Mine detail: Benbow Mine

Previously called ''

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Location

Lat / long: 45.36436, -109.8069

Resource(M)

Primary: Chromium
Tertiary: Platinum, Palladium, Rhodium
Ore: Chromite
Gangue: Olivine, Serpentine
Orebody form: MASSIVE BANDS AND DISSEMINATED
Discovery year: 1905

Production

Operation type: Unknown
Production size: Small
Development status: Past Producer
First production started: 1941

Geology

Host type:Harzburgite
Associated rock:Stillwater Complex, Ultramafic Series
Associated type:Quartz Monzonite,Mafic Intrusive Rock
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) ; Reg.Trends: Strike Of Ultramafic Zone: N60 Deg. W-N 80 Deg.W, Numerous Small Faults Striking Northward
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
Alteration processes:Some Serpentinization Of Harzburgite

References

MRDSM060101
DEP10042346
Reference{Deposit:: WIMMLER, N.L., 1948, INVESTIGATION OF CHROMITE DEPOSITS OF THE STILLWATER COMPLEX, STILLWATER AND SWEETGRASS COUNTIES, MONT.: U.S. BUREAU OF MINES REPORT OF INVESTIGATIONS 4368, P. 16-19.}{Deposit:: PEOPLES, J.W., AND HOWLAND, A.L., 1940, CHROMITE DEPOSITS OF THE EASTERN PART OF THE STILLWATER COMPLEX, STILLWATER COUNTY, MONTANA: U.S. GEOLOGICAL SURVEY BULLETIN 922-N, P. 371-411.}{Deposit:: JACKSON, E.D., 1968, THE CHROMITE DEPOSITS OF THE STILLWATER COMPLEX, MONTANA, IN RIDGE, J.D., ED., ORE DEPOSITS OF THE UNITED STATES,1933/1967, GRATON-SALES VOLUME: NEW YORK, AMERICAN INSTITUTE OF MINING, METALLURGICAL, AND PETROLEUM ENGINEERS, P. 1495-1510.}{Deposit:: PAGE, N.J, RILEY, L.B., AND HAFFTY, JOSEPH, 1969, PLATINUM, PALLADIUM, AND RHODIUM ANALYSES OF ULTRAMAFIC AND MAFIC ROCKS FROM THE STILLWATER COMPLEX, NMONTANA: U.S. GEOLOGICAL SURVEY CIRCULAR 624, 12 P.}{Deposit:: PAGE, N.J, RILEY, L.B., AND HAFFTY, JOSEPH, 1972, VERTICAL AND LATERAL VARIATION OF PLATINUM, PALLADIUM, AND RHODIUM IN THE STILLWATER COMPLEX, MONTANA: ECONOMIC GEOLOGY, V. 67, P. 918.}{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:: PAGE, N.J, AND DOHRENWEND, J.C., 1973, MINERAL RESOURCE POTENTIAL OF THE STILLWATER COMPLEX AND ADJACENT ROCKS IN THE NORTHERN PART OF THE MOUNT WOOD AND MOUNT DOUGLAS QUADRANGLES, SOUTHWESTERN MONTANA: U.S. GEOLOGICAL SURVY CIRCULAR 684, 9 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.}{Deposit:: 1939 DIREXPL USB}{Reserve-Resource:: PAGE AND OTHERS, 1972}
ReporterDohrenwend, John C., Berg, Richard B. (Krohn, D. H.), Peterson, Jocelyn A.