Missoula barite (Elk Creek-Coloma District)

Region West, Northwest
Mineral systems
Deposit types
Critical minerals
Other minerals

Information leading to the delineation of this focus area

Basis for focus area Outline of a cluster of barite mines and occurrences in southeastern Missoula County, including the Elk Creek (Greenough) mine.
Identified resources Historical production of barite.
Production Greenough mine (1951-1956): total production was approximately 90,000 tons barite (Clawson, 1957). Cumulative production continued until 1988, with production between 150,000 to 200,000 tons barite (Berg, 1990).
Status Past mining.
Estimated resources Unknown.
Geologic maps Weber and Witkind (1979a, b), scale 1:24,000; Lewis (1998a), scale 1:250,000.
Geophysical data Inadequate Rank 3 to 4 aeromagnetic and Rank 4 aeroradiometric coverage.
Favorable rocks and structures Precambrian Missoula Group. Veins occur within 1.2 miles of the exposed contact of the Cretaceous granitoid Garnet stock (Berg, 1990).
Deposits Greenough (Elk Creek) mine (MRDS dep_id: 10221988), Fands mine.
Evidence from mineral occurrences MRDS.
Geochemical evidence No data.
Geophysical evidence Unknown.
Evidence from other sources None.
Comments Veins are in the Garnet Range Formation near its contact with Cretaceous plutons. The Elk Creek vein is at maximum 27 ft thick but averages 7 ft thick (Berg, 1990). The deposits follow the contact between a Cretaceous pluton and older Belt rocks, suggesting magmatic origins.
Cover thickness and description Exposed at the surface and extends to unknown depth.
Authors Jane M. Hammarstrom, Kaleb C. Scarberry, Jay A. Gunderson.
New data needs Geologic mapping, geophysical and geochemical surveys.
Geologic mapping and modeling needs No mapping at larger scale than 1:100,000 scale is available. 1:24,000 scale quadrangle mapping would help better understand the geologic environment and potential of these deposits.
Geophysical survey and modeling needs High resolution aeromagnetic and aeroradiometric coverage.
Digital elevation data needs Lidar complete for the Bitterroot Valley and in progress for the adjacent ranges; in progress.