The Paleocene Fort Union Formation hosts a compositionally diverse array of Eocene plugs, dikes, and sills arrayed around the Eocene Big Timber stock in the Crazy Mountains of south-central Montana. The geochemistry and petrography of the sills have no

The spatial databases represent the original content of 43 published geologic maps, provide normalized map unit descriptions, and provide additional information and interpretation not in the original reports.

Geologic map unit and lithologic descriptions used in Open File Report 2005-1235, with extensive bibliographic references to geologic literature that could not be included in the spatial database.

Polygons that describe areas of rock outcrop in the area of the Stillwater Complex, Montana from published reports and field mapping sheets. Includes both legacy data and outcrops from recent field mapping. This dataset contains overlapping polygons, as some areas had mapping from different sources that overlapped the same locations. Data are provided in shapefile format.

Data from a helicopter-borne electromagnetic and magnetic survey flown over this area area in 2000. Nominal elevation of the sensor was 60 meters. Survey coverage comprises 1,914 line kilometers. Data are provided in CSV format.

Photographs and micrographs of rock taken from cores in this area. Data are provided in JPEG and CR2 formats.

Micrographs (photographs taken using a microscope) of xenoliths (pre-existing rock material included in younger rocks) in this area, to understand the formation of mineral deposits there. Data are provided in JPEG and CR2 formats.

U-Pb isotopic data collected on zircon in xenoliths from the Sliderock Mountain and Susie Peak plutons using the sensitive high-resolution ion microprobe-reverse geometry (SHRIMP-RG) at Stanford University. Data are provided in CSV format, locations are provided in shapefile format.

Scanned drill core logs and explanatory material provided in PDF format. Hand-written notes provided in CSV format. Locations provided in shapefile format.

Whole rock geochemical analysis of sulfide- and chromite-bearing samples in this area, with specific interest in PGE, cobalt, and gold concentrations. Data are provided in CSV format.

Bright phase and energy-dispersive spectroscopic analyses were performed to evaluate platinum-group element and mineral distribution in a variety of rock types from the lower stratigraphy of the Stillwater Complex in Montana. Data are provided in CSV format, supporting analytical data are provided as PDF reports and TIFF images.

Geologic structure strike and dip information from this area from pre-existing digital strike and dip information and from digitizing strike and dip locations from georeferenced map images. Data are provided in shapefile format.

Gravity measurements were collected during 2013, 2014, 2020 at 168 sites on and around the Stillwater layered mafic complex. Data are provided in CSV and shapefile formats.

Whole-rock major, minor, and trace element geochemistry of rock samples collected from diamond drill holes that intersect the textural discontinuity at the top of the Reef Package from the underground working of the Stillwater Mine. Data are provide in CSV format.

<p>The Stillwater Complex is a Neoarchean, ultramafic to mafic layered intrusion exposed in the Beartooth Mountains in south-central Montana. This igneous intrusion contains magmatic mineralization that is variably enriched in strategic and critical commo

Chemistry and geologic information for historic ore and ore-related rock samples from mineral deposits in the United States and from archetypal deposits from 27 other countries. Data are provide in Microsoft Access, Microsoft Excel, and CSV formats.

Airborne electromagnetic and magnetic survey data were collected during 2016 along 4,212 line-kilometers over this area. The survey was flown with a nominal line spacing of 450 meters or less, and mean flight height about 48 m providing depth of investigation about 500m. Data are provided in CSV format, flight lines in shapefile format.

Airborne electromagnetic (AEM) and magnetic survey data were collected in 2016 along 4,212 line-kilometers over this area as part of a study of the subsurface geologic structure and geothermal and groundwater resources of Yellowstone National Park. Data are provided in CSV format.

Results of mineral abundance estimates based on Rietveld refinement of X-ray diffraction (XRD) analyses of mill tailings and other ore processing materials from worldwide localities. Data are provided in CSV format.

Historical context of minerals exploration in this area including the locations of drill cores and lithologic, structural, grain size, and chromite, sulfide, copper, and nickel mineralization. Data are provided in TIFF images, with originally hand written information provided in CSV format, and location information as shapefiles.

Photomicrographs, lithologic and textural information for drill core from this area to study contact-type mineralization that occurs near the lower contact (Basal series and hornfels rocks) of the complex. Data are provided as JPG and CR2 images.

Images of graphic drill core logs showing associated drill core information, explanation for the lithology and structure sections of the logs, locations of the drill holes, and tabular data compiled from handwritten notes on the logs. Data are provided in TIFF, shapefile, and CSV formats.

Photographic images of thin sections of drill core from this area to study contact-type copper and nickel sulfide mineralization there. Data are provided in JPEG and CR2 formats, with a shapefile giving locations of the cores.

Photographs and micrographs of hand samples and drill core from this area to study platinum-group element reef-type mineralization that occurs in the J-M Reef of the Stillwater Complex. Data are provided in JPEG and CR2 formats.

Scanned drill core logs and explanatory material provided in PDF format. Hand-written notes provided in CSV format. Locations provided in shapefile format.

Geochemical analyses of solid mill tailings and other ore processing materials from worldwide localities, and leachates from those samples. Data are provided in CSV format.

Images of graphic drill core logs showing associated drill core information, an image of the explanation for the lithology and structure sections of the logs, the locations of the drill holes, and tabular data compiled from handwritten drill core logs. Data are provided in TIFF and CSV formats.

Scanned images of graphic drill core logs showing associated drill core information, explanatory information, and tabular data drawn from handwritten notes on the logs. Data are provided in TIFF and CSV formats.

U-Pb zircon data and geochronology for Proterozoic rocks in this area to better understand the tectonic evolution of the area. Samples are from drill cores, part of a larger characterization of the age and geochemical character of basement terranes in the United States. Data are provided in CSV format.