Version 2025-12-04: (_v2 files) Change Log
As of the December 2025 reupload (_v2) of this data, the below errors are corrected in the .csv and the shapefile.

The lab data folder contains a .csv and a point shapefile that includes locations of samples analyzed for trace and major elements joined to analytical lab data.  Descriptions of analytical data fields are included in csv file.  Please note, shapefile truncates field names for analytical data. 

Sample analytical method information can be obtained from the USGS publication: "Geochemical data generated by projects funded by the USGS Earth Mapping Resources Initiative (ver. 11.0, January 2025)"; doi:10.5066/P9WHRLXH.
Full citation: U.S. Geological Survey, 2021, Geochemical data generated by projects funded by the USGS Earth Mapping Resources Initiative (ver. 11.0, January 2025): U.S. Geological Survey data release, https://www.sciencebase.gov/catalog/item/601963c6d34edf5c66f0d0e5.

Depth_FT is measured in feet from top of clay bed/base of overlying coal.

Both the original (_v1 files) point shapefile and .csv on the Maryland Geological Survey website inadvertently omitted several columns of data results. The omitted data resulted in translation of data values to be shown under inaccurate data headers in the .csv and shapefile and may have misrepresented sample results. The omitted columns of data are listed below from the .csv file.
WDXRF_CaO_percent
ICP60_Zr_ppm
ICP60_W_ppm
ICP60_Sr_ppm
ICP60_Se_ppm
ICP60_Pr_ppm
ICP60_Lu_ppm
ICP60_Hf_ppm
ICP60_Cs_ppm
ICP60_Be_ppm

The original (_v1) point shapefile contained mislabeled data results for several analytical columns. The mislabeled columns in the shapefile data are listed below:
The column labeled ICP60_Hf_ppm contained data for ICP60_Ho_ppm.
The column labeled ICP60_W_ppm contained data for ICP60_Y_ppm.
The column labeled ICP60_Zr_ppm contained data for WDXRF_Al2O3_percent.

Version 2022-10-11:
The lab data folder contains a .csv and a point shapefile that includes locations of samples analyzed for trace and major elements joined to analytical lab data.  Descriptions of analytical data fields are included in csv file.  Please note, shapefile truncates field names for analytical data.