The West Fork East Adit is a rhodium, palladium, and platinum mine located in Sweet Grass county, Montana at an elevation of 6,650 feet.
About the MRDS Data:
All mine locations were obtained from the USGS Mineral Resources Data System. The locations and other information in this database have not been verified for accuracy. It should be assumed that all mines are on private property.
Mine Info
Elevation: 6,650 Feet (2,027 Meters)
Commodity: Rhodium, Palladium, Platinum
Lat, Long: 45.39889, -109.96806
Map: View on Google Maps
Satelite View
MRDS mine locations are often very general, and in some cases are incorrect. Some mine remains have been covered or removed by modern industrial activity or by development of things like housing. The satellite view offers a quick glimpse as to whether the MRDS location corresponds to visible mine remains.
West Fork East Adit MRDS details
Site Name
Primary: West Fork East Adit
Secondary: J-M Reef
Commodity
Primary: Rhodium
Primary: Palladium
Primary: Platinum
Secondary: Gold
Tertiary: Copper
Tertiary: Nickel
Location
State: Montana
County: Sweet Grass
District: In Stillwater Complex
Land Status
Land ownership: National Forest
Note: the land ownership field only identifies whether the area the mine is in is generally on public lands like Forest Service or BLM land, or if it is in an area that is generally private property. It does not definitively identify property status, nor does it indicate claim status or whether an area is open to prospecting. Always respect private property.
Holdings
Not available
Workings
Not available
Ownership
Owner Name: Johns-Manville Products Corp.
Years: 1977 -
Production
Not available
Deposit
Record Type: Site
Operation Category: Occurrence
Operation Type: Unknown
Discovery Year: 1967
Years of Production:
Organization:
Significant: N
Deposit Size: S
Physiography
General Physiographic Area: Rocky Mountain System
Physiographic Province: Middle Rocky Mountains
Mineral Deposit Model
Model Name: Merensky Reef PGE
Orebody
Form: STRATIFORM, DISSEMINATED
Structure
Type: R
Description: The Stillwater Complex Is Exposed Along The Northern Margin Of The Beartooth Uplift, One Of Several Laramide Basement-Cored Ranges That Make Up The Rocky Mountain Foreland Of South-Central Montana (Foose And Others, 1961: Kulik And Schmidt, 1988)
Alterations
Not available
Rocks
Name: Norite
Role: Host
Age Type: Host Rock
Age Young: Early Cretaceous
Name: Norite
Role: Host
Age Type: Associated Rock Unit
Age Young: Neoarchean
Analytical Data
Analytical Data: AVERAGE GRADE OF 14.7 PPM PT+PD, 0.15% CU+NI ACROSS 1.9 M OVER A STRIKE LENGTH OF 657 M. PT:PD=3.5
Materials
Ore: Pentlandite
Ore: Chalcopyrite
Ore: Pyrrhotite
Ore: Pyrite
Gangue: Chlorite
Gangue: Magnetite
Gangue: Hornblende
Gangue: Olivine
Gangue: Plagioclase
Gangue: Pyroxene
Gangue: Phlogopite
Gangue: Apatite
Gangue: Serpentine
Gangue: Talc
Gangue: Tremolite
Comments
Comment (Location): UNSURVEYED. IN CUSTER NATIONAL FOREST. ADIT SHOWN ON SEGERSTROM AND CARLSON
Comment (Deposit): THE J-M REEF IS 400-450 M ABOVE THE BASE OF THE BANDED SERIES IN BASAL PART OF ANORTHOSITE I SUBZONE OF TROCTOLITE-ANORTHOSITE ZONE I. THIS COINCIDES WITH THE REAPPEARANCE OF OLIVINE IN THE CRYSTALLIZATION SEQUENCE.
Comment (Workings): ADIT
Comment (Geology): J-M REEF IS 1-3 M THICK AND CAN BE TRACED FOR 40 KM. AGE OF STILLWATER COMPLEX IS 2,705 +/- 4 MA BASED ON U-PB SYSTEMATICS ON ZIRCON-BADDELEYITE (PREMO AND OTHERS, 1990)
References
Reference (Deposit): ZIENTEK, M.L., 1993, MINERAL RESOURCE APPRAISAL FOR LOCATABLE MINERALS: THE STILLWATER COMPLEX, IN HAMMARSTROM, J.M., ZIENTEK, M.L., AND ELLIOTT, J.E., EDS., MINERAL RESOURCE ASSESSMENT OF THE ABSAROKA-BEARTOOTH STUDY AREA, CUSTER AND GALLATIN NATIONAL FORESTS, MONTANA: U.S. GEOLOGICAL SURVEY OPEN-FILE REPORT 93-207, P. F1-F83.
Reference (Deposit): CONN, H.K., 1979, THE JOHNS-MANVILLE PLATINUM-PALLADIUM PROSPECT, STILLWATER COMPLEX, MONTANA, U.S.A.: CANADIAN MINERALOGIST, V. 17, P. 463-468.
Reference (Deposit): SEGERSTROM, KENNETH, AND CARLSON, R.R., 1982, GEOLOGIC MAP OF THE BANDED UPPER ZONE OF THE STILLWATER COMPLEX AND ADJACENT ROCKS, STILLWATER, SWEET GRASS, AND PARK COUNTIES, MONTANA: U.S. GEOLOGICAL SURVEY MISCELLANEOUS GEOLOGIC INVESTIGATIONS MAP I-1383, SCALE 1:24,000.
Reference (Analytical Data): CONN, 1979
Reference (Deposit): PREMO, W.R., HELZ, R.T., ZIENTEK, M.L., AND LANGSTON, R.B., 1990, U-PB AND SM-ND AGES FOR THE STILLWATER COMPLEX AND ITS ASSOCIATED SILLS AND DIKES, BEARTOOTH MOUNTAINS, MONTANA: IDENTIFICATION OF A PARENT MAGMA?: GEOLOGY, V. 18, P. 1065-1068.
Principal Gold Districts of Montana
In Montana, 54 mining districts have each have produced more than 10,000 ounces of gold. The largest producers are Butte, Helena, Marysville, and Virginia City, each having produced more than one million ounces. Twenty seven other districts are each credited with between 100,000 and one million ounces of gold production. Read more: Principal Gold Districts of Montana.
