The Unnamed (east of inner Sylburn Harbor) is a copper 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
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Unnamed (east of inner Sylburn Harbor) MRDS details
Site Name
Primary: Unnamed (east of inner Sylburn Harbor)
Commodity
Primary: Copper
Location
State: Alaska
District: Ketchikan
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
Model Name: Polymetallic veins
Orebody
Not available
Structure
Not available
Alterations
Alteration Text: Local oxidation of chalcopyrite to azurite and malachite; oxidation of iron mineral(s) to hematite; sericitization of sheared trondhjemite country rock; sulfide impregnation of wallrock adjacent to veins.
Rocks
Not available
Analytical Data
Not available
Materials
Ore: Azurite
Ore: Chalcopyrite
Ore: Hematite
Ore: Magnetite
Ore: Malachite
Ore: Pyrite
Gangue: Calcite
Gangue: Quartz
Comments
Comment (Workings): Workings / Exploration = Of 63 rock samples collected from 1969-1975 by private interests, 8 had Cu values of more than 200 ppm, and 8 had Zn values of more than 200 ppm (Karl, 1992). One sample of a chalcopyrite-bearing quartz vein contained 6900 ppm Cu. Karl's (1992) samples of sulfide-bearing trondhjemite contained as much as 5500 ppm Cu; and a sample of a quartz-calcite-sulfide vein contained 0.08 ppm Au and 15,000 ppm Cu.
Comment (Reference): Primary Reference = Karl, 1992
Comment (Deposit): Model Name = Polymetallic veins (Cox and Singer, 1986; model 22c)
Comment (Geology): Geologic Description = The country rock in the area of this site is Silurian trondhjemite that was regionally metamorphosed to greenschist grade in Late Cretaceous time (Berg, 1972). The mineral occurrences consist of quartz-carbonate fissure veins in sheared, brecciated, and sericitized trondhjemite. The shear zones are up to ten feet or so wide. The veins contain chalcopyrite, pyrite, hematite, magnetite, azurite, and malachite. The mineralization extends beyond the vein margins into the trondhjemite. Of 63 rock samples collected from 1969-1975 by private interests, 8 had Cu values of more than 200 ppm, and 8 had Zn values of more than 200 ppm (Karl, 1992). One sample of a chalcopyrite-bearing quartz vein contained 6900 ppm Cu. Karl's (1992) samples of sulfide-bearing trondhjemite contained as much as 5500 ppm Cu; and a sample of a quartz-calcite-sulfide vein contained 0.08 ppm Au and 15,000 ppm Cu.
Comment (Geology): Age = The fissure veins probably are Late Cretaceous or younger in age.
References
Reference (Deposit): Berg, H.C., 1972, Geologic map of Annette Island, Alaska: U.S. Geological Survey Miscellaneous Geologic Investigations Map I-684, 8 p., 1 sheet, scale 1:63,360,
Reference (Deposit): Elliott, R.L., Berg, H.C., and Karl, Susan, 1978, map and table describing metalliferous and selected nonmetalliferous mineral deposits, Ketchikan and Prince Rupert quadrangles, Alaska: U.S. Geological Survey Open-file Report, 78-73-B,17 p., scale 1:250,000.
Reference (Deposit): Karl, S.M., 1992, Map and table of mineral deposits on Annette Island, Alaska: U.S. Geological Survey Open-File Report 92-690, 57 p., 1 map, scale 1:63,360.
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