Mouat Ni-Cu South

Stillwater County, Montana, United States

CopperNickelCobaltPGESilverGold

⌖ Show on map USGS source ↗

Commodities

PrimaryCopper, Nickel

SecondaryCobalt

TertiaryPGE, Silver, Gold

Commodity typeM

Deposit

Model1: Stillwater Ni-Cu

Deposit sizeN

Orebody formLENTICULAR TO TABULAR CONCENTRATIONS OF SUFLIDE MINERALS

Ore controlImnmiscible Sulfide Liquid Enriched In Ni And Cu Exsolved From Mafic Silicate Magma And Accumulated Near The Lower Contact Of The Stillwater Complex. Assimilation Of Sulfur From Rocks Adjacent To The Stillwatr Complex May Have Led To The Exsolution Of The Sulfide Liquid (Zientek And Ripley, 1990)

Materials

Ore mineralsChalcopyrite, Pentlandite, Pyrrhotite

GangueMagnetite, Olivine, Plagioclase

Geology

Host rockPeridotite · Stillwater Complex, Ultramafic Series, Peridotite Zone;Stillwater Complex, Basal Series;Stillwater Complex;

StructureThe 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), See Deposit Description

Tectonic settingThe 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 Which 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

AlterationNone Related To The Ore-Forming Process

Economic & production

Development statusOccurrence

Discovery year1967

Identification

Deposit ID10048658

MRDS IDMP00270

Alternate namesSouth Mouat Area

RegionNA

Data scoreB

Coordinates45.37686, -109.89996

References

ATTANASI, E.D., AND BAWIEC, W.J., 1987, A RESOURCE ASSESSMENT OF COPPER AND NICKEL SULFIDES WITHIN THE MOUNTAIN VIEW AREA, STILLWATER COMPLEX, MONTANA: U.S. GEOLOGICAL SURVEY BULLETIN 1674B, 29 P.PAGE, N.J, 1979, STILLWATR COMPLEX, MONTANA - STRUCTURE, MINERALOGY, AND PETROLOGY OF THE BASAL ZONE WITH EMPHASIS ON THE OCCURRENCE OF SULFIDES: U.S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 1938, 69 P.PAGE, N.J, ZIENTEK, M.L., LIPIN, B.R., MANN, E.L. (BOB), SCHMIDT, E.A., TURNER, A.R., CZAMANSKE, G.K., AND RAEDEKE, L.D., 1985B, EXPLORATION AND MINING HISTORY OF THE STILLWATER COMPLEX AND ADJACENT ROCKS, IN CZAMANSKE, G.K., AND ZIENTEK, M.L., EDS., THE STILLWATER COMPLEX, MONTANA: GEOLOGY AND GUIDE: MONTANA BUREAU OF MINES AND GEOLOGY SPECIAL PUBLICATIONS 92, P. 77-92.PAGE, N.J, ZIENTEK, M.L., LIPIN, B.R., RAEDEKE, L.D., WOODEN, J.L., TURNER, A.R., LOFERSKI, P.J., FOOSE, M.P., MORING, B.C., AND RYAN, M.P., 1985A, GEOLOGY OF THE STILLWATER COMPLEX EXPOSED IN THE MOUNTAIN VIEW AREA AND ON THE WEST SIDE OF THE STILLWATER CANYON, IN CZAMANSKE, G.K., AND ZIENTEK, M.L., EDS., THE STILLWATER COMPLEX, MONTANA: GEOLOGY AND GUIDE: MONTANA BUREAU OF MINES AND GEOLOGY SPECIAL PUBLICATION 92, P. 147-209.PAGE, N.J, AND NOKLEBERG, W.J., 1974, GEOLOGIC MAP OF THE STILLWATER COMPLEX, MONTANA: U.S. GEOLOGICAL SURVEY MISCELLANEOUS GEOLOGIC INVESTIGATIONS SERIES MAP I-797, 5 SHEETS, SCALE 1:12,000.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.WOODEN, J.L., CZAMANSKE, G.K., AND ZIENTEK, M.L., 1991, A LEAD ISOTOPIC STUDY OF THE STILLWATER COMPLEX, MONTANA: CONSTRAINTS ON CRUSTAL CONTAMINATION AND SOURCE REGIONS: CONTRIBUTIONS TO MINERALOGY AND PETROLOGY, V. 107, P. 80-93.ZIENTEK, M.L., AND RIPLEY, E.M., 1990, SULFUR ISOTOPIC STUDIES OF THE STILLWATER COMPLEX AND ASSOCIATED ROCKS, MONTANA: ECONOMIC GEOLOGY, V. 85, P. 376-391.ZIENTEK, M.L., BAWIEC, W.J., PAGE, N.J, AND COOPER, R.W., 1989, MAPS, SECTIONS, AND STRUCTURE-CONTOUR PERSPECTIVE DIAGRAMS SHOWING THE GEOLOGY AND GEOCHEMISTRY OF THE MOUAT NICKEL-COPPER PROSPECT, STILLWATER COMPLEX, STILLWATER COUNTY, MONTANA: U.S. GEOLOGICAL SURVEY MISCELLANEOUS FIELD STUDIES MAP MF-2038, 2 SHEETS, SCALE 1:24,000.ZINETEK, 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 ABASROKA-BEARTOOTH STUDY AREA, CUSTER AND GALLATIN NATIONAL FORESTS, MONTANA: U.S. GEOLOGICAL SURVEY OPEN-FILE REPORT 93-207, P. F1-F83.ZIENTEK, M.L., FOOSE, M.P., AND MEI, LEUNG, 1986, PALLADIUM, PLATINUM, AND RHODIUM CONTENTS OF ROCKS NEAR THE LOWER MARGIN OF THE STILLWATER COMPLEX, MONTANA: ECONOMIC GEOLOGY, V. 81, P. 1169-1178.SOUTH MOUAT AREA RESOURCE ESTIMATES ARE FROM ATTANASI AND BAWIEC (1987) AND WERE MADE ON TWO DOMAINS; THE FIRST FOUR ESTIMATES ABOVE FROM ONE DOMAIN AND THE LAST OUR FROM THE OTHER DOMAIN