Previous mineral resource assessment data compilation for the U.S. Geological Survey Sagebrush Mineral Resource Assessment Project

This data release consists of a compilation of previously published mineral potential maps that were used for the Sagebrush Mineral Resource Assessment (SaMiRA) project. This information was used as guides for assessing mineral potential assessment of approximately 10 million acres in Idaho, Montana, Nevada, Utah, and Wyoming. Specifically, the compilation was used to identify the deposit types to be assessed and the deposit models to develop. The data release consists of georeferenced images of mineral potential maps and vector shapefiles of mineral potential tracts. The georeferenced images are presented in two formats: 1) as images within raster mosaic datasets in Esri geodatabases, and 2) as individual tiff images with an accompanying data Excel table. There are four geodatabases containing the raster mosaic datasets, one for each of the four SaMiRA report areas: North-Central Montana; North-Central Idaho; Southwestern and South-Central Wyoming and Bear River Watershed; and Nevada Borderlands. Tract map images are from BLM and Forest Service wilderness study summary reports, along with multiple other mineral potential reports that were done under the USGS CUSMAP program and for USGS assessments of USGS National Forests. The georeferenced images were clipped to the extent of the map and all explanatory text, gathered from map explanations or report text was imported into the raster mosaic dataset database as Footprint layer attributes. This data is also included as an Excel table, which can be used in conjunction with the individual georeferenced tiff images. The data compiled into the tables contains the figure caption from the original map, online linkage to the source report when available, and information on the assessed commodities according to the legal definition of mineral resourcesmetallic, non-metallic, leasable non-fuel, leasable fuel, geothermal, paleontological, and saleable. The shapefiles were compiled from datasets which had different data structure schemes and which used two different types of assessment methodology. The BLM used qualitative categorical and others used the USGS quantitative 3-part form of assessment. The original GIS data was re-formatted so that all of the shapefiles had one of two consistent attribute table structures, one for reports that had quantitative data, and one for reports with qualitative data. A general attribute table structure was created which contained fields for information on the deposit type assessed, assessment rank, type of assessment, and tract name and identifier. For the attribute table of the quantitatively assessed reports which used the USGS 3-part form of assessment, we added additional fields for the deposit model name and number, probabilistic assessment results data, and estimators. We captured the original information as presented but also standardized nomenclature when we could and referred to the report text in some instances in order to fill in missing data into the descriptive data tables.