Prospect in Alaska, United States with commodities Copper, Molybdenum, Lead, Tungsten

Geologic information

Identification information

Deposit ID 10308983
MRDS ID A010340
Record type Site
Current site name Lillie
Alternate or previous names Unnamed (south of Dry Pass)
Related records 10112583, 10234301, 10258400, 10161009, 10000294

Geographic coordinates

Geographic coordinates: -133.41586, 56.14973 (WGS84)
Relative position Prospects, occurrences, and claims in an area of several square miles on northern Kosciusko Island, south of Dry Pass. Coordinates are for the approximate center of activity. Locality 50 and 51 of Grybeck, Berg, and Karl (1984).
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Geographic areas

Country State
United States Alaska


Commodity Importance
Copper Primary
Molybdenum Primary
Lead Primary
Tungsten Primary

Comments on the commodity information

  • Gangue = Calcsilicate minerals

Materials information

Materials Type of material
Chalcopyrite Ore
Galena Ore
Magnetite Ore
Molybdenite Ore
Powellite Ore
Pyrite Ore
Pyrrhotite Ore
Scheelite Ore
Marble Gangue
Quartz Gangue


  • Contact metamorphic/metasomatic alteration with development of calcsilicate minerals in marble at periphery of the pluton at Dry Pass.

Mineral occurrence model information

Model code 42
USGS model code 14a
Deposit model name W skarn

Nearby scientific data

(1) -133.41586, 56.14973

Comments on the geologic information

  • Geologic Description = Several mineral deposits occur near the contact of a Cretaceous quartz monzonite pluton bordered by Cretaceous marble metamorphosed from Silurian Heceta Limestone (Brew, and others, 1984); all the deposits are probably related to this contact zone. At the Lillie prospect (Denny, 1961; Herreid and Kaufman, 1964) a band of tactite about 100 feet wide in diorite contains joint coatings and disseminated irregular masses, less than a half-inch in diameter, of molybdenite and subordinate powellite, chalcopyrite, pyrite, and magnetite. At another unnamed occurrence, a band of magnetite about 3 feet wide follows the contact between a diorite dike and marble. At another, samples of hornfels, marble, and diorite collected from a dump outside a short caved adit contain variable amounts of magnetite, molybdenite, chalcopyrite, pyrrhotite, pyrite, and galena. Quartz veins near the adit contain scheelite and a 5-foot chip sample of the vein contained 1.4% WO3. Quartz-rich rock near a marble-diorite contact also carry disseminated scheelite. These and additional showings of molybdenite, pyrite, and chalcopyrite in the contact zone of the pluton suggest the possibility of a porphyry copper or molybdenum deposit as well as more contact metamorphic deposits in the vicinity. Also see 'Workings/exploration'.
  • Age = Cretaceous based on probable genetic relationship to nearby pluton.

Economic information

Economic information about the deposit and operations

Development status Prospect
Commodity type Metallic

Comments on exploration

  • Status = Active?

Mining district

District name Ketchikan

Comments on the production information

  • Production Notes = None

Comments on the reserve resource information

  • Reserves = None

Comments on the workings information

  • Workings / Exploration = Old prospects and occurrences on which little recent work apparently has been done beyond minor surface exploration and a short adit (said to be 100 feet long). Twenty-seven lode claims were staked in the area in 1961 (U. S. Bureau of Mines, 1980) and an even bigger block is shown on the 1995 Alaska land status map. Extent and type of work done on these claims in recent years is unknown.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Alaska Resource Data File ARDF PE046
USGS Mineral Resources Data System MRDS A010340
USGS Mineral Resources Data System MRDS A010341

Bibliographic references

  • Deposit

    Denny, R.L., 1961, Lillie, Hawkins, and Eichner Moly prospect (Koscuisko Island): Alaska Territorial Department of Mines Prospect Evaluation 117-7, 3 p

  • Deposit

    Herreid, G.H., and Kaufman, M. A., 1964, Geology of the Dry Pass area, southeastern Alaska: Alaska Division of Mines and Minerals Geologic Report 7, 16 p.

  • Deposit

    Cobb, E.H., 1978, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Petersburg quadrangle, Alaska: U.S. Geological Survey Open-File Report 78-870, 53 p.

  • Deposit

    Cobb, E.H., 1972, Metallic mineral resources map of the Petersburg quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-415, 1 sheet, scale 1:250,000.

  • Deposit

    U.S. Bureau of Mines, 1980, Claim map, Petersburg quadrangle, Alaska: U.S. Bureau of Mines Map 117, 1 sheet, scale 1:250,000.

  • Deposit

    Brew, D. A., Ovenshine, A. T., Karl, S. M., and Hunt, S. J., 1984, Preliminary reconnaissance geologic map of the Petersburg and parts of the Port Alexander and Sumdum 1:250,000 quadrangles, southeastern Alaska: U.S. Geological Survey Open-File Report 84-405, 43 p., 2 sheets, scale 1:250,000.

  • Deposit

    Grybeck, D.J., Berg, H.C., and Karl, S.M., 1984, Map and description of the mineral deposits in the Petersburg and eastern Port Alexander quadrangles: U.S. Geological Survey Open-File Report 84-837, 86 p., 1 sheet, scale 1:250,000.

  • Deposit

    Herreid, G.H., and Kaufman, M. A., 1964, Geology of the Dry Pass area, southeastern Alaska: Alaska Division of Mines and Minerals Geologic Report 7, 12 p.

Comments on the references

  • Primary Reference = Herreid and Kaufman, 1964

General comments

Subject category Comment text
Deposit Model Name = Various types of skarn deposits (Cox and Singer, 1986; models 14a, 18a, 18b, 18c, and 18d).
Deposit Model Number = 14a, 18a, 18b, 18c, and 18d

Reporter information

Type Date Name Affiliation Comment
Reporter 01-NOV-1998 H.C. Berg and D.J. Grybeck U.S. Geological Survey