Hall, S.M [0000-0002-0931-8694] Lowers, H.A. [0000-0001-5360-9264] 20250414 images https://doi.org/10.5066/P13S3RGB These data are microanalyses of 22 polished thin sections that were examined using a scanning electron microscope (SEM) equipped with an energy dispersive spectrometer (EDS) to identify minerals and observe their relationships at high magnification. Samples are from uranium mineralized core drilled at the Coles Hill uranium deposit, Pittsylvania County, Virginia, and one sample of the host rock collected from a surface outcrop about 5 miles from the deposit. The Coles Hill deposit is hosted in the Taconian (approx. 480-450 Ma) Martinsville igneous complex, and a genetic model for the deposit was published in 2022 (Hall et al., 2022). The thin sections are identified by the drill hole id (Table 1) followed by the depth at which the sample was collected. For instance, thin section 41-125-424 was collected from Coles Hill drill hole number 41-125, at 424 feet below the collar of the drill hole (as measured along the trace of the hole). The spectra for EDS measurements are provided in separate documents in .docx (word) files, with one document for each area within the thin section (e.g., 41-125-424_area1_EDS) that was examined. Element spectra were collected in multiple spots within each area, with element ID provided by the EDS vendor algorithm. The separation between areas is marked by successively labeled files (e.g. area 1, area 2, and so on). For most sample areas in the thin sections, higher-resolution images are also provided as part of this data release. The images are titled with the drill hole/thin section number (e.g., 41-125_424) followed by the sampled area (e.g., 41-125-424_area1) then the image type (e.g., SEI, BSE, or MAP). The naming convention for image types is "SEI” for images taken using a secondary electron detector and “BSE” for images taken using the backscattered electron detector. Where captured, an image “MAP” is also provided showing the location of the area that was analyzed on a composite backscattered electron detector image of the thin section. In limited circumstances more detailed higher-resolution images were captured for areas of particular interest and these are listed as “detail” images (e.g. 41-125-424_area2detail_VCD). In other limited circumstances, zoomed-out images and element spectra were captured to record the mineralogical context of the area details; and these are designated “overview” images. The thin sections and rock samples are stored in an area known as the hot rocks room, Building 810, Denver Federal Center, Lakewood, Colorado, USA. The data are the results of a multi-year study of uranium mineralized orthogneiss at the Coles Hill deposit, Virginia, USA. The samples were collected and prepared for study under high magnification to aid in mineral identification and mineral paragenesis in support of the development of a genetic model for the Coles Hill deposit. This work is the basis for ongoing national assessments of undiscovered uranium resources. This data release is intended to provide all the microanalytic data that was acquired as part of this study to other researchers for use in future scientific studies. Data are organized into two folders, EDAX and SEM. The EDAX folder contains files generated by the EDS vendor showing a reference electron image, and the different sites within each image that were analyzed. The SEM folder contains higher resolution electron images of the samples within the EDAX folder. 1978 1982 ground condition Complete None planned -79.30450 -79.25360 36.93960 36.87000 ISO 19115 Topic Category geoscientificInformation USGS Energy Resources uranium metasomatite Coles Hill Virginia SEM microanalysis EDS EDAX USGS Metadata Identifier USGS:67d3078ad34e1acf3979cde3 Common Geographic Areas Virginia None. Please see 'Distribution Info' for details. None. Users are advised to read the dataset's metadata thoroughly to understand appropriate use and data limitations. Susan M Hall USGS - ROCKY MOUNTAIN REGION mailing and physical

