Mine detail: Stillwater Mine

Previously called 'J-M ReefMinneapolis Adit'

<< Back to the map

Location

Lat / long:

45.38881, -109.8719

Resource(M)

Primary:	Palladium, Platinum
Secondary:	Rhodium, Gold
Tertiary:	Copper, Nickel
Ore:	Chalcopyrite, Pentlandite, Pyrite, Pyrrhotite
Gangue:	Apatite, Chlorite, Hornblende, Magnetite, Olivine, Phlogopite, Plagioclase, Serpentine, Talc, Tremolite
Orebody form:	STRATIFORM, DISSEMINATED
Discovery year:	1974

Production

Operation type:	Unknown
Production size:	Yes
Development status:	Producer
Production years:	1987-PRESENT
First production started:	1987

Geology

Host type:	Norite,Troctolite,Anorthosite,Harzburgite
Structure:	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), High-Angle Reverse Faults
Tectonic:	Tectonic Setting At Time Of Emplacement Of The Stillwater Complex Is Unknown. The Complex Was Emplaced Shortly After A Major Regional, Subduction-Related Magmatic Event That Culminated In Emplacement Of The 2.73-2.79 Ga Granitoid Suite In The Batholith Exposed In The Beartooth Uplift (Wooden And Others, 1991). However, There Is No Evidence That The Magmatism That Formed The Stillwater Complex Is Related To Convergent Margin Tectonics And Magmatism

References

MRDS	MP00087
DEP	10048498
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.}{Deposit:: TODD, S.G., KEITH, D.W., LE ROY, L.W., SCHISSEL, D.J., MANN, E.L., AND IRVINE, T.N., 1982, THE J-M PLATINUM-PALLADIUM REEF OF THE STILLWATER COMPLEX, MONTANA: I. STRATIGRAPHY AND PETROLOGY: ECONOMIC GEOLOGY, V. 77, P. 1454-1480.}{Deposit:: BOW, C., WOLFGRAM, D., TURNER, A., BARNES, S., EVANS, J., ZDEPSKI, M., AND BOUDREAU, A., 1982, INVESTIGATIONS OF THE HOWLAND REEF OF THE STILLWATER COMPLEX, MINNEAPOLIS ADIT AREA: STRATIGRAPHY, STRUCTURE, AND MINERALIZATION: ECONOMIC GEOLOGY, V. 77, P. 1481-1492.}{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.}{Deposit:: COOMBES, J.S., 1990, PLATINUM 1990: JOHNSON MATTHEY, P. 18.}{Production:: COOMBES, 1990}
Reporter	Peterson, Jocelyn A.