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  3. Mineral Resource Data System (MRDS)

Unnamed (east of Swan Lake)

Occurrence in Alaska, United States with commodity Molybdenum
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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 10001568
MRDS ID A012317
Record type Site
Current site name Unnamed (east of Swan Lake)

Geographic coordinates

Geographic coordinates: -131.22871, 55.60864 (WGS84)
Relative position This occurrence is about 2.0 miles east of Swan Lake, on the crest of a north-northeast-trending ridge at an elevation of 3650 feet. The site is on the boundary between sections 19 and 20, T. 72 S., R. 92 E., of the Copper River Meridian. It corresponds to loc. 50.1 in Elliott and others (1978). The location is accurate within 0.1 mile.

Site location context

Political divisions (FIPS codes)

Ketchikan Gateway(Borough)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Ketchikan C-4(quadrangle 1:63,360 scale)

Ketchikan NW(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

Tongass National Forest(National Forest)

National Forest FS(Type of land area)

FS(Federal land areas administered by FS)

Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Molybdenum Primary

Materials information

Materials Type of material
Molybdenite Ore

Alteration

  • (Local) Locally conspicuous iron-staining.

Mineral occurrence model information

Model code 80
USGS model code 21b
Deposit model name Porphyry Mo, low-F

Nearby scientific data

(1) -131.22871, 55.60864
ListMap

Economic information

Comments on the geologic information

  • Geologic Description = The country rocks near this prospect are pelitic schist and gneiss, and subordinate andesitic and basaltic metavolcanic rocks, that are intruded by Cretaceous stocks, sills, and dikes of feldspar-porphyritic granodiorite, and by small metadiorite plutons of undetermined age (Berg and others, 1988). The strata were regionally metamorphosed to upper greenschist or amphibolite grade in Cretaceous time, and, near some of the granodiorite contacts, subsequently contact metamorphosed to hornblende hornfels. The premetamorphic age range of the strata is unknown. Berg and others (1988, p. 17) assigned them an undivided Mesozoic or Paleozoic age. More recent studies suggest that at least some of the strata may be as old as Precambrian (Crawford and others, in press).? This occurrence consists of sparsely disseminated, minute particles of molybdenite in a rusty-weathering, 45-foot-thick granodiorite(?) sill that intrudes pelitic paragneiss (Elliott and others, 1978). An analysis of the molybdenite-bearing rock showed 150 ppm Mo (Koch and Elliott, 1978 [OFR 78-156A]). The molybdenite may be a late-stage hydrothermal mineral in the granodiorite.
  • Age = Cretaceous

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 = An analysis of the molybdenite-bearing rock showed 150 ppm Mo (Koch and Elliott, 1978 [OFR 78-156A]).

Reference information

Comments on the references

  • Primary Reference = Elliott and others, 1978

General comments

Subject category Comment text
Deposit Model Name = Porphyry Mo, low-F? (Cox and Singer, 1986; model 21b)
Deposit Other Comments = Site is on the western boundary of Misty Fiords National Monument Wilderness.

Reporter information

Type Date Name Affiliation Comment
Reporter 01-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.