DFC, MS 939

Denver CO 80225 303-236-1656 susanhall@usgs.gov S. M. Hall J. S. Beard C. J. Potter R. J. Bodnar L. A. Neymark J. B. Paces C. A. Johnson G. N. Breit R. A. Zielinski G. J. Aylor 20220301 publication Economic Geology vol. 117, issue 2 n/a Society of Economic Geologists ppg. 273-304 https://doi.org/10.5382/econgeo.4874 A spot check on Co metal was performed at the beginning of each batch of samples. The data are for informational purposes only and were used as an aid to identify minerals based on peak height ratios of individual elements. The visual images and qualitative chemical results fall within expected ranges for the mineralogy of this deposit. Data has neither been duplicated nor omitted. These data contain the morphological and chemical analysis of minerals and phases. The chemical data provided by scanning electron microscope energy dispersive data is informational only. The core sampled for this study was drilled by the Marline Uranium Corporation between 1978 and 1982 and was donated to the Virginia Museum of Natural History in 1990. In 2014, the U. S. Geological Survey collected about 2- to 5-inch-long samples of 3- and 6-inch diameter drill core samples from this collection. For the microanalysis of this rock, samples were selected from 10 drill cores at the locations listed in Table 1. The drill hole number is recorded in the first number clusters of the sample numbers (i.e. Drill hole 41-125 in sample 41-125-424), and the depth that was sampled in the drilled hole is recorded in the third number cluster (i.e. 424 feet from the collar in sample 41-125-424). Note that not all the holes were drilled vertically with drilled azimuth and dips (when available) shown on Table 1. One sample of unaltered Leatherwood Granite, located about 5 miles from the Coles Hill deposit area (Table 1), was also included in the sample set. Polished thin sections were created from these samples using commercial laboratories. Before analysis by SEM-EDS, the thin sections were coated with approximately 20 nm of carbon. The samples were examined using a scanning electron microscope (SEM), located at the USGS Denver Microbeam Lab in Lakewood Colorado. This SEM is equipped with an energy dispersive spectrometer (EDS) to identify elements and observe the relationships of minerals at high magnification. Images from areas on the thin sections were acquired using an Everhart-Thornley secondary electron detector and backscattered electron voltage contrast detector on a FEI Quanta 450-FEG scanning electron microscope. A range of operating conditions and magnifications were used to optimize imaging and chemical analyses. However, most analyses were collected at 15 or 20 kilovolts and approximately 0.5 to 1 nanoamperes of current. Dwell times ranged from 3 to 10 microseconds per pixel with an image resolution of 2048 x 1886. Each image was saved as an 8-bit .tif file format. At the bottom of each image is a data bar that displays the accelerating voltage (HV), magnification (mag), horizontal field width (HFW), working distance (WD), detector (det), and scale bar for image acquisition. An energy dispersive spectrum was collected on selected areas as viewed in the electron images. EDS collection was done on two systems. One EDS set, labeled “EDAX Team” on each EDS file, was collected with an EDAX Team silicon drift detector and software at 15 kilovolts and count times ranging from 3 to 30 seconds live count time with the pulse processor amp time set to a value of 0.5 us. The second EDS acquisition, labeled “Oxford Instruments” on each EDS file, was performed with an Oxford Instruments XMax 50 silicon drift detector. Count times ranged from 5 to 20 seconds with a pulse process setting of 2 or 3. Automatic peak identification was performed by the software and not evaluated for accuracy. A report (PDF or .doc files) was generated for each area that contains the image and location of the EDS spectrum within the image. EDS data is not quantified and considered informational only. 2018 Coles Hill SEM Data Release Table 1.csv Comma Separated Value (CSV) file containing data. Producer Defined Hole_ID the drill hole number Producer Defined drill hole number Total Depth (feet) the total depth of the drill hole Producer Defined na not available Producer defined 550 1105 feet Drill Hole Diameter (inches) the diameter in inches of the drill hole sample Producer Defined na not available Producer defined 3 6 inches Dip of Hole (degrees) dip in degrees at which the hole was drilled Producer Defined na not available Producer defined 50 90 degrees Azimuth of Hole (degrees) direction in degrees from north at which the hole was drilled Producer Defined na not available Producer defined 28 304 degrees Collar Elevation (feet) Elevation in feet where drilling was initiated. Producer Defined 606.6 697.44 feet long_WGS84 decimal degrees latitude Producer Defined -79.30446447 -79.25367 datum of WGS1984 lat_WGS84 decimal degrees longitude Producer Defined 36.87002319 36.93962 datum of WGS1984 Column descriptions for EDS files and .csv Column descriptions for the tables in the EDS files: Weight %: elemental weight percent Atomic %: atomic percent Net INt.: net intensity of peak Error%: percent error Kratio: ratio of counts in unknown to standard Z: atomic number correction factor R: backscattered correction factor A: absorption correction factor F: fluorescence correction factor U.S. Geological Survey - ScienceBase mailing address

Denver Federal Center

Building 810

Mail Stop 302

Denver CO 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 for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. Digital Data https://doi.org/10.5066/P13S3RGB None 20250414 Christa D Chavez USGS - ROCKY MOUNTAIN REGION Information Technology Specialist mailing and physical

Denver Federal Center, Bldg 25

Lakewood CO 80225 303-236-1644 datamgt@usgs.gov FGDC Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998