentary rock, composed predominantly of particles or clasts derived by erosion, weathering, or mass-wasting of preexisting rock and deposited by gravity, air, water, or ice. GeMS Slate and phyllite, of sedimentary-rock origin Fine-grained rock derived from preexisting sedimentary rocks and altered by essentially solid-state mineralogical, chemical, or structural changes, in response to marked changes in temperature, pressure, deformation, and (or) chemical environment, generally at depth in Earths crust. Includes phyllite and slate (compact, fine-grained rock that possesses strong cleavage and, hence, can be split into slabs and thin plates). Mostly formed from fine-grained material such as mudstone. GeMS Metaigneous rock Rock derived from preexisting igneous rocks and altered by essentially solid-state, mineralogical, chemical, or structural changes, in response to marked changes in temperature, pressure, shear stress, and (or) chemical environment, generally at depth in Earths crust. GeMS Meta-ultramafic rock Rock derived from preexisting ultramafic rocks by essentially solid-state, mineralogical, chemical, or structural changes, in response to marked changes in temperature, pressure, deformation, and (or) chemical environment, generally at depth in Earths crust. Composed mostly of magnesium-bearing minerals (for example, serpentine, talc, magnesite). GeMS Meta-mafic rock Rock derived from preexisting mafic rocks by essentially solid-state, mineralogical, chemical, or structural changes, in response to marked changes in temperature, pressure, deformation, and (or) chemical environment, generally at depth in Earths crust. Composed mostly of iron- and magnesium-bearing, dark-colored and (or) green minerals. Includes greenstone, amphibolite, and metagabbro. GeMS GeoMaterialConfidence Describes appropriateness of GeoMaterial term for describing the map unit. GeMS High The term and definition adequately characterize the overall lithologic nature of rocks and sediments in the map unit. Regarding the subjective term "adequately characterize", we refer to context and objectives of this classification as described in the GeMS documentation. GeMS documentation Medium The term and definition generally characterize the overall lithology of the map unit, but there are one or more significant minor lithologies that are not adequately described by the selected term. GeMS documentation Low The overall lithology of this map unit is not adequately classifiable using this list of terms and definitions, but the term selected is the best available. Or this map unit is insufficiently known to confidently assign a GeoMaterial term. GeMS documentation DescriptionOfMapUnits_ID Primary key. GeMS Arbitrary string. Values should be unique within this database. DataSources Non-spatial table of sources of all spatial features, sources of some attributes of spatial features, and sources of some attributes of non-spatial table entries. GeMS OBJECTID Internal feature number ESRI Unrepresentable domain Source Plain-text short description that identifies the data source. GeMS Unrepresentable domain Notes Additional information specific to a particular feature or table entry. GeMS Unrepresentable domain. Free text. Values of <null> or #null indicate no entry. URL Universal Resource Locator (URL) or Document Object Identifier (DOI), identifies a document on the World Wide Web. GeMS Unrepresentable domain DataSources_ID Primary key. GeMS Arbitrary string. Values should be unique within this database. Glossary Non-spatial table that, for certain fields (including all Type fields, Confidence fields, and GeneralLithology), lists the terms that populate these fields, term definitions, and sources for definitions. GeMS OBJECTID Internal feature number ESRI Unrepresentable domain Term Plain-language word for a concept. Values must be unique within database as a whole. GeMS Unrepresentable domain Definition Plain-language definition. GeMS Unrepresentable domain DefinitionSourceID Source of definition; foreign key to DataSources. GeMS FGDC Federal Geographic Data Committee [prepared for the Federal Geographic Data Committee by the U.S. Geological Survey], 2006, FGDC Digital Cartographic Standard for Geologic Map Symbolization: Reston, Va., Federal Geographic Data Committee Document Number FGDC-STD-013-2006, 290 p., 2 plates. This report AGI | DASFRED100K003 DASFRED100K033 | DASFRED100K047 This report USGS U.S. Geological Survey Science Publishing Network, MapStyleGuide_DMU_print_1sht_v1-1_01-15.pdf. This report AGI Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2011, Glossary of geology (5th ed., revised): Alexandria, Va., American Geosciences Institute, 783 p. This report GeMS U.S. Geological Survey National Cooperative Geologic Mapping Program, 2020, GeMS (Geologic Map Schema)—A standard format for the digital publication of geologic maps: U.S. Geological Survey Techniques and Methods, book 11, chap. B10, 74 p. This report DASFRED100K003 This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. This report DASFRED100K052 Gunderson, L.C.S., Reimer, G.M., Wiggs, C.R., and Rice, C.A., 1988, Map showing radon potential of rocks and soils in Montgomery County, Maryland: U.S. Geological Survey Miscellaneous Field Studies Map MF–2043, scale 1:62,500. This report Glossary_ID Primary key. GeMS Arbitrary string. Values should be unique within this database. GeoMaterialDict Non-spatial table that provides values of GeoMaterial, placed in a hierarchy, and their definitions. For further information, see Appendix A in GeMS documentation, available at http://ngmdb.usgs.gov/Info/standards/GeMS. GeMS OBJECTID Internal feature number ESRI Unrepresentable domain HierarchyKey String that records hierarchical structure. Has form nn-nn-nn, nnn-nnn, or similar. Numeric, left-padded with zeros, dash-delimited. Each HierarchyKey fragment of each row MUST be the same length to allow text-based sorting of table entries. GeMS Unrepresentable domain GeoMaterial Categorization of map unit based on lithologic and genetic character, term selected from NGMDB standard term list defined in Appendix A of GeMS documentation, available at http://ngmdb.usgs.gov/Info/standards/GeMS.. GeMS Playa sediment Fine-grained clastic sediment and evaporitic salts, deposited in ephemeral lakes in centers of undrained basins. Includes material deposited in playas, mud flats, salt flats, and adjacent saline marshes. Generally interbedded with eolian sand and with lacustrine sediment deposited during wetter climatic periods; commonly intertongues upslope with sediment deposited by alluvial fans. GeMS Mass movement sediment Sediment formed by downslope transport of particles or clasts produced by weathering and breakdown of underlying rock, sediment, and (or) soil. Composed of poorly sorted and poorly stratified material that ranges in size from clay to boulders. Includes colluvial, landslide, talus, and rock-avalanche deposits. GeMS Colluvium and other widespread mass-movement sediment Sediment formed by slow, relatively widespread, downslope transport of particles or clasts produced by weathering and breakdown of underlying rock, sediment, and (or) soil. Composed of poorly sorted and poorly stratified material that ranges in size from clay to boulders. GeMS Residual material Unconsolidated material, developed in place by weathering of underlying rock or sediment. Usually forms relatively thin surface layer that conceals unweathered or partly altered source material. Material from which soils are formed. GeMS Chert Sedimentary rock, composed chiefly of microcrystalline or cryptocrystalline quartz. GeMS Deformation-related metamorphic rock Rock derived from preexisting rocks by essentially solid-state mineralogical, chemical, or structural changes in response to strong deformation, commonly in association with marked changes in temperature, pressure, and (or) chemical environment. Generally forms in narrow, planar zones of local deformation (for example, along faults); characterized by foliation or alignment of mineral grains. Includes mylonite and cataclasite. GeMS Intrusive igneous rock Rock that solidified from molten or partly molten material (magma) below Earths surface. GeMS Marine sediment Mud and sand, deposited in various marine environments. May originate from erosion of rocks and sediment or may be derived from marine organisms (of carbonate or siliceous composition). GeMS Meta-felsic and intermediate rock Rock derived from preexisting felsic and intermediate-composition rocks by essentially solid-state, mineralogical, chemical, or structural changes, in response to marked changes in temperature, pressure, deformation, and (or) chemical environment, generally at depth in Earths crust. Composed mostly of light-colored minerals; relatively enriched in silica. Includes metagranite, metadiorite, and meta-andesite. GeMS Meta-volcaniclastic rock Rock derived from preexisting volcaniclastic rocks by essentially solid-state, mineralogical, chemical, or structural changes, in response to marked changes in temperature, pressure, deformation, and (or) chemical environment, generally at depth in Earths crust. Composed of deformed but recognizable particles or clasts of volcanic explosive material. GeMS Alluvial sediment, mostly fine-grained Unconsolidated material deposited by streams or other bodies of running water as sorted or semisorted sediment in streambed, or on its floodplain or delta, or as cone or fan at base of mountain slope. Sediment is mostly silt and clay but may also contain some sand and gravel. GeMS Ice-contact and ice-marginal sediment, mostly coarse-grained Mostly sand- and gravel-sized particles or clasts, with lesser amounts of silt and clay, derived from rock or preexisting sediment that has been eroded and transported by glaciers. As glacier melted, material was deposited by running water essentially in contact with glacial ice or was transported and deposited by glacially fed streams. Includes sediment deposited into water bodies adjacent to glacier. GeMS Lower-grade metamorphic rock, of unspecified origin Rock derived from preexisting rocks and altered by essentially solid-state mineralogical, chemical, or structural changes, in response to relatively mild regional changes in temperature, pressure, deformation, and (or) chemical environment, generally at depth in Earths crust. Origin of preexisting rock is mixed (for example, igneous and sedimentary) or is not known. Includes slate and phyllite. GeMS Felsic-composition lava flows Lateral, surficial outpourings of molten lava from vent or fissure; also, solidified bodies of rock that form when they cool. Because of their high silica content and resulting high viscosity, parental magmas tend to erupt explosively, and so these deposits are uncommon. Includes fine-grained, light-colored rock with rhyolitic, dacitic, trachytic, and latitic composition. GeMS Carbonate rock Sedimentary rock, consisting chiefly of carbonate minerals such as limestone or dolomite. GeMS Sedimentary rock Consolidated material (rock) composed of particles transported and deposited by gravity, air, water, or ice, or accumulated by other natural agents operating at Earths surface, such as chemical precipitation or secretion by organisms. Does not here include sedimentary material directly deposited as result of volcanic activity. GeMS Coarse-grained, intermediate-composition intrusive igneous rock Rock that solidified from molten or partly molten material (magma) at some depth beneath Earths surface, thereby cooling slowly enough for mineral crystals to grow large enough to be visible to naked eye. Intermediate in color and in mineral composition (between felsic and mafic igneous rock). Includes dioritic rock. GeMS Clastic sedimentary rock Sedimentary rock, composed predominantly of particles or clasts derived by erosion, weathering, or mass-wasting of preexisting rock and deposited by gravity, air, water, or ice. GeMS Slate and phyllite, of sedimentary-rock origin Fine-grained rock derived from preexisting sedimentary rocks and altered by essentially solid-state mineralogical, chemical, or structural changes, in response to marked changes in temperature, pressure, deformation, and (or) chemical environment, generally at depth in Earths crust. Includes phyllite and slate (compact, fine-grained rock that possesses strong cleavage and, hence, can be split into slabs and thin plates). Mostly formed from fine-grained material such as mudstone. GeMS Water or ice Water or ice GeMS Coarse-grained intrusive igneous rock Rock that solidified from molten or partly molten material (magma) at some depth beneath Earths surface, thereby cooling slowly enough for mineral crystals to grow large enough to be visible to naked eye. GeMS Carbonate sediment Sediment formed by biotic or abiotic precipitation from aqueous solution of carbonates of calcium, magnesium, or iron (for example, limestone, dolomite). GeMS Sedimentary and extrusive igneous material Either (1) sedimentary rock and (or) unconsolidated material (sediment) and extrusive igneous material (volcanic rock and [or] sediment) or (2) volcanic rock and (or) sediment and such material after erosion and redeposition. GeMS Metamorphic rock Rock derived from preexisting rocks and altered by essentially solid-state mineralogical, chemical, or structural changes, in response to marked changes in temperature, pressure, deformation, and (or) chemical environment, generally at depth in Earths crust. GeMS Alluvial sediment Unconsolidated material deposited by streams or other bodies of running water as sorted or semisorted sediment in streambed, or on its floodplain or delta, or as cone or fan at base of mountain slope. Grain size varies from clay to gravel. GeMS Coastal zone sediment Mud and sand, with lesser amounts of gravel, deposited on beaches, on barrier islands, or in nearshore-marine, deltaic, or various low-energy shoreline (mud flat, tidal flat, sabka, algal flat) environments. GeMS Igneous and metamorphic rock Consists of coarse-grained intrusive igneous rock and generally medium- to high-grade metamorphic rock. GeMS "Made" or human-engineered land Modern, unconsolidated material known to have human-related origin. GeMS Mudstone Sedimentary rock, composed predominantly of particles or clasts derived by erosion and weathering of preexisting rock; consists mostly of mud (that is, silt- and clay-sized particles). Includes shale and siltstone. GeMS Mafic-composition lava flows Lateral, surficial outpourings of molten lava from vent or fissure; also, solidified bodies of rock that form when they cool. Low-silica parental magmas have low viscosity and tend to form extensive sheets that have generally low relief. Includes basaltic shield volcanoes, which may become very large (for example, in Hawaii). Composed