Anne E. McCafferty 20160601 CSV Denver, CO U.S. Geological Survey http://dx.doi.org/10.5066/F78P5XM4 High resolution magnetic and gravity gradient data were collected using the HeliFalcon airborne gravity gradiometry system together with a stinger-mounted magnetometer. The survey took place out of the Sullivan, Missouri airport during March of 2014. The survey covers a 35 x 37 square-kilometer area centered on the Pea Ridge iron oxide-apatite rare-earth element deposit, which is located about halfway between the towns of Sullivan and Potosi, Missouri. Data were collected along north-south flight lines spaced 400 m apart with east-west tie lines flown every 4000 m. A nominal flight height above terrain of 80 m was maintained except where safety dictated a higher elevation. A total of 3538 line km of data were collected. Three files are available in this publication and include flight line data for the magnetic survey, flight line data for the gravity gradiometry survey and a report describing the survey parameters, field operations, quality control and data reduction procedures. The helicopter borne high-resolution magnetic and gravity gradiometry survey was flown as one component of a U.S. Geological Survey (USGS) mineral resource project to investigate the iron oxide copper-cobalt-gold-REE deposits in southeast Missouri. The survey was designed to specifically target areas known to host iron oxide deposits including the Pea Ridge iron mine, and two other known but undeveloped iron oxide deposits at Kratz Spring and Bourbon. All the targeted iron oxide deposits are hosted in Mesoproterozoic igneous rocks, which are concealed beneath 300 or more meters of Cambrian sedimentary sandstones and carbonate units. This metadata describes three files: USA_Southeast_Missouri_Region_AirborneMagnetics.csv - flight line data for the magnetic survey USA_Southeast_Missouri_Region_GravityGradiometry.csv - flight line data for the gravity gradiometry survey HeliFalconMissouriGeophysical_Survey_Report.pdf - report from contractor describing the survey parameters, field operations, quality control and data reduction procedures 20140303 20140328 ground condition Complete Not planned -91.2904 -90.8788 38.3211 38.0 USGS Thesaurus geophysics magnetic surveying aeromagnetic surveying magnetic field (earth) gravimetric methods gravitational field (earth) gravimeter measurement gravity field geospatial datasets ISO 19115 Topic Category geoscientificInformation none aeromag aeromagnetic airborne magnetic survey airborne gravity gradiometry USGS Metadata Identifier USGS:5730a3a0e4b0dae0d5db1eab Geographic Names Information System Missouri Pea Ridge Mine Bourbon Sullivan Sullivan Regional Airport None. Please see 'Distribution Info' for details. There is no guarantee concerning the accuracy of the data. Any user who modifies the data is obligated to describe the types of modifications they perform. Data have been checked to ensure the accuracy. If any errors are detected, please notify the originating office. The U.S. Geological Survey strongly recommends that careful attention be paid to the metadata file associated with these data. Acknowledgment of the U.S. Geological Survey would be appreciated in products derived from these data. User specifically agrees not to misrepresent the data, nor to imply that changes made were approved or endorsed by the U.S. Geological Survey. Please refer to http://www.usgs.gov/privacy.html for the USGS disclaimer. Anne E. McCafferty U.S. Geological Survey, Crustal Geophysics and Geochemistry Science Center mailing and physical

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Denver Colorado 80225 United States 303 236-1397 anne@usgs.gov USGS Mineral Resource Program provided the funding. These data were acquired by CGG, Ontario for the U.S. Geological Survey. No formal attribute accuracy tests were conducted Daily quality control was performed by the USGS and the contractor during daily flights of raw magnetic and gravity gradiometry data. Further quality control measures occurred post flight by the office based contractor data processor and USGS scientist-in-charge before approval and acceptance of final data. Data set 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. Recorded airborne raw GPS data were used in Waypoint's GrafNav GPS processing sofware to calculate GPS positions obtained from the moving (airborne) and stationary (ground) receivers. No formal positional accuracy tests were conducted. Recorded airborne raw GPS data were used for in Waypoint's GrafNav GPS processing sofware to calculate GPS positions obtained from the moving (airborne) and stationary (ground) receivers. No formal positional accuracy tests were conducted. Daily quality control, initial processing and archiving of the data were done on-site at the base of operations in Sullivan, MO. 20140328 The final data processing, map generation and report writing were undertaken at the offices of CGG, Ontario, Canada for the magnetic data and CGG, Perth for the airborne gravity gradiometry data. Processing steps for the gravity gradiometry and magnetic data involve several dozen steps, which are outlined in Figures 8 and 15, respectively, in the HeliFalconMissouriGeophysical_Survey_Report.pdf that is part of this data release. 