Lake

Prospect in Alaska, United States with commodities Lead, Zinc

Geologic information

Identification information

Deposit ID 10001582
MRDS ID A012337
Record type Site
Current site name Lake
Related records 10209517

Geographic coordinates

Geographic coordinates: -131.19676, 55.40864 (WGS84)
Relative position The Lake prospect is at an elevation of about 200 feet on Fish Creek, about 0.1 mile above the junction of Silver Creek. The site is in section 31, T. 74 S., R. 94 E., of the Copper River Meridian. It corresponds to loc. 84 in Elliott and others (1978). The location is accurate within 0.1 mile. ? Also see Additional comments.
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Lead Primary
Zinc Primary

Materials information

Materials Type of material
Galena Ore
Pyrite Ore
Sphalerite Ore
Quartz Gangue

Mineral occurrence model information

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

Host and associated rocks

  • Host or associated Associated
    Rock type Plutonic Rock > Mafic Intrusive Rock > Diorite
    Stratigraphic age (youngest) Late Cretaceous
  • Host or associated Host
    Rock type Metamorphic Rock > Schist > Greenschist

Nearby scientific data

(1) -131.19676, 55.40864

Comments on the geologic information

  • Geologic Description = The country rocks in this part of Revillagigedo Island are marine, interbedded, andesitic and basaltic metavolcanic rocks and subordinate pelitic metasedimentary rocks that are intruded by stocks, sills, and dikes of Cretaceous feldspar-porphyritic granodiorite (Berg and others, 1988). The strata and some of the granodiorite were regionally metamorphosed to greenschist grade in Late Cretaceous time. These regionally metamorphosed rocks subsequently were locally remetamorphosed to hornblende hornfels near the contacts of Cretaceous granodiorite plutons that were emplaced after the regional metamorphism. The premetamorphic age of the strata is uncertain. Berg and others (1988) assign them a Mesozoic or (late) Paleozoic age. Berg (1982) and Crawford and others (in press) assign them to the Gravina belt, of Late Jurassic or Cretaceous age, or to the Taku terrane, of late Paleozoic to Late Triassic age. The metamorphic and intrusive rocks locally are overlain by basalt and andesite lava flows of Quaternary or Tertiary age.? the deposit consists of sulfide-bearing quartz fissure veins in intercalated metapelitic and metavolcanic (greenstone) schists near the contact of a granodiorite puton (Wright and Wright, 1908, p. 149). The sulfide minerals are pyrite, galena, and sphalerite, generally in small amounts. The largest vein reportedly is up to 60 feet wide; it strikes N15W and dips vertically, across the foliation of the schists.
  • Age = Late Cretaceous or younger.

Economic information

Economic information about the deposit and operations

Development status Prospect
Commodity type Metallic

Mining district

District name Ketchikan

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS A012337
USGS Alaska Resource Data File ARDF KC087

Bibliographic references

  • Deposit

    Wright, F.E., and Wright, C.W., 1908, The Ketchikan and Wrangell mining districts, Alaska: U.S. Geological Survey Bulletin 347, 210 p.

Comments on the references

  • Primary Reference = Wright and Wright, 1908

General comments

Subject category Comment text
Deposit Model Name = Polymetallic veins (Cox and Singer, 1986; model 22c)
Deposit Other Comments = Wright and Wright refer to this property as 'Lake claims nos. 1, 2, and 3.' ?The site is at the boundary of, or within, Misty Fiords National Monument Wilderness.

Reporter information

Type Date Name Affiliation Comment
Reporter 03-JUL-1999 H.C. Berg U.S. Geological Survey