of fine-grained, dark rocks, including basaltic. GeMS Peat and muck Unconsolidated material, principally composed of plant remains, with lesser amounts of fine-grained clastic sediment. Deposited in water-saturated environment such as swamp, marsh, or bog. With lithification, such material becomes coal. GeMS Intermediate-composition pyroclastic flows Hot ash, pumice, and rock fragments erupted from volcano. Material moves downslope commonly in chaotic flows; once deposited, hot fragments may compact under their own weight and weld together. Parental magma commonly erupts from stratovolcanoes as thick lava flows but also can generate strong explosive eruptions to form pyroclastic flows. Includes rocks that are, in color and mineral composition, intermediate between felsic and mafic rocks (for example, andesite). GeMS Exotic-composition intrusive igneous rock Rock that solidified from molten or partly molten material (magma) below Earths surface that has exotic mineralogical, textural, or field setting characteristics. Typically dark colored with abundant phenocrysts. Includes kimberlite, lamprophyre, lamproite, and foiditic rocks. GeMS Loess Silty sediment, deposited by wind, commonly near glacial margin. GeMS Rock and sediment Various rocks and sediment, not differentiated. GeMS Sand and gravel of unspecified origin Sediment composed mostly of sand and (or) gravel, formed by weathering and erosion of preexisting rocks or minerals; eroded particles or clasts are transported and deposited by gravity, air, water, or ice. GeMS Contact-metamorphic rock Altered rock that originated by local processes of thermal metamorphism, genetically related to intrusion and extrusion of magmas and taking place at or near contact with body of igneous rock. Metamorphic changes are effected by heat and fluids emanating from magma and by some deformation because of emplacement of igneous mass. GeMS Alluvial sediment, mostly coarse-grained Unconsolidated material deposited by streams or other bodies of running water as sorted or semisorted sediment in streambed, or on its floodplain or delta, or as cone or fan at base of mountain slope. Sediment is mostly sand, gravel, and coarser material but may also contain some silt and clay. GeMS Marine sediment, mostly fine-grained Mostly clay- and silt-sized sediment, deposited in relatively deep, quiet water, far removed from areas where coarser grained clastic sediments are washed into marine environment. Includes sediment derived from marine organisms. GeMS Felsic-composition air-fall tephra Fragments of volcanic rock and lava, of various sizes, carried into air by explosions and by hot gases in eruption columns or lava fountains; known as tephra. As tephra falls to ground, with increasing distance from volcano, average size of individual rock particles and thickness of resulting deposit decrease. Because of their high silica content and resulting high viscosity, felsic-composition magmas tend to erupt explosively, readily forming pumice and volcanic ash. Composed of light-colored rocks (for example, rhyolite, dacite, trachyte, latite). GeMS Air-fall tephra Fragments of volcanic rock and lava, of various sizes, carried into air by explosions and by hot gases in eruption columns or lava fountains; known as tephra. As tephra falls to ground, with increasing distance from volcano, average size of individual rock particles and thickness of resulting deposit decrease. Fine tephra deposited at some distance from volcano is known as volcanic ash. GeMS Dune sand Mostly sand-sized sediment, deposited by wind. Typically characterized by various dune landforms. GeMS Coastal zone sediment, mostly fine-grained Mostly clay and silt, deposited in lagoons, tidal flats, backbarriers, and coastal marshes. GeMS Rock Various rock types, not differentiated. GeMS Mafic-composition air-fall tephra Fragments of volcanic rock and lava, of various sizes, carried into the air by explosions and by hot gases in eruption columns or lava fountains; known as tephra. As tephra falls to ground, with increasing distance from volcano, average size of individual rock particles and thickness of resulting deposit decrease. Because of their low silica content and resulting low viscosity, parental magmas tend to erupt gently as lava flows, and so these deposits are uncommon. Includes basalt; rocks are commonly dark-colored. GeMS Glacial till, mostly clayey Mostly unsorted and unstratified material, generally unconsolidated, deposited directly by and underneath or adjacent to glacier without subsequent reworking by meltwater. Consists of heterogeneous mixture of clay, silt, sand, gravel, and boulders, ranging widely in size and shape. Relatively clayey in texture. GeMS Lacustrine sediment Mostly well-sorted and well-bedded material that ranges in grain size from clay to gravel, deposited in perennial to intermittent lakes. Much of sediment is derived from material eroded and transported by streams. Includes deposits of lake-marginal beaches and deltas. GeMS Intermediate-composition air-fall tephra Fragments of volcanic rock and lava, of various sizes, carried into the air by explosions and by hot gases in eruption columns or lava fountains; known as tephra. As tephra falls to ground, with increasing distance from volcano, average size of individual rock particles and thickness of resulting deposit decrease. Parental magma commonly erupts from stratovolcanoes as thick lava flows but also can generate strong explosive eruptions to form pyroclastic flows. Includes rocks that are, in color and mineral composition, intermediate between felsic and mafic rocks (for example, andesite). GeMS Other materials Other materials GeMS Pyroclastic flows Hot ash, pumice, and rock fragments erupted from volcano or caldera. Material moves downslope commonly in chaotic flows; once deposited, hot fragments may compact under their own weight and weld together. GeMS Glacial till, mostly sandy Mostly unsorted and unstratified material, generally unconsolidated, deposited directly by and underneath or adjacent to glacier without subsequent reworking by meltwater. Consists of heterogeneous mixture of clay, silt, sand, gravel, and boulders, ranging widely in size and shape. Relatively sandy in texture. GeMS Iron-rich sedimentary rock Sedimentary rock, in which at least half (by volume) of observed minerals are iron bearing (hematite, magnetite, limonite group minerals, siderite, iron sulfides). GeMS Meta-carbonate rock Rock derived from preexisting carbonate sedimentary rocks and altered by essentially solid-state mineralogical, chemical, or structural changes, in response to marked changes in temperature, pressure, deformation, and (or) chemical environment, generally at depth in Earths crust. Characterized by recrystallization of carbonate minerals in source rock. Includes marble (for which preexisting rock was dominantly limestone or other rock composed of calcite), dolomitic marble, meta-dolostone, and meta-dolomite (for which preexisting rock contained appreciable amount of magnesium). GeMS Felsic-composition pyroclastic flows Hot ash, pumice, and rock fragments erupted from volcano or caldera. Material moves downslope commonly in chaotic flows; once deposited, hot fragments may compact under their own weight and weld together. Because of their high-silica content and resulting high viscosity, parental magmas tend to erupt explosively. Includes rhyolite, dacite, trachyte, latite; rocks are commonly light-colored. GeMS Regional metamorphic rock, of unspecified origin Rock derived from preexisting rocks and altered by essentially solid-state mineralogical, chemical, or structural changes, in response to marked regional changes in temperature, pressure, deformation, and (or) chemical environment, generally at depth in Earths crust. Origin of preexisting rock is mixed (for example, igneous and sedimentary) or is not known. GeMS Evaporitic rock Sedimentary rock, composed primarily of minerals produced by evaporation of saline solution. Examples include gypsum, anhydrite, other diverse sulfates, halite (rock salt), primary dolomite, and rocks composed of various nitrates and borates. GeMS Ice-contact and ice-marginal sediment, mostly fine-grained Mostly silt- and clay-sized particles or clasts, with lesser amounts of sand and gravel, derived from rock or preexisting sediment that has been eroded and transported by glaciers. As glacier melted, material was deposited by running water essentially in contact with glacial ice or was transported and deposited by glacially fed streams. Includes sediment deposited into water bodies adjacent to glacier. GeMS Glacial till Mostly unsorted and unstratified material, generally unconsolidated, deposited directly by and underneath or adjacent to glacier without subsequent reworking by meltwater. Consists of heterogeneous mixture of clay, silt, sand, gravel, and boulders, ranging widely in size and shape. GeMS Coarse-grained, felsic-composition intrusive igneous rock Rock that solidified from molten or partly molten material (magma) at some depth beneath Earths surface, thereby cooling slowly enough for mineral crystals to grow large enough to be visible to naked eye. Composed mostly of light-colored minerals (for example, feldspar, quartz). Includes granitic, syenitic, and monzonitic rock. GeMS Quartzite Rock derived from preexisting quartz-rich sedimentary rocks (commonly sandstone) and altered by essentially solid-state mineralogical, chemical, or structural changes, in response to marked changes in temperature, pressure, shear stress, and (or) chemical environment, generally at depth in Earths crust. GeMS Glacial till, mostly silty Mostly unsorted and unstratified material, generally unconsolidated, deposited directly by and underneath or adjacent to glacier without subsequent reworking by meltwater. Consists of heterogeneous mixture of clay, silt, sand, gravel, and boulders, ranging widely in size and shape. Relatively loamy (silty) in texture. GeMS Coal and lignite Organic-rich sedimentary rock, formed from compaction and alteration of plant remains. Coal is consolidated, harder, black rock. Lignite is semiconsolidated, brown to black, earthy material that may contain large particles of recognizable plant parts and tends to crack upon drying. GeMS Dolomite Carbonate sedimentary rock, consisting chiefly of dolomite. Although dolostone is the proper analog to limestone, it has not often been applied to dolomitic units. GeMS Sediment Unconsolidated material (sediment) composed of particles deposited by gravity, air, water, or ice, or as accumulated by other natural agents operating at Earths surface such as chemical precipitation or secretion by organisms. Does not include sedimentary material directly deposited as a result of volcanic activity. GeMS Lacustrine sediment, mostly coarse-grained Mostly well-sorted and well-bedded material, generally sand and gravel sized, with lesser amounts of silt and clay, deposited in perennial to intermittent lakes. Much of sediment is derived from material eroded and transported by streams. Mostly deposits of lake-marginal beaches and deltas. GeMS Ultramafic intrusive igneous rock Rock that solidified from molten or partly molten material (magma) at some depth beneath Earths surface, thereby cooling slowly enough for mineral crystals to grow large enough to be visible to naked eye. Composed almost entirely of mafic minerals (for example, hypersthene, augite, olivine). GeMS Extrusive igneous material Molten material that was erupted onto Earths surface, fusing into rock or remaining as unconsolidated particles. Includes pyroclastic flows, air-fall tephra, lava flows, and volcanic mass flows. GeMS Volcanic mass flow Volcanic deposits formed by mass movement (for example, debris avalanches, debris flows, lahar deposits), in many cases triggered by volcanic eruption. Debris avalanches that occur on volcanoes clearly without eruptive trigger may be classified as sedimentary (for example, as Debris flows, landslides, and other localized mass-movement sediment). GeMS Coarse-grained, mafic-composition intrusive igneous rock Rock that solidified from molten or partly molten material (magma) at some depth beneath Earths surface, thereby cooling slowly enough for mineral crystals to grow large enough to be visible to naked eye. Composed mostly of feldspar and dark-colored minerals. Includes gabbroic rock. GeMS Lava flows Lateral, surficial outpourings of molten lava from vent or fissure; also, solidified bodies of rock that form when they cool. Composed generally of fine-grained, dark-colored rocks (for example, basalt), which tend to form extensive sheets that have generally low relief, except in vent areas where cinder cones or shield volcanoes may form. Includes basaltic shield volcanoes, which may become very large (for example, Hawaii). GeMS Marine sediment, mostly coarse-grained Mud, sand, and gravel eroded from rocks and sediment on land, transported by streams, and deposited in marine deltas and basins. Mostly siliceous in composition. GeMS Volcaniclastic (fragmental) material Rock and unconsolidated material consisting of particles or clasts that were formed by volcanic explosion or aerial expulsion from volcanic vent. GeMS Intermediate-composition lava flows Lateral, surficial outpourings of molten lava from vent or fissure; also, solidified bodies of rock that form when they cool. Parental magma commonly erupts from stratovolcanoes as thick lava flows. Includes rocks that are, in color and in mineral composition, intermediate between felsic and mafic rocks (for example, andesite). GeMS Igneous rock Rock and fragmental material that solidified from molten or partly molten material (magma). GeMS Ice-contact and ice-marginal sediment Mostly sand-, silt-, and gravel-sized particles or clasts derived from rock or preexisting sediment that has been eroded and transported by glaciers. As glacier melted, material was deposited by running water essentially in contact with glacial ice or was transported and deposited by glacially fed streams. Includes sediment deposited into water bodies adjacent to glacier. GeMS Eolian sediment Silt- and sand-sized sediment, deposited by wind. GeMS Metaigneous rock Rock derived from preexisting igneous rocks and altered by essentially solid-state, mineralogical, chemical, or structural changes, in response to marked changes in temperature, pressure, shear stress, and (or) chemical environment, generally at depth in Earths crust. GeMS Unmapped area Unmapped area GeMS Meta-mafic rock Rock derived from preexisting mafic rocks by essentially solid-state, mineralogical, chemical, or structural changes, in response to marked changes in temperature, pressure, deformation, and (or) chemical environment, generally at depth in Earths crust. Composed