20140330 Final data and report were received from CGG. 20140440 Final data were exported to CSV-format to meet open data requirements. 20160501 Geographic Names Index System (GNIS) placenames Point 1.0E-5 1.0E-5 Decimal degrees WGS84 WGS84 6378137.0 298.257 USA_Southeast_Missouri_Region_AirborneMagnetics.csv ASCII Text CSV Table of Airborne Magnetic Survey Results CGG, Ontario under contract to the U.S. Geological Survey Line Line number Contractor report Line number ALTRAD radar altimeter reading in meters Contractor report radar altimeter reading in meters JulianDate Year and Julian date (ordinal dates IOS_8601) Contractor report Year and Julian date (ordinal dates IOS_8601) DIURNAL_COR Diurnal correction-base removed Contractor report Diurnal correction-base removed in nT DIURNAL measured ground magnetic intensity in nT Contractor report measured ground magnetic intensity in nT FID Fiducial Contractor report A fiducial value is a shared sequential timing reference for geophysical measurements collected during the survey flight. Flight Flight number Contractor report contractor's definition of flight number FX fluxgate magnetometer, component 1x direction Contractor report fluxgate magnetometer, component 1x direction in nT FY Fluxgate magnetometer, component 2y direction Contractor report Fluxgate magnetometer, component 2y direction in nT FZ Fluxgate magnetometer, component 3z direction Contractor report Fluxgate magnetometer, component 3z direction in nT IGRF International Geomagnetic Reference Field Contractor report International Geomagnetic Reference Field in nT lat_wgs84 Latitude in WGS84 Contractor report Latitude in WGS84 in decimal degrees lon_wgs84 Longitude in WGS84 Contractor report Longitude in WGS84 in decimal degrees MAG_RAW Total magnetic field (compensated) Contractor report Total magnetic field (compensated) in nT MAG_LAG Total magnetic field-corrected for lag Contractor report Total magnetic field-corrected for lag in nT MAG_DIU Total magnetic field-diurnal variation removed Contractor report Total magnetic field-diurnal variation removed in nT MAG_Tie Total magnetic field-tie line leveled Contractor report Total magnetic field-tie line leveled in nT MAG_LEV Total magnetic field-leveled Contractor report Total magnetic field-leveled in nT TMF Total Magnetic field (IGRF removed and mean value added back) U.S.Geological Survey Total Magnetic field (IGRF removed and mean value added back in nT) X_wgs84 Easting (X) in WGS84 UTM Zone 15N Contractor report Easting (X) in WGS84 UTM Zone 15N in meters Y_wgs84 Northing (Y) in WGS84 UTM Zone 15N Contractor report Northing (Y) in WGS84 UTM Zone 15N in meters UTC_TIME Universal time (seconds since midnight) Contractor report Universal time (seconds since midnight) bearing Flight line direction Contractor report Flight line direction in degrees DATE Date of survey flight Contractor report date of survey flight in MM/DD/YYYY GPSZ Global Positioning System elliptic height Contractor report Global Positioning System elliptic height in meters USA_Southeast_Missouri_Region_GravityGradiometry.csv ASCII Text CSV Table of Airborne Gravity Gradiometry Survey Results CGG, Ontario under contract to the U.S. Geological Survey Line Line number Contractor report Line number Flight flight number Contractor report Flight number Julian Date Year and Julian date (ordinal dates ISO_8601) Contractor report Julian Date in YYYYDDD format x_wgs84 Easting (X) in WGS84 UTM Zone 15N Contractor report Easting (X) in WGS84 UTM Zone 15N in meters y_wgs84 Northing (Y) in WGS84 UTM Zone 15N Contractor report Northing (Y) in WGS84 UTM Zone 15N in meters Lon_wgs84 Longitude in WGS84 Contractor report Longitude in WGS84 in decimal degrees Lat_wgs84 Latitude in WGS84 in decimal degrees Contractor report latitude in WGS84 in decimal degrees Lat_wgs84 Latitude in WGS84 in decimal degrees Contractor report latitude in WGS84 in decimal degrees gpsz GPS Elevation (Referenced to EGM96 geoid) GPS Elevation (Referenced to EGM96 geoid) in meters Fid Universal Time (Seconds since January 6 1980) Universal Time (Seconds since January 6 1980) in seconds UTC_Time Universal Time (Seconds since midnight) Universal Time (Seconds since midnight) in seconds Bearing Flight line direction Flight line direction in degrees HEIGHT Flying height (aircraft's height above terrain as derived from laser scanner and ALTITUDE data) Flying height (aircraft's height above terrain as derived from laser scanner and ALTITUDE data) in meters DTM Terrain height above WGS84 ellipsoid with geoid (EGM96) correction applied (sampled from DTM grid) Terrain height above WGS84 ellipsoid with geoid (EGM96) correction applied (sampled from DTM grid) in meters Turbulence Estimated vertical platform turbulence (vertical acceleration where g = 9.80665 m/sec/sec) Estimated vertical platform turbulence (vertical acceleration where g = 9.80665 m/sec/sec) in milli g T_DD Terrain effect calculated for DD using a density of 1 g/cc Terrain effect calculated for DD using a density of 1 g/cc in eotvos T_NE Terrain effect calculated for NE using a density of 1 g/cc Terrain effect calculated for NE using a density of 1 g/cc in eotvos T_UV Terrain effect calculated for UV using a density of 1 g/cc Terrain effect calculated for UV using a density of 1 g/cc in eotvos Err_NE NE gradient uncorrelated noise estimate after levelling NE gradient uncorrelated noise estimate after levelling in eotvos Err_UV UV gradient uncorrelated noise estimate after levelling UV gradient uncorrelated noise estimate after levelling in eotvos A_NE_2p67 Self gradient & terrain corrected NE gradient using terrain correction density 2.67 g/cc Self gradient & terrain corrected NE gradient using terrain correction density 2.67 g/cc in eotvos A_UV_2p67 Self gradient & terrain corrected UV gradient using terrain correction density 2.67 g/cc Self gradient & terrain corrected UV gradient using terrain correction density 2.67 g/cc in eotvos B_NE_2p67 Self gradient & terrain corrected NE gradient using terrain correction density 2.67 g/cc Self gradient & terrain corrected NE gradient using terrain correction density 2.67 g/cc in eotvos B_UV_2p67 Self gradient & terrain corrected UV gradient using terrain correction density 2.67 g/cc Self gradient & terrain corrected UV gradient using terrain correction density 2.67 g/cc in eotvos A_NE_0 Self gradient corrected NE gradient only with no terrain correction applied Self gradient corrected NE gradient only with no terrain correction applied in eotvos A_UV_0 Self gradient corrected UV gradient only with no terrain correction applied Self gradient corrected UV gradient only with no terrain correction applied in eotvos B_NE_0 Self gradient corrected NE gradient only with no terrain correction applied Self gradient corrected NE gradient only with no terrain correction applied in eotvos B_UV_0 Self gradient corrected UV gradient only with no terrain correction applied Self gradient corrected UV gradient only with no terrain correction applied in eotvos gD_FOURIER_2p67 Fourier derived vertical Gravity using terrain correction density 2.67 g/cc and 400 m cut-off wavelength Fourier derived vertical Gravity using terrain correction density 2.67 g/cc and 400 m cut-off wavelength in mGal GDD_FOURIER_2p67 Fourier derived vertical gravity gradient using terrain correction density 2.67 g/cc and 400 m cut-off wavelen Fourier derived vertical gravity gradient using terrain correction density 2.67 g/cc and 400 m cut-off wavelen in eotvos GEE_FOURIER_2p67 Fourier derived Gee gravity gradient using terrain correction density 2.67 g/cc and 400 m cut-off wavelength Fourier derived Gee gravity gradient using terrain correction density 2.67 g/cc and 400 m cut-off wavelength in eotvos GNN_FOURIER_2p67 Fourier derived Gnn gravity gradient using terrain correction density 2.67 g/cc and 400 m cut-off wavelength Fourier derived Gnn gravity gradient using terrain correction density 2.67 g/cc and 400 m cut-off wavelength in eotvos GED_FOURIER_2p67 Fourier derived Ged horizontal EW gravity gradient using terrain correction density 2.67 g/cc and 400 m cut-off wavelength Fourier derived Ged horizontal EW gravity gradient using terrain correction density 2.67 g/cc and 400 m cut-off wavelength in eotvos GND_FOURIER_2p67 Fourier derived Gnd horizontal NS gravity gradient using terrain correction density 2.67 g/cc and 400 m cut-off wavelength Fourier derived Gnd horizontal NS gravity gradient using terrain correction density 2.67 g/cc and 400 m cut-off wavelength in eotvos GNE_FOURIER_2p67 Fourier derived Gne gravity curvature gradient using terrain correction density 2.67 g/cc and 400 m cut-off wavelength Fourier derived Gne gravity curvature gradient using terrain correction density 2.67 g/cc and 400 m cut-off wavelength in eotvos GUV_FOURIER_2p67 Fourier derived vertical Gravity with no terrain correction applied and 400 m cut-off wavelength Fourier derived vertical Gravity with no terrain correction applied and 400 m cut-off wavelength in mGal gD_FOURIER_0 Fourier derived vertical gravity gradient with no terrain correction applied and 400 m cut-off wavelength Fourier derived vertical gravity gradient with no terrain correction applied and 400 m cut-off wavelength in eotvos GDD_FOURIER_0 Fourier derived Gee gravity gradient with no terrain correction applied and 400 m cut-off wavelength Fourier derived Gee gravity gradient with no terrain correction applied and 400 m cut-off wavelength in eotvos GEE_FOURIER_0 Fourier