Mine detail: Blakely Cliffs

<< Back to the map

<< Back to browsing

Location:	Sweet Grass County, Montana, United States, North America
Lat / long:	45.45659, -110.1683
dep_id:	10048026
mrds_id:	M700434
Commodity type:	metallic
Major mineral:	Chromium
Trace mineral:	PGE
Operation type:	Unknown
Production size:	No production occurred
Development status:	Occurrence
ore:	Chromite
gangue:	Olivine
orebody_fm:	MASSIVE LAYERS, DISSEMINATED
model:	2: Bushveld Cr
conc_proc:	Magmatic Segregation, Crystal Settling
ore_ctrl:	Crystal Settling In Large Magma Chamber
Reporter:	Dohrenwend, John C., Doyle, Brien (Wells, John), Peterson, Jocelyn A.
hrock_type:	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), Small 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:	Deposit:: HOWLAND, A.L., GARRELS, E.M., AND JONES, W.R., 1949, CHROMITE DEPOSITS OF BOULDER RIVER AREA, SWEETGRASS COUNTY, MONTANA: U.S. GEOLOGICAL SURVEY BULLETIN 948-C, P. 74. 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.