mostly of iron- and magnesium-bearing, dark-colored and (or) green minerals. Includes greenstone, amphibolite, and metagabbro. GeMS Mafic-composition pyroclastic flows Hot ash, pumice, and rock fragments erupted from volcano. Material moves downslope commonly in chaotic flows; once deposited, hot fragments may compact under their own weight and weld together. Because of their low silica content and resulting low viscosity, parental magmas tend to erupt gently as lava flows rather than more forcefully as pyroclastic flows. Includes basalt; rocks are commonly dark-colored. GeMS Metasedimentary rock Rock derived from preexisting sedimentary rocks and altered by essentially solid-state mineralogical, chemical, or structural changes, in response to marked changes in temperature, pressure, deformation, and (or) chemical environment, generally at depth in Earths crust. GeMS Medium and high-grade regional metamorphic rock, of unspecified origin Rock derived from preexisting rocks and altered by essentially solid-state mineralogical, chemical, or structural changes, in response to relatively intense regional changes in temperature, pressure, deformation, and (or) chemical environment, generally at depth in Earths crust. Origin of preexisting rock is mixed (for example, igneous and sedimentary) or is not known. Includes amphibolite, granulite, schist, and gneiss. GeMS Fine-grained, mafic-composition intrusive igneous rock Rock that solidified from molten or partly molten material (magma) at shallow depth beneath Earths surface, thereby cooling quickly. Generally fine grained but may contain large mineral crystals (phenocrysts). Mostly found as tabular dikes or sills. Composed mostly of dark-colored minerals. Includes basaltic rock. GeMS Mostly carbonate rock Mostly carbonate rock, interbedded with other sedimentary rock types. GeMS Schist and gneiss, of sedimentary-rock origin Foliated rock derived from preexisting sedimentary rocks by essentially solid-state mineralogical, chemical, or structural changes in response to marked changes in temperature, pressure, deformation, and (or) chemical environment, generally at depth in Earths crust. Includes schist (characterized by such strong foliation or alignment of minerals that it readily splits into flakes or slabs) and gneiss (characterized by alternating, irregular bands of different mineral composition). Mostly formed from fine-grained material such as mudstone. GeMS Lacustrine sediment, mostly fine-grained Mostly well-sorted and well-bedded material, generally silt and clay sized, with lesser amounts of sand, deposited in perennial to intermittent lakes. GeMS Fine-grained, intermediate-composition intrusive igneous rock Rock that solidified from molten or partly molten material (magma) at shallow depth beneath Earths surface, thereby cooling quickly. Generally fine grained but may contain large mineral crystals (phenocrysts). Mostly found as tabular dikes or sills. Intermediate in color and in mineral composition (between felsic and mafic igneous rock). Includes andesitic rock. GeMS Mostly sandstone Mostly sandstone, interbedded with other sedimentary rocks that locally may include conglomerate and finer grained clastic rocks (mudstone), carbonates, and (or) coal. GeMS Mostly mudstone Mostly mudstone, interbedded with other sedimentary rocks that locally may include coarser grained clastic rocks (sandstone, conglomerate), carbonates, and (or) coal. GeMS Conglomerate Sedimentary rock, composed predominantly of particles or clasts derived by erosion and weathering of preexisting rock; contains more than 30 percent gravel-sized clasts. GeMS Sandstone Sedimentary rock, composed predominantly of particles or clasts derived by erosion and weathering of preexisting rock; consists mostly of sand-sized particles, with or without fine-grained matrix of silt or clay. GeMS Sedimentary material An aggregation of particles deposited by gravity, air, water, or ice, or as accumulated by other natural agents operating at Earths surface such as chemical precipitation or secretion by organisms. May include unconsolidated material (sediment) and (or) sedimentary rock. Does not include sedimentary material directly deposited as a result of volcanic activity. GeMS Debris flows, landslides, and other localized mass-movement sediment Sediment formed by relatively localized, downslope transport of particles or clasts produced by weathering and breakdown of underlying rock, sediment, and (or) soil. Composed of poorly sorted and poorly stratified material that ranges in size from clay to boulders. Speed of downslope transport ranges from rapid to imperceptible. GeMS Fine-grained intrusive igneous rock Rock that solidified from molten or partly molten material (magma) at shallow depth beneath Earths surface, thereby cooling quickly. Generally fine grained but may contain large mineral crystals (phenocrysts). Mostly found as tabular dikes or sills. GeMS Coastal zone sediment, mostly coarse-grained Mostly sand, silt, and gravel, deposited on beaches, in dunes, and in shallow-marine and related alluvial environments. GeMS Sandstone and mudstone Sandstone and mudstone (including shale and siltstone), in approximately equal (or unspecified) proportions. GeMS Limestone Carbonate sedimentary rock, consisting chiefly of calcite. GeMS Fine-grained, felsic-composition intrusive igneous rock Rock that solidified from molten or partly molten material (magma) at shallow depth beneath Earths surface, thereby cooling quickly. Generally fine grained but may contain large mineral crystals (phenocrysts). Mostly found as tabular dikes or sills. Composed mostly of light-colored minerals. Includes rhyolitic, dacitic, trachytic, and latitic rock. GeMS Clastic sediment Sediment formed by weathering and erosion of preexisting rocks or minerals; eroded particles or clasts are transported and deposited by gravity, air, water, or ice. GeMS Silt and clay of unspecified origin Sediment composed mostly of silt and (or) clay, formed by weathering and erosion of preexisting rocks or minerals; eroded particles or clasts are transported and deposited by gravity, air, water, or ice. GeMS Meta-ultramafic rock Rock derived from preexisting ultramafic rocks by essentially solid-state, mineralogical, chemical, or structural changes, in response to marked changes in temperature, pressure, deformation, and (or) chemical environment, generally at depth in Earths crust. Composed mostly of magnesium-bearing minerals (for example, serpentine, talc, magnesite). GeMS IndentedName Name with addition of leading spaces to help show rank within a hierarchical list. GeMS Unrepresentable domain Definition Plain-language definition. GeMS Unrepresentable domain DataSourcePolys Polygons that delineate data sources for all parts of the map. In the original file geodatabase, this dataset is found within the GeologicMap feature dataset. GeMS OBJECTID Internal feature number ESRI Unrepresentable domain Shape Internal geometry object ESRI Unrepresentable domain Shape_Length Internal feature length, double ESRI Unrepresentable domain Shape_Area Internal feature area, double ESRI Unrepresentable domain DataSourceID Source of data; foreign key to table DataSources. GeMS DASFRED100K035 Drake, A.A., Jr., Southworth, Scott, and Lee, K.Y., 1999, Geologic map of the Seneca quadrangle, Montgomery County, Maryland, and Fairfax and Loudoun Counties, Virginia: U.S. Geological Survey Geologic Quadrangle Map GQ–1802, scale 1:24,000. This report DASFRED100K051 Gathright, T.M., II, and Nystrom, P.G., Jr., 1974, Geology of the Ashby Gap quadrangle, Virginia: Virginia Division of Mineral Resources Report of Investigations 36, 55 p. This report DASFRED100K097 Southworth, Scott, 1995, Geologic map of the Purcellville quadrangle, Loudoun County, Virginia: U.S. Geological Survey Geologic Quadrangle Map GQ–1755, scale 1:24,000. This report DASFRED100K096 Southworth, Scott, 1994, Geologic map of the Bluemont quadrangle, Loudoun and Clarke Counties, Virginia: U.S. Geological Survey Geologic Quadrangle Map GQ–1739, scale 1:24,000. This report DASFRED100K019 | DASFRED100K014 DASFRED100K019 | DASFRED100K014 This report DASFRED100K102 Southworth, Scott, and Brezinski, D.K., 1996b, Geology of the Harpers Ferry quadrangle, Virginia, Maryland, and West Virginia: U.S. Geological Survey Bulletin 2123, 33 p., 1 pl. in pocket, scale 1:24,000. This report DASFRED100K003 This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. This report DASFRED100K019 Burton, W.C., Froelich, A.J., Pomeroy, J.S., and Lee, K.Y., 1995, Geology of the Waterford quadrangle, Virginia and Maryland, and the Virginia part of the Point of Rocks quadrangle: U.S. Geological Survey Bulletin 2095, 30 p., 1 pl. in pocket, scale 1:24,000. This report DASFRED100K026 Dean, S.L., Kulander, B.R., and Lessing, Peter, 1987, Geology of the Hedgesville, Keedysville, Martinsburg, Shepherdstown, and Williamsport quadrangles, Berkeley and Jefferson Counties, West Virginia: West Virginia Geological and Economic Survey Map WV–31, scale 1:24,000. This report DASFRED100K027 Dean, S.L., Lessing, Peter, and Kulander, B.R., 1990, Geology of the Berryville, Charles Town, Harpers Ferry, Middleway, and Round Hill quadrangles, Berkeley and Jefferson Counties, West Virginia: West Virginia Geological and Economic Survey Map WV–35, scale 1:24,000. This report DASFRED100K015 Brezinski, D.K., and Fauth, J.L., 2005, Geologic map of the Middletown quadrangle, Frederick and Washington Counties, Maryland: Baltimore, Maryland Geological Survey Digital Quadrangle Geologic Map, version MIDDLGEO2005.1, scale 1:24,000, 1 CD-ROM. This report DASFRED100K036 | DASFRED100K027 DASFRED100K036 | DASFRED100K027 This report DASFRED100K100 Southworth, Scott, 1999, Geologic map of the Urbana quadrangle, Frederick and Montgomery Counties, Maryland: U.S. Geological Survey Quadrangle GQ–1768, scale 1:24,000. This report DASFRED100K099 Southworth, Scott, 1998, Geologic map of the Poolesville quadrangle, Frederick and Montgomery Counties, Maryland and Loudoun County, Virginia: U.S. Geological Survey Geologic Quadrangle Map GQ–1761, 12 p. and 1:24,000- scale map. This report DASFRED100K031 Drake, A.A., Jr., 1998, Geologic map of the Kensington quadrangle, Montgomery County, Maryland: U.S. Geological Survey Geologic Quadrangle Map GQ–1774, scale 1:24,000. This report DASFRED100K017 Brezinski, D.K., Southworth, Scott, and Edwards, Jonathan, Jr., 2004, Geologic map of the Walkersville quadrangle: Baltimore, Maryland Geological Survey, scale 1:24,000. This report DASFRED100K103 Southworth, Scott, and Brezinski, D.K., 2003, Geologic map of the Buckeystown quadrangle, Frederick and Montgomery Counties, Maryland, and Loudoun County, Virginia: U.S. Geological Survey Geologic Quadrangle Map GQ–1800, scale 1:24,000. This report DASFRED100K080 McDowell, R.C., and Milton, D.J., 1992, Geologic map of the Round Hill quadrangle, Virginia and West Virginia: U.S. Geological Survey Geologic Quadrangle Map GQ–1702, scale 1:24,000. This report DASFRED100K013 Brezinski, D.K., 2004a, Geology of the Frederick quadrangle, Frederick County, Maryland: Baltimore, Maryland Geological Survey Digital Quadrangle Geologic Map, version FREDEGEO2004.1, scale 1:24,000, 1 CD-ROM. This report Notes Additional information specific to a particular feature or table entry. GeMS Unrepresentable domain. Free text. Values of <null> or #null indicate no entry. DataSourcePolys_ID Primary key. GeMS Arbitrary string. Values should be unique within this database. MapUnitOverlayPolys Polygons that delineate underlying material, overlying material, or some other aspect of earth materials that is described in table DescriptionOfMapUnits, e.g., dike swarm, colluvium. On a map graphic, such polygons are commonly shown by a patterned overprint. In the original file geodatabase, this dataset is found within the GeologicMap feature dataset. GeMS OBJECTID Internal feature number ESRI Unrepresentable domain Shape Internal geometry object ESRI Unrepresentable domain Shape_Length Internal feature length, double ESRI Unrepresentable domain Shape_Area Internal feature area, double ESRI Unrepresentable domain MapUnit Short plain-text identifier of the map unit. Foreign key to DescriptionOfMapUnits table. GeMS Qt Low level terrace deposit This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Qr Residuum This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. water Bodies of water. The boundaries of these features are located in the MapUnitOverlayLines feature class within this database. The location of these features is dictated by the base map originally used for publication. Users of this database should note that water boundaries vary through time and may not match current base maps and (or) lidar DASFRED100K003 QTt High level terrace deposit This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Qcf Fine colluvium This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Qa Alluvium This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Qcc Coarse colluvium This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ql Lag gravel This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. IdentityConfidence Confidence that feature is correctly identified. GeMS certain Identity of a feature can be determined using relevant observations and scientific judgment; therefore, one can be reasonably confident in the credibility of this interpretation Federal Geographic Data Committee [prepared for the Federal Geographic Data Committee by the U.S. Geological Survey], 2006, FGDC Digital Cartographic Standard for Geologic Map Symbolization: Reston, Va., Federal Geographic Data Committee Document Number FGDC-STD-013-2006, 290 p., 2 plates. Label Plain-text equivalent of the desired annotation for a feature: for example "14 Ma", or "^c" which (when used with the FGDC GeoAge font) results in the geologic map-unit label TRc (with TR run together to make the Triassic symbol). GeMS Unrepresentable domain Symbol Reference to a point marker, line symbol, or area-fill symbol that is used on the map graphic to denote the feature: perhaps a star for a K-Ar age locality, or a heavy black line for a fault. GeMS Unrepresentable domain DataSourceID Source of data; foreign key to table DataSources. GeMS DASFRED100K003 This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. This report Notes Additional information specific to a particular feature or table entry. GeMS Unrepresentable domain. Free text. Values of <null> or #null indicate no entry. MapUnitOverlayPolys_ID Primary key. GeMS Arbitrary string. Values should be unique within this database. Pattern These are the FGDC patterns from the FGDC geologic map symbolization document. They match the patterns to the closest approximate pattern used on the original geologic map. The patterns