derived Gnn gravity gradient with no terrain correction applied and 400 m cut-off wavelength Fourier derived Gnn gravity gradient with no terrain correction applied and 400 m cut-off wavelength in eotvos GNN_FOURIER_0 Fourier derived Ged horizontal EW gravity gradient with no terrain correction applied and 400 m cut-off wavelength Fourier derived Ged horizontal EW gravity gradient with no terrain correction applied and 400 m cut-off wavelength in eotvos GED_FOURIER_0 Fourier derived Ged horizontal EW gravity gradient with no terrain correction applied and 400 m cut-off wavelength Fourier derived Ged horizontal EW gravity gradient with no terrain correction applied and 400 m cut-off wavelength in eotvos GND_FOURIER_0 Fourier derived Gnd horizontal NS gravity gradient with no terrain correction applied and 400 m cut-off wavelength Fourier derived Gnd horizontal NS gravity gradient with no terrain correction applied and 400 m cut-off wavelength in eotvos GNE_FOURIER_0 Fourier derived Gne gravity curvature gradient with no terrain correction applied and 400 m cut-off wavelength Fourier derived Gne gravity curvature gradient with no terrain correction applied and 400 m cut-off wavelength in eotvos GUV_FOURIER_0 Fourier derived Guv gravity curvature gradient with no terrain correction applied and 400 m cut-off wavelength Fourier derived Guv gravity curvature gradient with no terrain correction applied and 400 m cut-off wavelength in eotvos DRAPESURFACE_FOURIER Drape surface for Fourier reconstruction (smoothed flight surface) Drape surface for Fourier reconstruction (smoothed flight surface) in meters gD_EQUIV_2p67 Equivalent source derived vertical Gravity with terrain correction density 2.67 g/cc and source depth 400 m Equivalent source derived vertical Gravity with terrain correction density 2.67 g/cc and source depth 400 m in mGal GDD_EQUIV_2p67 Equivalent source derived vertical gravity gradient with terrain correction density 2.67 g/cc and source depth 400 m Equivalent source derived vertical gravity gradient with terrain correction density 2.67 g/cc and source depth 400 m in eotvos GNE_EQUIV_2p67 Equivalent source derived Gne gravity curvature gradient with terrain correction density 2.67 g/cc and source depth 400 m Equivalent source derived Gne gravity curvature gradient with terrain correction density 2.67 g/cc and source depth 400 m in eotvos GUV_EQUIV_2p67 Equivalent source derived Guv gravity curvature gradient with terrain correction density 2.67 g/cc and source depth 400 m Equivalent source derived Guv gravity curvature gradient with terrain correction density 2.67 g/cc and source depth 400 m in eotvos gD_EQUIV_0 Equivalent source derived vertical Gravity (no terrain correction applied) source depth 400 m Equivalent source derived vertical Gravity (no terrain correction applied) source depth 400 m in mGal GDD_EQUIV_0 Equivalent source derived vertical gravity gradient (no terrain correction applied) source depth 400 m Equivalent source derived vertical gravity gradient (no terrain correction applied) source depth 400 m in eotvos GNE_EQUIV_0 Equivalent source derived Gne gravity curvature gradient (no terrain correction applied) source depth 400 m Equivalent source derived Gne gravity curvature gradient (no terrain correction applied) source depth 400 m in eotvos GUV_EQUIV_0 Equivalent source derived Guv gravity curvature gradient (no terrain correction applied) source depth 400 m Equivalent source derived Guv gravity curvature gradient (no terrain correction applied) source depth 400 m in eotvos DRAPESURFACE_EQUIV Drape surface for equivalent source reconstruction (smoothed flight surface) Drape surface for equivalent source reconstruction (smoothed flight surface) in meters ObservationSurface ?? ?? in date Date of survey flight Contractor report Date of the survey flight YYYY/MM/DD HeliFalconMissouriGeophysical_Survey_Report.pdf This report describes a high-sensitivity aeromagnetic and HeliFalcon(TM) airborne gravity gradiometry survey over the Sullivan, Missouri area under contract to the U.S. Geological Survey. CGG, Ontario, Canada: Airborne geophysical contractor for the U.S. Geological Survey. report N/A Contractor report This report describes the survey parameters, field operations, quality control results, and data reduction procedures used to produce the aeromagnetic and gravity gradiometry data. U.S. Geological Survey – ScienceBase UU.S. Geological Survey – ScienceBase mailing and physical

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Denver Colorado 80225 United States 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. 20200929 Anne E. McCafferty U.S. Geological Survey, Crustal Geophysics and Geochemistry Science Center Research Geophysicist mailing and physical

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Denver Colorado 80225 United States 303 236-1397 anne@usgs.gov Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998