The Breccia (south of Snowcap Mountain) is a copper, gold, and silver mine located in Alaska.
About the MRDS Data:
All mine locations were obtained from the USGS Mineral Resources Data System. The locations and other information in this database have not been verified for accuracy. It should be assumed that all mines are on private property.
Mine Info
Breccia (south of Snowcap Mountain) MRDS details
Site Name
Primary: Breccia (south of Snowcap Mountain)
Commodity
Primary: Copper
Primary: Gold
Primary: Silver
Secondary: Bismuth
Location
State: Alaska
District: McGrath
Land Status
Not available
Holdings
Not available
Workings
Not available
Ownership
Not available
Production
Not available
Deposit
Record Type: Site
Operation Category: Occurrence
Operation Type: Unknown
Years of Production:
Organization:
Significant:
Physiography
Not available
Mineral Deposit Model
Not available
Orebody
Not available
Structure
Not available
Alterations
Alteration Type: L
Alteration Text: Tourmaline replacement and veining.
Rocks
Not available
Analytical Data
Not available
Materials
Ore: Arsenopyrite
Ore: Chalcopyrite
Ore: Galena
Ore: Pyrite
Ore: Pyrrhotite
Ore: Sphalerite
Gangue: Calcite
Gangue: Chlorite
Gangue: Epidote
Gangue: Quartz
Gangue: Sericite
Gangue: Tourmaline
Comments
Comment (Reference): Primary Reference = Gamble and others, 1989
Comment (Workings): Workings / Exploration = Reconnaissance sampling has been done in this area (Gamble and others, 1989).
Comment (Deposit): Model Name = Tourmaline-cemented breccia in granitic rocks
Comment (Geology): Geologic Description = A tourmaline-cemented breccia as much as 80 feet across is present in monzogranite at this locality (Gamble and others, 1989). The breccia, includes vein quartz, light-colored angular rock fragments, and monzogranite clasts to about 3 feet across suspended in a black tourmaline matrix that also contains lesser amounts of sericite, quartz, calcite, and chlorite. Discontinuous quartz-tourmaline-sulfide veins to a foot wide cut the breccia along vertical, north-south-trending fractures. Sulfides in the veins include arsenopyrite, chalcopyrite, pyrrhotite, pyrite, and lesser amounts of galena and sphalerite; gangue minerals include quartz, tourmaline, chlorite, and epidote. A composite grab sample of 5 veins in the breccia contains as much as 4.1 ppm gold, 7 ppm silver,and greater than 2,000 ppm arsenic. Selected sulfide-rich samples contain as much as 21 ppm gold, 150 ppm silver, 10,000 ppm copper, and greater than 2,000 ppm arsenic and 1,000 ppm bismuth (Gamble and others, 1989).
Comment (Geology): Age = Cretaceous or Tertiary the breccia and veins crosscut granitic rocks that may be Late Cretaceous or Tertiary parts of the Alaska-Aleutian Range batholith.
Comment (Exploration): Status = Inactive
References
Reference (Deposit): Gamble, B.M., Bailey, E. A., and Reed, B. L., 1989, Gold occurrences near Snowcap Mountain, Lime Hills B-2 quadrangle, Alaska: U.S. Geological Survey Open-File Report 89-0646, 8 p.
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