used in the original publication predate the FGDC geologic map symbolization document and will not match perfectly DASFRED100K003 Unrepresentable domain ContactsAndFaults Contacts between map units, faults that bound map units, and associated dangling faults. Includes concealed faults and contacts, waterlines, snowfield and glacier boundaries, and map boundary. In the original file geodatabase, this dataset is found within the GeologicMap feature dataset. GeMS OBJECTID Internal feature number ESRI Unrepresentable domain Shape Internal geometry object ESRI Unrepresentable domain Shape_Length Internal feature length, double ESRI Unrepresentable domain Type Classifier that specifies what kind of geologic feature is represented by a database element: that a certain line within feature class ContactsAndFaults is a contact, or thrust fault, or water boundary; or that a point in GeochronPoints represents a K-Ar date. GeMS fault, unclassified A discrete surface or zone of discrete surfaces separating two rock masses across which one mass has slid past the other in an undefined way. Dotted where concealed by water and (or) surficial materials Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2011, Glossary of geology (5th ed., revised): Alexandria, Va., American Geosciences Institute, 783 p. neat line The project boundary of the map as shown in the "ContactsandFaults" feature class This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. fault, thrust A discrete surface or zone of discrete surfaces separating two rock masses, one a hanging wall, and one a footwall, in which the hanging wall has moved upward relative to the footwall. Dotted where concealed by water and (or) surficial materials. All faults in this database are considered approximate Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2011, Glossary of geology (5th ed., revised): Alexandria, Va., American Geosciences Institute, 783 p. fault, normal A discrete surface or zone of discrete surfaces separating two rock masses, one a hanging wall, and one a footwall, in which the hanging wall has moved downward relative to the footwall. Dotted where concealed by water and (or) surficial materials. All faults in this database are considered approximate Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2011, Glossary of geology (5th ed., revised): Alexandria, Va., American Geosciences Institute, 783 p. fault, reactivated A discrete surface or zone of discrete surfaces separating two rock masses, one a hanging wall, and one a footwall, in which the hanging wall has moved downward relative to the footwall. At a later time this surface was reactivated as a thrust fault in which the hanging wall has moved upward relative to the footwall. Shown in cross section as a double-headed arrow on the published geologic map. Dotted where concealed by water and (or) surficial materials. All faults in this database are considered approximate AGI | DASFRED100K003 contact Trace of a plane or irregular surface between two types or ages of rock. Dotted where concealed by water and (or) surficial materials. All contacts in this database are considered approximate Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2011, Glossary of geology (5th ed., revised): Alexandria, Va., American Geosciences Institute, 783 p. fault, overturned thrust A overturned (likely due to folding) discrete surface or zone of discrete surfaces separating two rock masses, one a hanging wall, and one a footwall, in which the hanging wall has moved upward relative to the footwall. Dotted where concealed by water and (or) surficial materials. All faults in this database are considered approximate Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2011, Glossary of geology (5th ed., revised): Alexandria, Va., American Geosciences Institute, 783 p. fault, strike-slip A discrete surface or zone of discrete surfaces separating two rock masses across in which one mass has slid past the other in a left-lateral or right-lateral direction. The leftward and rightward movement is defined by the FGDC reference value found within the symbol field for this feature. Dotted where concealed by water and (or) surficial materials. All faults in this database are considered approximate AGI | DASFRED100K003 IsConcealed Flag for contacts and faults covered by overlying map unit. GeMS Unrepresentable domain LocationConfidenceMeters Estimated half-width in meters of positional uncertainty envelope; position is relative to other features in database. GeMS Positive real number. Value of -9, -99, or -999 indicates value is unknown. ExistenceConfidence Confidence that feature exists. GeMS certain Identity of a feature can be determined using relevant observations and scientific judgment; therefore, one can be reasonably confident in the credibility of this interpretation Federal Geographic Data Committee [prepared for the Federal Geographic Data Committee by the U.S. Geological Survey], 2006, FGDC Digital Cartographic Standard for Geologic Map Symbolization: Reston, Va., Federal Geographic Data Committee Document Number FGDC-STD-013-2006, 290 p., 2 plates. questionable Identity of a feature cannot be determined using relevant observations and scientific judgment; therefore, one cannot be reasonably confident in the credibility of this interpretation. For example, IdentityConfidence = questionable is appropriate when a geologist reasons "I can see some kind of planar feature that separates map units in this outcrop, but I cannot be certain if it is a contact or a fault" Federal Geographic Data Committee [prepared for the Federal Geographic Data Committee by the U.S. Geological Survey], 2006, FGDC Digital Cartographic Standard for Geologic Map Symbolization: Reston, Va., Federal Geographic Data Committee Document Number FGDC-STD-013-2006, 290 p., 2 plates. IdentityConfidence Confidence that feature is correctly identified. GeMS certain Identity of a feature can be determined using relevant observations and scientific judgment; therefore, one can be reasonably confident in the credibility of this interpretation Federal Geographic Data Committee [prepared for the Federal Geographic Data Committee by the U.S. Geological Survey], 2006, FGDC Digital Cartographic Standard for Geologic Map Symbolization: Reston, Va., Federal Geographic Data Committee Document Number FGDC-STD-013-2006, 290 p., 2 plates. questionable Identity of a feature cannot be determined using relevant observations and scientific judgment; therefore, one cannot be reasonably confident in the credibility of this interpretation. For example, IdentityConfidence = questionable is appropriate when a geologist reasons "I can see some kind of planar feature that separates map units in this outcrop, but I cannot be certain if it is a contact or a fault" Federal Geographic Data Committee [prepared for the Federal Geographic Data Committee by the U.S. Geological Survey], 2006, FGDC Digital Cartographic Standard for Geologic Map Symbolization: Reston, Va., Federal Geographic Data Committee Document Number FGDC-STD-013-2006, 290 p., 2 plates. Label Plain-text equivalent of the desired annotation for a feature: for example "14 Ma", or "^c" which (when used with the FGDC GeoAge font) results in the geologic map-unit label TRc (with TR run together to make the Triassic symbol). GeMS Unrepresentable domain Symbol Reference to a point marker, line symbol, or area-fill symbol that is used on the map graphic to denote the feature: perhaps a star for a K-Ar age locality, or a heavy black line for a fault. GeMS Unrepresentable domain DataSourceID Source of data; foreign key to table DataSources. GeMS DASFRED100K003 This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. This report Notes Additional information specific to a particular feature or table entry. GeMS Unrepresentable domain. Free text. Values of <null> or #null indicate no entry. ContactsAndFaults_ID Primary key. GeMS Arbitrary string. Values should be unique within this database. GeologicLines Lines that represent dikes, coal seams, ash beds, fold hinge-surface traces, isograds, and other linear features. All have these properties: (A) They do not participate in map-unit topology. (B) They correspond to features that exist within the Earth and may be concealed beneath younger, covering, material. (C) They are located with an accuracy that likely can be estimated. In the original file geodatabase, this dataset is found within the GeologicMap feature dataset. GeMS OBJECTID Internal feature number ESRI Unrepresentable domain Shape Internal geometry object ESRI Unrepresentable domain Shape_Length Internal feature length, double ESRI Unrepresentable domain Type Classifier that specifies what kind of geologic feature is represented by a database element: that a certain line within feature class ContactsAndFaults is a contact, or thrust fault, or water boundary; or that a point in GeochronPoints represents a K-Ar date. GeMS lake bed Lines indicating the location of lake boundaries formed during the rifting of the Atlantic ocean during the Mesozoic era. Dotted where concealed by water and (or) surficial materials. All values in this database are considered approximate This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. IsConcealed Flag for contacts and faults covered by overlying map unit. GeMS Unrepresentable domain LocationConfidenceMeters Estimated half-width in meters of positional uncertainty envelope; position is relative to other features in database. GeMS Positive real number. Value of -9, -99, or -999 indicates value is unknown. ExistenceConfidence Confidence that feature exists. GeMS certain Identity of a feature can be determined using relevant observations and scientific judgment; therefore, one can be reasonably confident in the credibility of this interpretation Federal Geographic Data Committee [prepared for the Federal Geographic Data Committee by the U.S. Geological Survey], 2006, FGDC Digital Cartographic Standard for Geologic Map Symbolization: Reston, Va., Federal Geographic Data Committee Document Number FGDC-STD-013-2006, 290 p., 2 plates. IdentityConfidence Confidence that feature is correctly identified. GeMS certain Identity of a feature can be determined using relevant observations and scientific judgment; therefore, one can be reasonably confident in the credibility of this interpretation Federal Geographic Data Committee [prepared for the Federal Geographic Data Committee by the U.S. Geological Survey], 2006, FGDC Digital Cartographic Standard for Geologic Map Symbolization: Reston, Va., Federal Geographic Data Committee Document Number FGDC-STD-013-2006, 290 p., 2 plates. Symbol Reference to a point marker, line symbol, or area-fill symbol that is used on the map graphic to denote the feature: perhaps a star for a K-Ar age locality, or a heavy black line for a fault. GeMS Unrepresentable domain Label Plain-text equivalent of the desired annotation for a feature: for example "14 Ma", or "^c" which (when used with the FGDC GeoAge font) results in the geologic map-unit label TRc (with TR run together to make the Triassic symbol). GeMS Unrepresentable domain DataSourceID Source of data; foreign key to table DataSources. GeMS DASFRED100K003 This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. This report Notes Additional information specific to a particular feature or table entry. GeMS Unrepresentable domain. Free text. Values of <null> or #null indicate no entry. GeologicLines_ID Primary key. GeMS Arbitrary string. Values should be unique within this database. CartographicLines Lines (e.g., cross-section lines) that have no real-world physical existence, such that LocationConfidenceMeters, ExistenceConfidence, and IdentityConfidence attributes are meaningless, and that are never shown as concealed beneath a covering unit. In the original file geodatabase, this dataset is found within the GeologicMap feature dataset. GeMS OBJECTID Internal feature number ESRI Unrepresentable domain Shape Internal geometry object ESRI Unrepresentable domain Shape_Length Internal feature length, double ESRI Unrepresentable domain Type Classifier that specifies what kind of geologic feature is represented by a database element: that a certain line within feature class ContactsAndFaults is a contact, or thrust fault, or water boundary; or that a point in GeochronPoints represents a K-Ar date. GeMS cross section line Surface line used to diagram or drawing that shows features transected by a given plane Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2011, Glossary of geology (5th ed., revised): Alexandria, Va., American Geosciences Institute, 783 p. Symbol Reference to a point marker, line symbol, or area-fill symbol that is used on the map graphic to denote the feature: perhaps a star for a K-Ar age locality, or a heavy black line for a fault. GeMS Unrepresentable domain Label Plain-text equivalent of the desired annotation for a feature: for example "14 Ma", or "^c" which (when used with the FGDC GeoAge font) results in the geologic map-unit label TRc (with TR run together to make the Triassic symbol). GeMS Unrepresentable domain DataSourceID Source of data; foreign key to table DataSources. GeMS DASFRED100K003 This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. This report Notes Additional information specific to a particular feature or table entry. GeMS Unrepresentable domain. Free text. Values of <null> or #null indicate no entry. CartographicLines_ID Primary key. GeMS Arbitrary string. Values should be unique within this database. MapUnitLines Lines that record distribution of map units of narrow, linear extent on the particular map horizon. In the original file geodatabase, this dataset is found within the GeologicMap feature dataset. GeMS OBJECTID Internal feature number ESRI Unrepresentable domain Shape Internal geometry object ESRI Unrepresentable domain Shape_Length Internal feature length, double ESRI Unrepresentable domain MapUnit Short plain-text identifier of the map unit. Foreign key to DescriptionOfMapUnits table. GeMS Zmd Metadiabase dike This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. IsConcealed Flag for contacts and faults covered by overlying map unit. GeMS Unrepresentable domain LocationConfidenceMeters Estimated half-width in meters of positional uncertainty envelope; position is relative to other features in database. GeMS Positive real number. Value of -9, -99, or -999 indicates value is unknown. ExistenceConfidence Confidence that feature exists. GeMS certain Identity of a feature can be determined using relevant observations and scientific judgment; therefore, one can be reasonably confident in the credibility of this interpretation Federal Geographic Data Committee [prepared for the Federal Geographic Data Committee by the U.S. Geological Survey], 