Mine detail: Big Seven Mine

Previously called ''

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Location

Lat / long:

46.94908, -110.70556

Resource(M)

Primary:	Silver, Gold
Secondary:	Copper, Lead
Tertiary:	Molybdenum, Zinc
Ore:	Chalcopyrite, Freibergite, Galena, Molybdenite, Proustite, Pyrite, Sphalerite
Orebody form:	TABULAR
Discovery year:	1892

Production

Operation type:	Unknown
Deposit type:	Polymetallic veins
Production size:	Yes
Development status:	Past Producer

Geology

Host rock:	Belt, Neihart Quartzite;Gneiss And Schist
Host type:	Diorite,Quartzite,Gneiss,Rhyolite
Associated rock:	Snow Creek Porphyry-Pluton And Dikes Of Rhyolite Porphyry;Pinto Diorite-Large Phenocrysts Of Feldspar & Hornblende
Associated type:	Diorite,Rhyolite
Structure:	Zone Of Igneous Intrusions Covering Over 800 Square Km., Domal Uplift Caused By Intrusion Of Snow Creek Porphyry, Northeast-Trending Fractures And Faults
Tectonic:	Rocky Mountain Foreland
Alteration processes:	Sericitization & Silicification

References

MRDS	W014726
DEP	10071381
Reference	{Deposit:: ROBERTSON, A. F., 1951, MINES & MINERAL DEPOSITS - CASCADE COUNTY, MONTANA, U.S. BUREAU MINES INF. CIRC. 7589.}{Deposit:: SCHAFER, P. A., 1935, GEOLOGY AND ORE DEPOSITS - NEIHART MINING DISTRICT, CASCADE CO., MONTANA, MT BUREAU OF MINES & GEOLOGY MEM. 13}{Deposit:: KLEINKOPF, M. D., WITKIND, I. J., AND KEEFER, W. R., 1972, AEROMAGNETIC, BOUGUER GRAVITY, AND GENERLIZED GEOLOGIC MAPS OF THE CENTRAL PART OF THE LITTLE BELT MOUNTAINS, MONTANA: U.S. GEOLOGICAL SURVEY MAP GP-837}{Geology:: WEED, W.H., 1900, THE GEOLOGY OF THE LITTLE BELT MOOUNTAINS, MONTANA: U.S. GEOLOGICAL SURVEY TWENTIETH ANNUAL REPORT, PART 3, P. 437-439.}{Production:: ROBERTSON, 1951, U.S.B.M. INF. CIRC. 7589}
Reporter	Mlynarczyk, Meg S.