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  3. Mineral Resource Data System (MRDS)

Unnamed (east of inner Sylburn Harbor)

Occurrence in Alaska, United States with commodity Copper
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Sections on this page
  1. Identification information
  2. Geographic coordinates
  3. Site location context
  4. Geographic areas
  5. Commodities
  6. Materials information
  7. Alteration
  8. Mineral occurrence model information
  9. Nearby scientific data
  10. Economic information about the deposit and operations
  11. Mining district
  12. Links to other databases
  13. Bibliographic references
  14. General comments
  15. Reporter information

Geologic information

Identification information

Deposit ID 10308880
MRDS ID A012379
Record type Site
Current site name Unnamed (east of inner Sylburn Harbor)
Related records 10112990, 10001615

Geographic coordinates

Geographic coordinates: -131.55276, 55.17674 (WGS84)
Relative position This site consists of three, roughly E-W aligned, occurrences at 200-300 feet elevation, and 0.3-0.7 mile east of the head of Sylburn Harbor. The occurrences are in section 21, T. 77 S., R. 92 E., of the Copper River Meridian. The coordinates are for the approximate center of the line of occurrences. The site corresponds to locs. 19 and 20 in Berg (1972 [I 684]), loc. no. 137 in Elliott and others (1978), and loc. 18a-c in Karl (1992). The location is accurate within 0.2 mile.

Site location context

Political divisions (FIPS codes)

Prince of Wales-Hyder(Census area)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Ketchikan A-5(quadrangle 1:63,360 scale)

Ketchikan SW(quadrangle 1:100,000 scale)

Ketchikan(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Ketchikan(hydrologic unit)

Southern Southeast Alaska(hydrologic accounting unit)

Southeast Alaska(hydrologic subregion)

Alaska(hydrologic region)

Federal lands

Annette Island Indian Reservation(American Indian Reservation)

American Indian Reservation BIA(Type of land area)

BIA(Federal land areas administered by BIA)

Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Copper Primary

Materials information

Materials Type of material
Azurite Ore
Chalcopyrite Ore
Hematite Ore
Magnetite Ore
Malachite Ore
Pyrite Ore
Calcite Gangue
Quartz Gangue

Alteration

  • 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.

Mineral occurrence model information

Model code 85
USGS model code 22c
Deposit model name Polymetallic veins
Mark3 model number 46

Nearby scientific data

(1) -131.55276, 55.17674
ListMap

Economic information

Comments on the geologic information

  • 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.
  • Age = The fissure veins probably are Late Cretaceous or younger in age.

Economic information about the deposit and operations

Development status Occurrence
Commodity type Metallic

Mining district

District name Ketchikan

Comments on the workings information

  • 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.

Reference information

Bibliographic references

Comments on the references

  • Primary Reference = Karl, 1992

General comments

Subject category Comment text
Deposit Model Name = Polymetallic veins (Cox and Singer, 1986; model 22c)

Reporter information

Type Date Name Affiliation Comment
Reporter 06-JUL-1999 H.C. Berg U.S. Geological Survey

Beyond USGS

Supplemental information added by qvyshift.com. Not part of the original USGS MRDS record.

Maps centered on this site

Authoritative Alaska resources

These are landing pages for further research — the state agencies don't currently expose per-mine deep links.