2006, FGDC Digital Cartographic Standard for Geologic Map Symbolization: Reston, Va., Federal Geographic Data Committee Document Number FGDC-STD-013-2006, 290 p., 2 plates. IdentityConfidence Confidence that feature is correctly identified. GeMS certain Identity of a feature can be determined using relevant observations and scientific judgment; therefore, one can be reasonably confident in the credibility of this interpretation Federal Geographic Data Committee [prepared for the Federal Geographic Data Committee by the U.S. Geological Survey], 2006, FGDC Digital Cartographic Standard for Geologic Map Symbolization: Reston, Va., Federal Geographic Data Committee Document Number FGDC-STD-013-2006, 290 p., 2 plates. Label Plain-text equivalent of the desired annotation for a feature: for example "14 Ma", or "^c" which (when used with the FGDC GeoAge font) results in the geologic map-unit label TRc (with TR run together to make the Triassic symbol). GeMS Unrepresentable domain Symbol Reference to a point marker, line symbol, or area-fill symbol that is used on the map graphic to denote the feature: perhaps a star for a K-Ar age locality, or a heavy black line for a fault. GeMS Unrepresentable domain PlotAtScale At what scale (or larger) should this observation or analysis be plotted? At smaller scales, it should not be plotted. Useful to prevent crowding of display at small scales and to display progressively more data at larger and larger scales. Value is scale denominator. GeMS Positive real number. DataSourceID Source of data; foreign key to table DataSources. GeMS DASFRED100K003 This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. This report Notes Additional information specific to a particular feature or table entry. GeMS Unrepresentable domain. Free text. Values of <null> or #null indicate no entry. MapUnitLines_ID Primary key. GeMS Arbitrary string. Values should be unique within this database. OrientationPoints Point structure data (e.g., bedding attitudes, foliation attitudes, slip vectors measured at a point, etc.), one point per measurement. Multiple measurements at a single station (e.g., bedding and cleavage) should have the same StationsID. In the original file geodatabase, this dataset is found within the GeologicMap feature dataset. GeMS OBJECTID Internal feature number ESRI Unrepresentable domain Shape Internal geometry object ESRI Unrepresentable domain Type Classifier that specifies what kind of geologic feature is represented by a database element: that a certain line within feature class ContactsAndFaults is a contact, or thrust fault, or water boundary; or that a point in GeochronPoints represents a K-Ar date. GeMS cleavage, S2 A structural measurement of a second-generation (S2) Paleozoic cleavage and (or) schistosity in an unmetamorphosed or weakly metamorphosed, fine-grained rock defined by either the tendency of a rock to split in a particular direction, a preferred orientation of crystal planes in mineral grains, or a preferred orientation of inequant grain shapes; it is a product of deformation or metamorphism AGI | DASFRED100K003 foliation, Mesoproterozoic Structural measurement of a planar arrangement of textural or structural features in any type of rock, especially the locally planar fabric in a rock defined by a fissility, a preferred orientation of crystal planes in mineral grains, a preferred orientation of inequant grain shapes, or from compositional banding that occured during the Mesoproterozoic era AGI | DASFRED100K003 bedding A structural measurement of a layer of sediments or sedimentary rocks bounded above and below by more or less well-defined bedding surfaces. This feature may contain inclined, overturned, horizontal, or vertical bedding as indicated by the FGDC reference number contained in the "Symbol" field associated with that measurement AGI | DASFRED100K003 fold axis A structural measurement of a line which, when moved parallel to itself, traces out a folded surface Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2011, Glossary of geology (5th ed., revised): Alexandria, Va., American Geosciences Institute, 783 p. foliation, mylonitic and phyllonitic Structural measurement of a planar arrangement of textural or structural features in mylonitic or phyllonitic rock AGI | DASFRED100K003 foliation, S1 Structural measurement of a planar arrangement of textural or structural features in any type of rock, especially the locally planar fabric in a rock defined by a fissility, a preferred orientation of crystal planes in mineral grains, a preferred orientation of inequant grain shapes, or from compositional banding that occured during the Paleozoic era AGI | DASFRED100K003 Azimuth Strike or trend, measured in degrees clockwise from geographic North. Use right-hand rule (dip is to right of azimuth direction). Horizontal planar features may have any azimuth. GeMS 0 360 degrees (angular measure) Inclination Dip or plunge, measured in degrees down from horizontal. Negative values allowed when specifying vectors (not axes) that point above the horizon, e.g., paleocurrents. Types defined as horizontal (e.g., horizontal bedding) shall have Inclination=0. GeMS -90 90 degrees (angular measure) Symbol Reference to a point marker, line symbol, or area-fill symbol that is used on the map graphic to denote the feature: perhaps a star for a K-Ar age locality, or a heavy black line for a fault. GeMS Unrepresentable domain Label Plain-text equivalent of the desired annotation for a feature: for example "14 Ma", or "^c" which (when used with the FGDC GeoAge font) results in the geologic map-unit label TRc (with TR run together to make the Triassic symbol). GeMS Unrepresentable domain LocationConfidenceMeters Estimated half-width in meters of positional uncertainty envelope; position is relative to other features in database. GeMS Positive real number. Value of -9, -99, or -999 indicates value is unknown. IdentityConfidence Confidence that feature is correctly identified. GeMS certain Identity of a feature can be determined using relevant observations and scientific judgment; therefore, one can be reasonably confident in the credibility of this interpretation Federal Geographic Data Committee [prepared for the Federal Geographic Data Committee by the U.S. Geological Survey], 2006, FGDC Digital Cartographic Standard for Geologic Map Symbolization: Reston, Va., Federal Geographic Data Committee Document Number FGDC-STD-013-2006, 290 p., 2 plates. questionable Identity of a feature cannot be determined using relevant observations and scientific judgment; therefore, one cannot be reasonably confident in the credibility of this interpretation. For example, IdentityConfidence = questionable is appropriate when a geologist reasons "I can see some kind of planar feature that separates map units in this outcrop, but I cannot be certain if it is a contact or a fault" Federal Geographic Data Committee [prepared for the Federal Geographic Data Committee by the U.S. Geological Survey], 2006, FGDC Digital Cartographic Standard for Geologic Map Symbolization: Reston, Va., Federal Geographic Data Committee Document Number FGDC-STD-013-2006, 290 p., 2 plates. OrientationConfidenceDegrees Estimated angular precision of combined azimuth AND inclination measurements, in degrees. GeMS Positive real number. Value of -9, -99, or -999 indicates value is unknown. PlotAtScale At what scale (or larger) should this observation or analysis be plotted? At smaller scales, it should not be plotted. Useful to prevent crowding of display at small scales and to display progressively more data at larger and larger scales. Value is scale denominator. GeMS Positive real number. StationsID Foreign key to Stations point feature class. GeMS Unrepresentable domain MapUnit Short plain-text identifier of the map unit. Foreign key to DescriptionOfMapUnits table. GeMS Csql Lower member of the Sugarloaf Mountain Quartzite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ccwm Maryland Heights Member of the Weverton Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ccw Undivided rocks of the Weverton Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Obs Upper part of the Stonehenge Limestone This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cfl Lime Kiln Member of the Frederick Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cclc Conglomerate of the Loudoun Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ylg Layered granitic gneiss This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Csqu Upper member of the Sugarloaf Mountain Quartzite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cfa Adamstown Member of the Frederick Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZsc Calcareous metasandstone of the Sams Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZl Loch Raven Schist This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ctd Dargan Member of the Tomstown Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cu Urbana Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cfrs Shale of the Rocky Springs Station Member of the Frederick Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Jmt Turkey Run Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Zfsm Metamudstone of the Swains Mountain Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cs Sykesville Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZpb Metabasalt of the Prettyboy Schist This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ct Tomstown Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cum Marble of the Urbana Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Yc Charnockitic granite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ok Kensington Tonalite DASFRED100K055 | DASFRED100K047 CZu Mafic and ultramafic rocks This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Om Martinsburg Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cl Laurel Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZib Metabasalt of the Ijamsville Phyllite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Csqm Middle member of the Sugarloaf Mountain Quartzite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cf Undivided rocks of the Frederick Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Yqp Quartz-plagioclase gneiss This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Oq Quartz bodies This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZicp Chloritic phyllite of the Ijamsville Phyllite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Obrr Rockdale Run Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Zcm Metabasalt of the Catoctin Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cca Antietam Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZmbq Quartzite of the Marburg Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Zsp Phyllite of the Swift Run Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ym Marshall Metagranite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cclp Phyllite of the Loudoun Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ccb Big Spring Station Member of the Conococheague Limestone This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Zfsc Boulder conglomerate of the Swains Mountain Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Zrd Metarhyolite dike This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Zsm Marble of the Swift Run Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cuq Quartzite of the Urbana Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZip Phyllite of the Ijamsville Phyllite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ygt Garnetiferous metagranite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZmp Phyllonite of the Mather Gorge Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Zcp Tuffaceous phyllite of the Catoctin Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Jmh Hickory Grove Basalt This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZn Northwest Branch Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ogg Quartz gabbro of the Georgetown Intrusive Suite Fleming, A.H., Drake, A.A., Jr., and McCartan, Lucy, 1994, Geologic map of the Washington West quadrangle, District of Columbia, Montgomery and Prince Georges Counties, Maryland, and Arlington and Fairfax Counties, Virginia: U.S. Geological Survey Geologic Quadrangle Map GQ– 1748, scale 1:24,000. CZsb Metabasalt of the Sams Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Trcbl Leesburg Member of the Bull Run Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZsm Marble of the Sams Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ogh Biotite-hornblende tonalite of the Georgetown Intrusive Suite DASFRED100K033 | DASFRED100K047 CZp Prettyboy Schist This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cwac Chewsville Member of the Waynesboro Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. OCgu Upper Member of the Grove Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Trcbb Balls Bluff Member of the Bull Run Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Zss Metasandstone and schist of the Swift Run Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Yp Garnet-graphite paragneiss This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cwact Cavetown Member of the Waynesboro Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Trcmp Poolesville Member of the Manassas Sandstone This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZmg Metagraywacke of the Mather Gorge Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZiq Quartzite of the Ijamsville Phyllite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Zmd Metadiabase dike This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZshp Hematitic phyllite of the Sams Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Car Araby Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZlm Semipelitic schist and meta-arenite of the Loch Raven Schist This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZsq Quartzite of the Sams Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ctf Fort Duncan Member of the Tomstown Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cwar Red Run Member of the Waynesboro Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Zcr Metarhyolite of the Catoctin Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Zcma Marble of the Catoctin Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZil Metalimestone of the Ijamsville Phyllite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Yg White leucocratic metagranite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cchs Metasandstone of the Harpers Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZmbg Metagraywacke of the Marburg Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ce Elbrook Limestone This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ypg Porphyroblastic