Mine detail: West Fork East Adit

Previously called 'J-M Reef'

Location:	Sweet Grass County, Montana, United States, North America
Lat / long:	45.39881, -109.96885
dep_id:	10048513
mrds_id:	MP00102
Commodity type:	metallic
Major mineral:	Platinum, Palladium, Rhodium
Minor mineral:	Gold
Trace mineral:	Copper, Nickel
Operation type:	Unknown
Production size:	No production occurred
Development status:	Occurrence
ore:	Chalcopyrite, Pentlandite, Pyrite, Pyrrhotite
gangue:	Apatite, Chlorite, Hornblende, Magnetite, Olivine, Phlogopite, Plagioclase, Pyroxene, Serpentine, Talc, Tremolite
orebody_fm:	STRATIFORM, DISSEMINATED
model:	4: Merensky Reef PGE
ore_ctrl:	Magma Mixing
Reporter:	Peterson, Jocelyn A.
hrock_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)
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
disc_yr:	1967
discr:	Johns-Manville
References:	Analytical Data:: CONN, 1979 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. 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:: 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:: CONN, H.K., 1979, THE JOHNS-MANVILLE PLATINUM-PALLADIUM PROSPECT, STILLWATER COMPLEX, MONTANA, U.S.A.: CANADIAN MINERALOGIST, V. 17, P. 463-468.