Unnamed (north of confluence of Chickamin River and South Fork)

Occurrence in Alaska, United States with commodities Copper, Molybdenum, Silver, Lead, Zinc
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. Host and associated rocks
  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 10001549
MRDS ID A012296
Record type Site
Current site name Unnamed (north of confluence of Chickamin River and South Fork)

Geographic coordinates

Geographic coordinates: -130.70676, 55.88865 (WGS84)
Relative position This occurrence is at an elevation of about 600 feet in cliffs east of the Chickamin River, about 2 miles north of the mouth of the South Fork. The site is in section 16, T. 69 S., R. 96 E., of the Copper River Meridian. It corresponds to area M-4 in Berg and others (1977), and to loc. 19 in Elliott and others (1978). The location is accurate within 0.1 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 D-3(quadrangle 1:63,360 scale)

Ketchikan NW(quadrangle 1:100,000 scale)

Ketchikan(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Southern Southeast Alaska(hydrologic accounting unit)

Southeast Alaska(hydrologic subregion)

Alaska(hydrologic region)

Federal lands

Misty Fiords National Monument Wilderness(Wilderness)

Wilderness FS(Type of land area)

FS(Federal land areas administered by FS)

Tongass National Forest(National Forest)

National Forest FS(Type of land area)

FS(Federal land areas administered by FS)

Misty Fjords National Monument Wilderness(Wilderness)

Wilderness FS(Type of land area)

FS(Federal land areas administered by FS)

Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Copper Primary
Molybdenum Primary
Silver Secondary
Lead Secondary
Zinc Critical Secondary

Materials information

Materials Type of material
Chalcopyrite Ore
Pyrite Ore

Alteration

  • (Local) Conspicuous iron-staining.

Host and associated rocks

  • Host or associated Host
    Rock type Metamorphic Rock > Gneiss

Nearby scientific data

(1) -130.70676, 55.88865

Economic information

Comments on the geologic information

  • Geologic Description = The country rocks in the area of this occurrence consist chiefly of rusty-weathering pelitic paragneiss that forms roof pendants, screens, and inclusions in Tertiary or Cretaceous foliated granodiorite and quartz diorite of the Coast Range batholith (Berg and others, 1977, p. 126; Berg and others, 1988). The paragneiss probably represents marine argillaceous and clastic strata that underwent high-grade regional metamorphism in Cretaceous or Tertiary time. The premetamorphic age of the strata is uncertain, but they probably are mainly Paleozoic and may be as old as Precambrian (Berg and others, 1988, p. 26; Gehrels and others, 1990; Crawford and others, in press).? the occurrence consists of a zone of rusty-weathering pyritic paragneiss and schist, whose foliation strikes N30W and dips 55NE. The zone is about 450 feet thick and its outcrop can be traced along strike to the southeast for about 3 miles (Berg and others, 1977, p. 126 and pl. 2). The zone probably is the southeast extension of a similar rusty zone on the other side of Chickamin River (KC018). In addition to locally abundant pyrite, the rocks contain sparse chalcopyrite. Chip samples taken perpendicular to the foliation across about 350 feet of the zone assayed up to 150 ppm Mo, 95 ppm Cu, 15 ppm Pb, 80 ppm Zn, and 1 ppm Ag. One sample contained a trace (less than 0.05 ppm) of gold (Berg and others, 1977, p. 126 and fig. 36).

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 = Thirteen chip samples taken perpendicular to the foliation across about 350 feet of a 600-foot-thick zone of iron-stained paragneiss assayed up to 150 ppm Mo, 95 ppm Cu, 15 ppm Pb, 80 ppm Zn, and 1 ppm Ag. One sample contained a trace (less than 0.05 ppm) of gold (Berg and others, 1977, p. 126 and fig. 36).

Reference information

Comments on the references

  • Primary Reference = Berg and others, 1977

General comments

Subject category Comment text
Deposit Model Name = Disseminated base-metal sulfides in rusty-weathering paragneiss
Deposit Other Comments = Site is in Misty Fiords National Monument Wilderness.

Reporter information

Type Date Name Affiliation Comment
Reporter 29-JUN-1999 H.C. Berg U.S. Geological Survey

Beyond USGS

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

Authoritative Alaska resources

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