metagranite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ccwb Buzzard Knob Member of the Weverton Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ont Biotite-hornblende tonalite of the Norbeck Intrusive Suite Hopson, C.A., 1964, The crystalline rocks of Howard and Montgomery Counties, Md., in The geology of Howard and Montgomery Counties: Baltimore, Maryland Geological Survey, p. 27–215. CZsl Metalimestone of the Sams Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Obps Pinesburg Station Dolomite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZms Quartz-rich schist of the Mather Gorge Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Yhm Hornblende monzonite gneiss This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ya Amphibolite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ccwo Owens Creek Member of the Weverton Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. JTrcc Catharpin Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZsmp Muscovitic phyllite of the Sams Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Yq Quartzite and quartz-sericite tectonite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cch Harpers Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ctb Benevola Member of the Tomstown Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Trcmt Tuscarora Creek Member of the Manassas Sandstone This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZsd Soldiers Delight Ultramafite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZsqp Quartzite interbedded with phyllite of the Sams Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. OCgl Lower Member of the Grove Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZss Metasiltstone of the Sams Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Oc Chambersburg Limestone This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. JTrccg Goose Creek Member of the Catharpin Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ymc Coarse-grained metagranite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZstp Tuffaceous phyllite of the Sams Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ybg Biotite granite gneiss This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Osnr New Market and Row Park Limestones undivided, of the St. Paul Group This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ctbh Bolivar Heights Member of the Tomstown Formation Brezinski, D.K., 1996, Stratigraphy of the Elbrook Formation (Middle to Upper Cambrian) in Maryland and adjacent States, in Brezinski, D.K., and J.P. Reger, eds., Studies in Maryland geology: Maryland Geological Survey Special Publication 3, p. 165–186. CZmm Migmatite of the Mather Gorge Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZmbs Metasiltstone of the Marburg Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. OCc Conococheague Limestone This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Clu Upper part of the Laurel Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Trcmr Reston Member of the Manassas Sandstone This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cfr Rocky Springs Station Member of the Frederick Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Yml Pink leucocratic metagranite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ct* Tomstown Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Trcbg Groveton member of the Bull Run Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Obss Stoufferstown Member of the Stonehenge Limestone This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. LocationSourceID Source of location; foreign key to table DataSources. GeMS DASFRED100K003 This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. This report OrientationSourceID Source of orientation data; foreign key to table DataSources. GeMS DASFRED100K003 This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. This report Notes Additional information specific to a particular feature or table entry. GeMS Unrepresentable domain. Free text. Values of <null> or #null indicate no entry. OrientationPoints_ID Primary key. GeMS Arbitrary string. Values should be unique within this database. GeochronPoints Point locations of samples and accompanying geochronological measurements. Type field identifies geochronological method. In the original file geodatabase, this dataset is found within the GeologicMap feature dataset. GeMS OBJECTID Internal feature number ESRI Unrepresentable domain Shape Internal geometry object ESRI Unrepresentable domain Type Classifier that specifies what kind of geologic feature is represented by a database element: that a certain line within feature class ContactsAndFaults is a contact, or thrust fault, or water boundary; or that a point in GeochronPoints represents a K-Ar date. GeMS U-Pb age locality Location of isotopically dated calculation of an age in years for geologic material based on the known radioactive decay rate of uranium-238 to lead-206 and uranium-235 to lead-207 Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2011, Glossary of geology (5th ed., revised): Alexandria, Va., American Geosciences Institute, 783 p. FieldSampleID Sample ID given at time of collection. GeMS Unrepresentable domain AlternateSampleID Museum #, lab #, etc. GeMS Unrepresentable domain MapUnit Short plain-text identifier of the map unit. Foreign key to DescriptionOfMapUnits table. GeMS Zrd Metarhyolite dike This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ygt Garnetiferous metagranite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Yhm Hornblende monzonite gneiss This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ymc Coarse-grained metagranite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Yg White leucocratic metagranite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Yc Charnockitic granite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ybg Biotite granite gneiss This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Symbol Reference to a point marker, line symbol, or area-fill symbol that is used on the map graphic to denote the feature: perhaps a star for a K-Ar age locality, or a heavy black line for a fault. GeMS Unrepresentable domain Label Plain-text equivalent of the desired annotation for a feature: for example "14 Ma", or "^c" which (when used with the FGDC GeoAge font) results in the geologic map-unit label TRc (with TR run together to make the Triassic symbol). GeMS Unrepresentable domain LocationConfidenceMeters Estimated half-width in meters of positional uncertainty envelope; position is relative to other features in database. GeMS Positive real number. Value of -9, -99, or -999 indicates value is unknown. PlotAtScale At what scale (or larger) should this observation or analysis be plotted? At smaller scales, it should not be plotted. Useful to prevent crowding of display at small scales and to display progressively more data at larger and larger scales. Value is scale denominator. GeMS Positive real number. MaterialAnalyzed Earth-material which was analyzed, e.g., wood, shell, zircon, basalt, whole-rock. GeMS Unrepresentable domain NumericAge Age of map unit as shown in Description of Map Units. Examples of values are "late Holocene", "Pliocene and Miocene", "Lower Cretaceous". GeMS Unrepresentable domain AgePlusError Positive (older) age error, measured in AgeUnits. Type of error (RMSE, 1 sigma, 2 sigma, 95% confidence limit) should be stated in Notes field. GeMS Positive real number. Value of -9, -99, or -999 indicates value is unknown. AgeMinusError Negative (younger) age error, measured in AgeUnits. Type of error (RMSE, 1 sigma, 2 sigma, 95% confidence limit) should be stated in Notes field. GeMS Positive real number. Value of -9, -99, or -999 indicates value is unknown. ErrorMeasure Measure of error whose values are recorded in AgePlusError and AgeMinusError fields GeMS Unrepresentable domain AgeUnits Units for NumericAge, AgePlusError, AgeMinusError. GeMS Ma Mega-annum (millions of years) Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2011, Glossary of geology (5th ed., revised): Alexandria, Va., American Geosciences Institute, 783 p. StationsID Foreign key to Stations point feature class. GeMS Unrepresentable domain LocationSourceID Source of location; foreign key to table DataSources. GeMS DASFRED100K003 This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. This report AnalysisSourceID Source of analysis; foreign key to table DataSources. GeMS DASFRED100K005 Aleinikoff, J.N., Burton, W.C., Lyttle, P.T., Nelson, A.E., and Southworth, C.S., 2000, U-Pb geochronology of zircon and monazite from Mesoproterozoic granitic gneisses of the northern Blue Ridge, Virginia and Maryland: Precambrian Research, v. 99, nos. 1–2, p. 113–146. This report DASFRED100K004 Aleinikoff, J.N., Zartman, R.E., Walter, Marianne, Rankin, D.W., Lyttle, P.T., and Burton, W.C., 1995, U-Pb ages of metarhyolites of the Catoctin and Mount Rogers Formations, central and southern Appalachians; Evidence for two pulses of Iapetan rifting: American Journal of Science, v. 295, no. 4, p. 428–454. This report Notes Additional information specific to a particular feature or table entry. GeMS Unrepresentable domain. Free text. Values of <null> or #null indicate no entry. GeochronPoints_ID Primary key. GeMS Arbitrary string. Values should be unique within this database. GenericPoints Feature class for the mineral resources and additional point information as identified on the published geologic map DASFRED100K003 OBJECTID Internal feature number ESRI Unrepresentable domain Shape Internal geometry object ESRI Unrepresentable domain Type Classifier that specifies what kind of geologic feature is represented by a database element: that a certain line within feature class ContactsAndFaults is a contact, or thrust fault, or water boundary; or that a point in GeochronPoints represents a K-Ar date. GeMS radon Measurement locations of radon in soil gas—Shown where greater than 200 pCi/L (Gunderson and others, 1988) Gunderson, L.C.S., Reimer, G.M., Wiggs, C.R., and Rice, C.A., 1988, Map showing radon potential of rocks and soils in Montgomery County, Maryland: U.S. Geological Survey Miscellaneous Field Studies Map MF–2043, scale 1:62,500. mine or quarry An underground and surficial excavation for the extraction of mineral deposits and (or) building materials. The terms also apply to various types of open-pit workings. Abbreviations [in the "Label" field] are as follows: Ag, silver; Au, gold; C, chromite; Cu, copper; D, diabase; F, hematite, limonite, manganese, and iron ore; L, limestone; M, marble; Pb, lead; S, building stone; Sl, slate; Zn, zinc AGI | DASFRED100K003 sinkhole A closed depression in a karst or pseudokarst area, commonly with a circular or ellipsoidal pattern. Sinkhole locations with a value of less than or equal to 50 m2 in diameter are located within the "GenericPoints" feature class. Sinkholes greater than 50m2 in diameter are located in the "OverlayPolys" feature class AGI | DASFRED100K003 Symbol Reference to a point marker, line symbol, or area-fill symbol that is used on the map graphic to denote the feature: perhaps a star for a K-Ar age locality, or a heavy black line for a fault. GeMS Unrepresentable domain Label Plain-text equivalent of the desired annotation for a feature: for example "14 Ma", or "^c" which (when used with the FGDC GeoAge font) results in the geologic map-unit label TRc (with TR run together to make the Triassic symbol). GeMS Unrepresentable domain LocationConfidenceMeters Estimated half-width in meters of positional uncertainty envelope; position is relative to other features in database. GeMS Positive real number. Value of -9, -99, or -999 indicates value is unknown. PlotAtScale At what scale (or larger) should this observation or analysis be plotted? At smaller scales, it should not be plotted. Useful to prevent crowding of display at small scales and to display progressively more data at larger and larger scales. Value is scale denominator. GeMS Positive real number. StationsID Foreign key to Stations point feature class. GeMS Unrepresentable domain MapUnit Short plain-text identifier of the map unit. Foreign key to DescriptionOfMapUnits table. GeMS Ccwm Maryland Heights Member of the Weverton Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZmg Metagraywacke of the Mather Gorge Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cch Harpers Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Obrr Rockdale Run Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ctb Benevola Member of the Tomstown Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Zcm Metabasalt of the Catoctin Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Obs Upper part of the Stonehenge Limestone This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cfl Lime Kiln Member of the Frederick Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Car Araby Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cca Antietam Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Zsp Phyllite of the Swift Run Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ym Marshall Metagranite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZsqp Quartzite interbedded with phyllite of the Sams Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ccb Big Spring Station Member of the Conococheague Limestone This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Csqu Upper member of the Sugarloaf Mountain Quartzite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cfa Adamstown Member of the Frederick Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. OCgl Lower Member of the Grove Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ctf Fort Duncan Member of the Tomstown Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ctd Dargan Member of the Tomstown Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cuq Quartzite of the Urbana Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZl Loch Raven Schist This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Oc Chambersburg Limestone This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZip Phyllite of the Ijamsville Phyllite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cwar Red Run Member of the Waynesboro Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZw Wakefield Marble This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Zcma Marble of the Catoctin Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZstp Tuffaceous phyllite of the Sams Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cs Sykesville Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Osnr New Market and Row Park Limestones undivided, of the St. Paul Group This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ct Tomstown Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ctbh Bolivar Heights Member of the Tomstown Formation