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A geologic and mineral exploration spatial database for the Stillwater Complex, Montana

October 31, 2014

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 commodities such as chromium, nickel, and the platinum-group elements. One deposit, the J-M Reef, is the sole source of primary production and reserves for platinum-group elements in the United States.


A large amount of information has been collected on the Stillwater Complex. In the 1930s, academics, the U.S. Geological Survey, and the [U.S.] Bureau of Mines initiated geologic investigations on the Stillwater Complex. Since that time, more than 600 publications on the Stillwater Complex have appeared in the scientific literature. Exploration and mining companies have collected even more information since the 1920s.


This report provides essential spatially referenced datasets based on geologic mapping and mineral exploration activities conducted from the 1920s to the 1990s. This information will facilitate research on the complex and provide background material needed to explore for mineral resources and to develop sound land-management policy.

Citation Information

Publication Year 2014
Title A geologic and mineral exploration spatial database for the Stillwater Complex, Montana
DOI 10.3133/sir20145183
Authors Michael L. Zientek, Heather L. Parks
Publication Type Report
Publication Subtype USGS Numbered Series
Series Title Scientific Investigations Report
Series Number 2014-5183
Index ID sir20145183
Record Source USGS Publications Warehouse
USGS Organization Geology, Minerals, Energy, and Geophysics Science Center