| Location: | Sweet Grass County, Montana, United States, North America |
| Lat / long: | 45.44936, -110.05108 |
| dep_id: | 10048501 |
| mrds_id: | MP00090 |
| Commodity type: | metallic |
| Major mineral: | Platinum, Palladium |
| Minor mineral: | Copper, Nickel |
| Trace mineral: | Cobalt, Iridium, Gold, Arsenic, Antimony |
| Operation type: | Unknown |
| Production size: | No production occurred |
| Development status: | Occurrence |
| ore: | Chalcopyrite, Pentlandite, Pyrite, Pyrrhotite, Sperrylite |
| gangue: | Apatite, Calcite, Chlorite, Graphite, Magnetite, Plagioclase, Quartz, Talc |
| orebody_fm: | LENSES, PODS, PIPES, DISSEMINATED |
| alteration: | Plagioclase Is Altered To Clinozoisite-Epidote, Pyroxene To Chlorite-Calcite-(Talc)- Magnetite-Quartz, Pyrrhotite To Pyrite |
| conc_proc: | Late Stage Concentration Of Sulfide |
| ore_ctrl: | Crystallization Processes Within Anorthosite |
| Reporter: | Peterson, Jocelyn A. |
| hrock_type: | Anorthosite |
| 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), Cross Faults Offset Sulfide Bearing Zone |
| 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 |
| dy_ba: | < |
| disc_yr: | 1936 |
| References: |
- Deposit:: BOUDREAU, A.E., AND MCCALLUM, I.S., 1986, INVESTIGATIONS OF THE STILLWATER COMPLEX: III. THE PICKET PIN PT/PD DEPOSIT: ECONOMIC GEOLOGY, V. 81, P. 1953-1975.
- 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:: HOWLAND, A.L., PEOPLES, J.W., AND SAMPSON, EDWARD, 1936, THE STILLWATER IGNEOUS COMPLEX AND ASSOCIATED OCCURRENCES OF NICKEL AND PLATINUM GROUP METALS: MONTANA BUREAU OF MINES AND GEOLOGY MISCELLANEOUS CONTRIBUTION 7, 15 P.
- 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.
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