Brezinski, D.K., 1996, Stratigraphy of the Elbrook Formation (Middle to Upper Cambrian) in Maryland and adjacent States, in Brezinski, D.K., and J.P. Reger, eds., Studies in Maryland geology: Maryland Geological Survey Special Publication 3, p. 165–186. CZmm Migmatite of the Mather Gorge Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZmbs Metasiltstone of the Marburg Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Jmh Hickory Grove Basalt This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ce Elbrook Limestone This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZmp Phyllonite of the Mather Gorge Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. OCc Conococheague Limestone This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZsb Metabasalt of the Sams Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ont Biotite-hornblende tonalite of the Norbeck Intrusive Suite Hopson, C.A., 1964, The crystalline rocks of Howard and Montgomery Counties, Md., in The geology of Howard and Montgomery Counties: Baltimore, Maryland Geological Survey, p. 27–215. Ok Kensington Tonalite DASFRED100K055 | DASFRED100K047 Trcbl Leesburg Member of the Bull Run Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Om Martinsburg Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZu Mafic and ultramafic rocks This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Jdh High-titanium quartz-normative late cumulates This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZsm Marble of the Sams Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZsl Metalimestone of the Sams Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Obps Pinesburg Station Dolomite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cwac Chewsville Member of the Waynesboro Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. OCgu Upper Member of the Grove Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cfr Rocky Springs Station Member of the Frederick Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZms Quartz-rich schist of the Mather Gorge Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Trcbb Balls Bluff Member of the Bull Run Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ct* Tomstown Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Jd Crystalline diabase This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cwact Cavetown Member of the Waynesboro Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Trcmp Poolesville Member of the Manassas Sandstone This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. JTrcc Catharpin Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZsmp Muscovitic phyllite of the Sams Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Obss Stoufferstown Member of the Stonehenge Limestone This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. LocationSourceID Source of location; foreign key to table DataSources. GeMS DASFRED100K003 This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. This report DataSourceID Source of data; foreign key to table DataSources. GeMS DASFRED100K003 This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. This report Notes Additional information specific to a particular feature or table entry. GeMS Unrepresentable domain. Free text. Values of <null> or #null indicate no entry. GenericPoints_ID Primary key. GeMS Arbitrary string. Values should be unique within this database. MapUnitOverlayLines Surficial contacts and water contacts for the published geologic map. These boundaries correspond to the polygons in the MapOverlayUnitPolys feature class. DASFRED100K003 OBJECTID Internal feature number ESRI Unrepresentable domain Shape Internal geometry object ESRI Unrepresentable domain Type Classifier that specifies what kind of geologic feature is represented by a database element: that a certain line within feature class ContactsAndFaults is a contact, or thrust fault, or water boundary; or that a point in GeochronPoints represents a K-Ar date. GeMS contact Trace of a plane or irregular surface between two types or ages of rock. Dotted where concealed by water and (or) surficial materials. All contacts in this database are considered approximate Neuendorf, K.K.E., Mehl, J.P., Jr., and Jackson, J.A., eds., 2011, Glossary of geology (5th ed., revised): Alexandria, Va., American Geosciences Institute, 783 p. water boundary The boundary of water bodies contained within this database. This feature is included in the "MapUnitOverlayLines" feature class. The "MapUnitOverlayLines" features class delineates surficial material, water bodies, and sinkholes larger than 50m. The location is dictated by the base map originally used for publication. Users of this database should note that water boundaries vary through time and may not match current base maps and (or) lidar This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. IsConcealed Flag for contacts and faults covered by overlying map unit. GeMS Unrepresentable domain LocationConfidenceMeters Estimated half-width in meters of positional uncertainty envelope; position is relative to other features in database. GeMS Positive real number. Value of -9, -99, or -999 indicates value is unknown. ExistenceConfidence Confidence that feature exists. GeMS certain Identity of a feature can be determined using relevant observations and scientific judgment; therefore, one can be reasonably confident in the credibility of this interpretation Federal Geographic Data Committee [prepared for the Federal Geographic Data Committee by the U.S. Geological Survey], 2006, FGDC Digital Cartographic Standard for Geologic Map Symbolization: Reston, Va., Federal Geographic Data Committee Document Number FGDC-STD-013-2006, 290 p., 2 plates. IdentityConfidence Confidence that feature is correctly identified. GeMS certain Identity of a feature can be determined using relevant observations and scientific judgment; therefore, one can be reasonably confident in the credibility of this interpretation Federal Geographic Data Committee [prepared for the Federal Geographic Data Committee by the U.S. Geological Survey], 2006, FGDC Digital Cartographic Standard for Geologic Map Symbolization: Reston, Va., Federal Geographic Data Committee Document Number FGDC-STD-013-2006, 290 p., 2 plates. Label Plain-text equivalent of the desired annotation for a feature: for example "14 Ma", or "^c" which (when used with the FGDC GeoAge font) results in the geologic map-unit label TRc (with TR run together to make the Triassic symbol). GeMS Unrepresentable domain Symbol Reference to a point marker, line symbol, or area-fill symbol that is used on the map graphic to denote the feature: perhaps a star for a K-Ar age locality, or a heavy black line for a fault. GeMS Unrepresentable domain DataSourceID Source of data; foreign key to table DataSources. GeMS DASFRED100K003 This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. This report Notes Additional information specific to a particular feature or table entry. GeMS Unrepresentable domain. Free text. Values of <null> or #null indicate no entry. MapUnitOverlayLines_ID Primary key. GeMS Arbitrary string. Values should be unique within this database. Shape_Length Internal feature length, double ESRI Unrepresentable domain OverlayPolys Polygons that delineate underlying material, overlying material, or some aspect of earth materials other than the geologic map unit, e.g., dike swarm, alteration zone. On a map graphic, such polygons are commonly shown by a patterned overprint. In the original file geodatabase, this dataset is found within the GeologicMap feature dataset. GeMS OBJECTID Internal feature number ESRI Unrepresentable domain Shape Internal geometry object ESRI Unrepresentable domain Type Classifier that specifies what kind of geologic feature is represented by a database element: that a certain line within feature class ContactsAndFaults is a contact, or thrust fault, or water boundary; or that a point in GeochronPoints represents a K-Ar date. GeMS metamorphosed rock Thermally metamorphosed rocks (Lower Jurassic and Upper Triassic)—Variegated hornfels, quartzite, marble, meta-arkose, and metaconglomerate occurring as zoned contact aureoles adjacent to diabase intrusions. Includes dark-gray to olive-black, cordierite-spotted hornfels; bluish-gray epidote and chlorite hornfels; white to pinkish-gray tourmaline granofels or quartzite; greenish- to purplish-gray epidote and chlorite meta-arkose; and white, light-gray, and pink, crystalline marble. Contact aureoles a few meters thick adjoin narrow dikes, but can be more than 213 m thick and as much as 1.6 km wide adjacent to thick diabase sheets; rocks closer to the contacts are hard, brittle, fractured, and unweathered; sedimentary structures commonly preserved. This geologic map unit was placed into the "OverlayPolys" feature class to preserve the location and integrity of the underlying rock units in the "MapUnitPolys" feature class This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. sinkhole A closed depression in a karst or pseudokarst area, commonly with a circular or ellipsoidal pattern. Sinkhole locations with a value of less than or equal to 50 m2 in diameter are located within the "GenericPoints" feature class. Sinkholes greater than 50m2 in diameter are located in the "OverlayPolys" feature class AGI | DASFRED100K003 IdentityConfidence Confidence that feature is correctly identified. GeMS certain Identity of a feature can be determined using relevant observations and scientific judgment; therefore, one can be reasonably confident in the credibility of this interpretation Federal Geographic Data Committee [prepared for the Federal Geographic Data Committee by the U.S. Geological Survey], 2006, FGDC Digital Cartographic Standard for Geologic Map Symbolization: Reston, Va., Federal Geographic Data Committee Document Number FGDC-STD-013-2006, 290 p., 2 plates. Label Plain-text equivalent of the desired annotation for a feature: for example "14 Ma", or "^c" which (when used with the FGDC GeoAge font) results in the geologic map-unit label TRc (with TR run together to make the Triassic symbol). GeMS Unrepresentable domain Symbol Reference to a point marker, line symbol, or area-fill symbol that is used on the map graphic to denote the feature: perhaps a star for a K-Ar age locality, or a heavy black line for a fault. GeMS Unrepresentable domain DataSourceID Source of data; foreign key to table DataSources. GeMS DASFRED100K003 This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. This report Notes Additional information specific to a particular feature or table entry. GeMS Unrepresentable domain. Free text. Values of <null> or #null indicate no entry. OverlayPolys_ID Primary key. GeMS Arbitrary string. Values should be unique within this database. Shape_Length Internal feature length, double ESRI Unrepresentable domain Shape_Area Internal feature area, double ESRI Unrepresentable domain MapUnit Short plain-text identifier of the map unit. Foreign key to DescriptionOfMapUnits table. GeMS JTrtm Thermally metamorphosed rocks This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. MapUnitPolys Polygons that record distribution of map units (including water, snowfields, glaciers, and unmapped area) on the particular map horizon. In the original file geodatabase, this dataset is found within the GeologicMap feature dataset. GeMS OBJECTID Internal feature number ESRI Unrepresentable domain Shape Internal geometry object ESRI Unrepresentable domain MapUnit Short plain-text identifier of the map unit. Foreign key to DescriptionOfMapUnits table. GeMS Csql Lower member of the Sugarloaf Mountain Quartzite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ccwm Maryland Heights Member of the Weverton Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ccw Undivided rocks of the Weverton Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Jms Sander Basalt This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Obs Upper part of the Stonehenge Limestone This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cfl Lime Kiln Member of the Frederick Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Zrc Cobbler Mountain Alkali Feldspar Quartz Syenite of the Robertson River Igneous Suite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cclc Conglomerate of the Loudoun Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ylg Layered granitic gneiss This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Csqu Upper member of the Sugarloaf Mountain Quartzite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cfa Adamstown Member of the Frederick Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZsc Calcareous metasandstone of the Sams Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZl Loch Raven Schist This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ctd Dargan Member of the Tomstown Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cu Urbana Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cfrs Shale of the Rocky Springs Station Member of the Frederick Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Jmt Turkey Run Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Zfsm Metamudstone of the Swains Mountain Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ong Quartz gabbro of the Norbeck Intrusive Suite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZpq Quartzite of the Prettyboy Schist This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cs Sykesville Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZpb Metabasalt of the Prettyboy Schist This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Jmhs Sandstone and siltstone of the Hickory Grove Basalt This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Jmmc Conglomerate of the Midland Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ct Tomstown Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cum Marble of the Urbana Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ob Bear Island Granodiorite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Yc Charnockitic granite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ok Kensington Tonalite DASFRED100K055 | DASFRED100K047 CZu Mafic and ultramafic rocks This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Om Martinsburg Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZsf Felsic schist of the Sams Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cl Laurel Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZib Metabasalt of the Ijamsville Phyllite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Csqm Middle member of the Sugarloaf Mountain Quartzite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cf Undivided rocks of the Frederick Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Yqp Quartz-plagioclase gneiss This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Oq