Chemistry and geologic information for nearly 30,000 historic ore and ore-related rock samples from mineral deposits and mining districts in the United States. Data are provided in Microsoft Access and CSV formats.

Geochemical data from selected USGS projects from the 1960s-1980s that were previously not published as digital data. Includes geochemical analyses from 36,498 samples of various types using analytical methods and instruments that were current when those studies were carried out. Data are provided in Microsoft Access, shapefile, and CSV formats.

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

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.

Resource assessment and supporting data including permissive tracts, mineral sites in the study area, geologic units, geologic maps, stream sediment geochemistry, whole rock chemistry, airborne radiometric data, and lower frequency content EMAG2 data. Data are provided in Esri file geodatabase, shapefile, and CSV formats.