The Pumicestone Bay is a 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
Satelite View
MRDS mine locations are often very general, and in some cases are incorrect. Some mine remains have been covered or removed by modern industrial activity or by development of things like housing. The satellite view offers a quick glimpse as to whether the MRDS location corresponds to visible mine remains.
Pumicestone Bay MRDS details
Site Name
Primary: Pumicestone Bay
Commodity
Primary: Gold
Primary: Silver
Secondary: Lead
Secondary: Barium-Barite
Secondary: Zinc
Location
State: Alaska
District: Aleutians
Land Status
Not available
Holdings
Not available
Workings
Not available
Ownership
Not available
Production
Not available
Deposit
Record Type: Site
Operation Category: Prospect
Operation Type: Unknown
Years of Production:
Organization:
Significant:
Physiography
Not available
Mineral Deposit Model
Model Name: Epithermal vein, generic
Model Name: Polymetallic veins
Orebody
Not available
Structure
Not available
Alterations
Alteration Type: L
Alteration Text: Rocks are regionally propylitically altered and also hornfelsed as a result of proximity to the Shaler batholith (Simpson, 1986). Highest gold grades are associated with zones of 'pyrite-silica' alteration in 'spotted andesite' (Simpson, 1986).
Rocks
Not available
Analytical Data
Not available
Materials
Ore: Chalcopyrite
Ore: Galena
Ore: Pyrite
Ore: Sphalerite
Gangue: Chlorite
Gangue: Epidote
Gangue: Magnetite
Gangue: Specularite
Comments
Comment (Geology): Geologic Description = Christie (1974) reported a single 3,000 ft (900 m) by 1,500 ft (450 m) color anomaly whereas later evaluations by Randolph and Ellis (1989) and Randolph (1991) described three color anomalies aligned along a steep valley wall. Country rock is the Unalaska Formation (see Drewes and others, 1961), near a sheared contact with the Shaler batholith. Granodiorite of the pluton occurs below the color anomalies at elevations below about 600 feet (200 m). Prospect lies at contact with metamorphosed impure sandstone, breccia, and quartz pebble conglomerate. Stockwork veining and silicification is locally developed within an exposed volume of 1600 by 160 feet, having a 75 foot thickness (80 x 50 x 20 m). Semi-parallel northeast-trending shear zones cut off the quartz stockwork and silicification to the northwest. Quartz veining occurs parallel and/or marginal to these shear zones. Largest of these quartz veins is about 1 foot (30 cm) wide, gossanous, and contains up to 20 percent pyrite (Randolph, 1991) and rare chalcopyrite, sphalerite, and/or galena (Christie, 1974; Randolph, 1991). Randolph's (1991) interpretation was that there were two episodes of veining, where the sulfide-bearing shear-hosted veins cut the earlier quartz stockwork.
Comment (Geology): Age = Miocene or younger
Comment (Exploration): Status = Inactive
Comment (Workings): Workings / Exploration = Battle Mountain Exploration Co. (BMEC) established a sampling grid over one exposure of hornfelsed volcaniclastic rocks and/or graywacke that has been strongly stockworked and silicified. Quartz stringer densities were as high as 2 per inch (2.54 cm) and only rarely contain visible sulfides. The quartz stockwork contained gold to 272 ppb and slightly anomalous lead and barium. Quartz veins hosted in the northeast-trending shear zones contain up to 275 ppb gold, 31.5 ppm silver, 0.24 percent lead, 0.14 percent zinc, elevated barium and insignificant mercury and arsenic (Randolph, 1991).
Comment (Reference): Primary Reference = Randolph, 1991
Comment (Deposit): Model Name = Polymetallic vein, epithermal gold vein
Comment (Deposit): Model Number = 22c, 25
Comment (Deposit): Other Comments = Randolph (1991) gave the prospect a poor potential for economic gold mineralization due to remoteness, ruggedness of the environment, and minimal evidence for economic mineralization.
References
Reference (Deposit): Christie, J.S., 1974, Aleut-Quintana-Duval 1974 joint venture, final report: Unpublished Quintana Minerals Corporation report, 24 p., 3 appendices, 2 maps. (Report held by the Aleut Corporation, Anchorage, Alaska.)
Reference (Deposit): Randolph, D.B., and Ellis, W.T., 1989, Unalaska project, 1989 final report: Battle Mountain Exploration Company, Alaska District, 41 p., 5 appendices, 11 plates, various scales. (Report held by the Aleut Corporation, Anchorage, Alaska.)
Reference (Deposit): Drewes, Harold, Fraser, G.D., Snyder, G.L., and Barnett, H.F., Jr., 1961, Geology of Unalaska Island and adjacent insular shelf, Aleutian Islands, Alaska: U.S. Geological Survey Bulletin 1028-S, p. 583-676.
Reference (Deposit): Randolph, D.B., 1991, Unalaska project, 1990 final report: Battle Mountain Exploration Company, Alaska District, 62 p., 5 appendices, 15 plates, various scales. (Report held by the Aleut Corporation, Anchorage, Alaska.)
Reference (Deposit): Simpson, D.F., 1986, Aleutian Islands project, 1985 final report: Kennecott Alaska Exploration Company, 54 p. (Report held by the Aleut Native Corporation, Anchorage, Alaska.)
The Top Ten Gold Producing States
These ten states contributed the most to the gold production that built the West from 1848 through the 1930s. The Top Ten Gold Producing States.