Quartz bodies This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZicp Chloritic phyllite of the Ijamsville Phyllite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Obrr Rockdale Run Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ypb Megacrystic metagranite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Zcm Metabasalt of the Catoctin Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Dg Guilford Granite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cca Antietam Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Zsp Phyllite of the Swift Run Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZmbq Quartzite of the Marburg Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ym Marshall Metagranite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cclp Phyllite of the Loudoun Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Zfsc Boulder conglomerate of the Swains Mountain Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZmt Metatuff of the Mather Gorge Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ccb Big Spring Station Member of the Conococheague Limestone This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Zsm Marble of the Swift Run Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Zrd Metarhyolite dike This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cuq Quartzite of the Urbana Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZip Phyllite of the Ijamsville Phyllite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Jdc High-titanium quartz-normative early cumulates This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ygt Garnetiferous metagranite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZmp Phyllonite of the Mather Gorge Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Zcp Tuffaceous phyllite of the Catoctin Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Jmh Hickory Grove Basalt This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZg Metagabbro and metapyroxenite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZn Northwest Branch Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Dp Pegmatite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ogg Quartz gabbro of the Georgetown Intrusive Suite Fleming, A.H., Drake, A.A., Jr., and McCartan, Lucy, 1994, Geologic map of the Washington West quadrangle, District of Columbia, Montgomery and Prince Georges Counties, Maryland, and Arlington and Fairfax Counties, Virginia: U.S. Geological Survey Geologic Quadrangle Map GQ– 1748, scale 1:24,000. CZmbb Metabasalt of the Marburg Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZsb Metabasalt of the Sams Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Trcbl Leesburg Member of the Bull Run Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Odm Biotite monzogranite and granodiorite of the Dalecarlia Intrusive Suite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Jdh High-titanium quartz-normative late cumulates This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ogh Biotite-hornblende tonalite of the Georgetown Intrusive Suite DASFRED100K033 | DASFRED100K047 Zcs Metasedimentary phyllite of the Catoctin Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cwac Chewsville Member of the Waynesboro Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Trcbb Balls Bluff Member of the Bull Run Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZsm Marble of the Sams Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. OCgu Upper Member of the Grove Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZp Prettyboy Schist This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Zss Metasandstone and schist of the Swift Run Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ccs Cash Smith Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Yp Garnet-graphite paragneiss This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cwact Cavetown Member of the Waynesboro Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Trcmp Poolesville Member of the Manassas Sandstone This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZmg Metagraywacke of the Mather Gorge Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Jcm Mount Zion Church Basalt This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZiq Quartzite of the Ijamsville Phyllite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Zmd Metadiabase dike This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Jmss Sandstone and siltstone of the Sander Basalt This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZlm Semipelitic schist and meta-arenite of the Loch Raven Schist This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Car Araby Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Jmm Midland Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZshp Hematitic phyllite of the Sams Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZsq Quartzite of the Sams Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Jmtc Conglomerate of the Turkey Run Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ctf Fort Duncan Member of the Tomstown Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZo Oella Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ccp Carbonaceous phyllite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cwar Red Run Member of the Waynesboro Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Zcr Metarhyolite of the Catoctin Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZw Wakefield Marble This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Zcma Marble of the Catoctin Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZil Metalimestone of the Ijamsville Phyllite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Yg White leucocratic metagranite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cchs Metasandstone of the Harpers Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZmbg Metagraywacke of the Marburg Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ypg Porphyroblastic metagranite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ce Elbrook Limestone This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ccwb Buzzard Knob Member of the Weverton Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ont Biotite-hornblende tonalite of the Norbeck Intrusive Suite Hopson, C.A., 1964, The crystalline rocks of Howard and Montgomery Counties, Md., in The geology of Howard and Montgomery Counties: Baltimore, Maryland Geological Survey, p. 27–215. Ogp Metapyroxenite of the Georgetown Intrusive Suite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZsl Metalimestone of the Sams Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Zfcr Carter Run Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Obps Pinesburg Station Dolomite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZms Quartz-rich schist of the Mather Gorge Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Onu Ultramafic rocks of the Norbeck Intrusive Suite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Yhm Hornblende monzonite gneiss This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ya Amphibolite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ccwo Owens Creek Member of the Weverton Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. JTrcc Catharpin Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZsmp Muscovitic phyllite of the Sams Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Yq Quartzite and quartz-sericite tectonite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZim Marble of the Ijamsville Phyllite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cch Harpers Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ctb Benevola Member of the Tomstown Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Trcmt Tuscarora Creek Member of the Manassas Sandstone This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZsd Soldiers Delight Ultramafite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Kps Potomac Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZsqp Quartzite interbedded with phyllite of the Sams Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. OCgl Lower Member of the Grove Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZic Phyllitic conglomerate of the Ijamsville Phyllite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZicm Conglomeratic metagraywacke of the Ijamsville Phyllite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZss Metasiltstone of the Sams Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Oc Chambersburg Limestone This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. JTrccg Goose Creek Member of the Catharpin Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ymc Coarse-grained metagranite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Odt Muscovitic trondhjemite of the Dalecarlia Intrusive Suite Fleming, A.H., Drake, A.A., Jr., and McCartan, Lucy, 1994, Geologic map of the Washington West quadrangle, District of Columbia, Montgomery and Prince Georges Counties, Maryland, and Arlington and Fairfax Counties, Virginia: U.S. Geological Survey Geologic Quadrangle Map GQ– 1748, scale 1:24,000. CZstp Tuffaceous phyllite of the Sams Creek Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ccwmq Quartzite of the Maryland Heights Member of the Weverton Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ontr Trondhjemite of the Norbeck Intrusive Suite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Odl Leucocratic muscovite-biotite monzogranite of the Dalecarlia Intrusive Suite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ybg Biotite granite gneiss This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Osnr New Market and Row Park Limestones undivided, of the St. Paul Group This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ctbh Bolivar Heights Member of the Tomstown Formation Brezinski, D.K., 1996, Stratigraphy of the Elbrook Formation (Middle to Upper Cambrian) in Maryland and adjacent States, in Brezinski, D.K., and J.P. Reger, eds., Studies in Maryland geology: Maryland Geological Survey Special Publication 3, p. 165–186. CZmm Migmatite of the Mather Gorge Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. CZmbs Metasiltstone of the Marburg Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. OCc Conococheague Limestone This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Clu Upper part of the Laurel Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Trcmr Reston Member of the Manassas Sandstone This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Cfr Rocky Springs Station Member of the Frederick Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Jdg Granophyre This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Yml Pink leucocratic metagranite This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Jd Crystalline diabase This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Ct* Tomstown Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Trcbg Groveton member of the Bull Run Formation This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. Obss Stoufferstown Member of the Stonehenge Limestone This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. IdentityConfidence Confidence that feature is correctly identified. GeMS certain Identity of a feature can be determined using relevant observations and scientific judgment; therefore, one can be reasonably confident in the credibility of this interpretation Federal Geographic Data Committee [prepared for the Federal Geographic Data Committee by the U.S. Geological Survey], 2006, FGDC Digital Cartographic Standard for Geologic Map Symbolization: Reston, Va., Federal Geographic Data Committee Document Number FGDC-STD-013-2006, 290 p., 2 plates. questionable Identity of a feature cannot be determined using relevant observations and scientific judgment; therefore, one cannot be reasonably confident in the credibility of this interpretation. For example, IdentityConfidence = questionable is appropriate when a geologist reasons "I can see some kind of planar feature that separates map units in this outcrop, but I cannot be certain if it is a contact or a fault" Federal Geographic Data Committee [prepared for the Federal Geographic Data Committee by the U.S. Geological Survey], 2006, FGDC Digital Cartographic Standard for Geologic Map Symbolization: Reston, Va., Federal Geographic Data Committee Document Number FGDC-STD-013-2006, 290 p., 2 plates. Label Plain-text equivalent of the desired annotation for a feature: for example "14 Ma", or "^c" which (when used with the FGDC GeoAge font) results in the geologic map-unit label TRc (with TR run together to make the Triassic symbol). GeMS Unrepresentable domain Symbol Reference to a point marker, line symbol, or area-fill symbol that is used on the map graphic to denote the feature: perhaps a star for a K-Ar age locality, or a heavy black line for a fault. GeMS Unrepresentable domain DataSourceID Source of data; foreign key to table DataSources. GeMS DASFRED100K003 This Report, Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. text. This report Notes Additional information specific to a particular feature or table entry. GeMS Unrepresentable domain. Free text. Values of <null> or #null indicate no entry. MapUnitPolys_ID Primary key. GeMS Arbitrary string. Values should be unique within this database. Pattern These are the FGDC patterns from the FGDC geologic map symbolization document. They match the patterns to the closest approximate pattern used on the original geologic map. The patterns used in the original publication predate the FGDC geologic map symbolization document and will not match perfectly DASFRED100K003 Unrepresentable domain Shape_Length Internal feature length, double ESRI Unrepresentable domain Shape_Area Internal feature area, double ESRI Unrepresentable domain Detailed descriptions of entities, attributes, and attribute values are given in metadata for constituent elements of the database. See also "GeMS (Geologic Map Schema)--a standard format for the digital publication of geologic maps", available at http://ngmdb.usgs.gov/Info/standards/GeMS/. Southworth, Scott, Brezinski, D.K., Drake, A.A., Jr., Burton, W.C., Orndorff, R.C., Froelich, A.J., Reddy, J.E., Denenny, Danielle, and Daniels, D.L., 2007, Geologic map of the Frederick 30 x 60 quadrangle, Maryland, Virginia, and West Virginia: U.S. Geological Survey Scientific Investigations Map 2889, scale 1:100,000, 42-p. pamphlet, https://pubs.usgs.gov/sim/2889/ U.S. Geological Survey GS ScienceBase mailing

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Denver CO 80225 US 1-888-275-8747 sciencebase@usgs.gov Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Digital Data https://doi.org/10.5066/P13REKRW None 20250430 U.S. Geological Survey, Northeast Region Ernest A Crider Geologist mailing

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