Unnamed (head of Hartman River)

Occurrence in Alaska, United States with commodities Gold, Molybdenum, Tungsten, Silver, Copper, Antimony

Geologic information

Identification information

Deposit ID 10002163
MRDS ID A013060
Record type Site
Current site name Unnamed (head of Hartman River)

Geographic coordinates

Geographic coordinates: -153.68611, 61.72475 (WGS84)
Relative position This occurrence is on a ridge along the north side of the upper Hartman River valley. It is at an elevation of 6,000 feet, one mile north of the glacier in the northwest headwater tributary of Hartman River. The map site is in the NE1/4 section 19, T 19 N, R 24 W, of the Seward Meridian. This is locality 3 of Cobb (1972 [MF 412]; 1976 [OF 76-485]) and and Cobb and Reed (1981). The location is probably accurate to within a quarter of a mile.
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Gold Primary
Molybdenum Primary
Tungsten Primary
Silver Secondary
Copper Secondary
Antimony Secondary

Materials information

Materials Type of material
Chalcopyrite Ore
Molybdenite Ore
Pyrite Ore
Calcite Gangue
Limonite Gangue
Quartz Gangue

Alteration

  • (Local) Silicification and oxidation.

Mineral occurrence model information

Model code 81
USGS model code 21c
Deposit model name Porphyry W

Host and associated rocks

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

Nearby scientific data

(1) -153.68611, 61.72475

Comments on the geologic information

  • Geologic Description = Reed and Elliott (1970, p. 22) reported that a 2-inch-wide quartz vein containing less than 2 percent finely disseminated molybdenite crosscuts quartz diorite at this locality. A sample of this vein also contained 300 ppm tungstenand 3.2 ppm gold. Allen and others (1990, samples 104, 111, 112) collected several samples from the south flank of the ridge where this vein was found. These samples were of graywacke containing disseminated pyrite; limonite-stained quartz veins containing pyrite and some chalcopyrite; and quartz-calcite veins in granitic rock. These samples contained as much as 3.5 ppm gold, 200 ppm silver, 700 ppm copper, 150 ppm antimony, and greater than 10,000 ppm arsenic. The sedimentary rocks are Jurassic and Lower Cretaceous, and the Upper Cretaceous or Tertiary granitic rocks are part of the Alaska-Aleutian Range batholith (Reed and Lanphere, 1973; Nokleberg and others, 1994).
  • Age = Late Cretaceous or Tertiary. The veins crosscut granitic rocks of the Upper Cretaceous or Tertiary part of the Alaska-Aleutian Range batholith.

Economic information

Economic information about the deposit and operations

Development status Occurrence
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name McGrath

Comments on the workings information

  • Workings / Exploration = Reconnaissance surface observation and sampling has been completed at this locality (Reed and Elliott, 1970).

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS A013060
USGS Alaska Resource Data File ARDF LH011

Bibliographic references

  • Deposit

    Reed, B. L., and Lanphere, M. A., 1973, Alaska-Aleutian Range batholith-- Geochronology, chemistry, and relation to circum-Pacific plutonism: Geological Society of America Bulletin, v. 84, no. 8, p. 2583-2610.

  • Deposit

    Allen, M. S., Malcolm, M. J., Motooka, J. M., and Slaughter, K. E., 1990, Geologic description, chemical analyses, and sample locality map for rock samples collected from the eastern part of the Lime Hills quadrangle, Alaska: U.S. Geological Survey Open-File Report 90-69, 49 p.?

  • Deposit

    Nokleberg, W.J., and others, 1994, Metallogeny and major mineral deposits of Alaska and Metallogenic map of significant metalliferous lode deposits and placer districts of Alaska, in Plafker, G. and Berg, H.C., eds., The Geology of Alaska: Boulder, Colorado, Geological Society of America: The Geology of North America, v. G1, p. 855-904 and v. G1, Plate 11, scale 1:2,500,000.

  • Deposit

    Cobb, E.H., 1976, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Iliamna, Lake Clark, Lime Hills, and McGrath quadrangles, Alaska: U.S. Geological Survey Open-File Report 76-485, 101 p.

  • Deposit

    Cobb, E.H., and Reed, B.L., 1981, Summaries of data on and lists of references to metallic and selected nonmetallic mineral occurrences in the Iliamna, Lake Clark, Lime Hills, and McGrath quadrangles, Alaska; Supplement to Open-File Report 76-485; Part A, Summaries to January 1, 1981: U.S. Geological Survey Open-File Report 81-1343-A, 25 p.

  • Deposit

    Reed, B.L., and Elliott, R.L., 1970, Reconnaissance geologic map, analyses of bedrock and stream sediment samples, and an aeromagnetic map of parts of the southern Alaska Range: U.S. Geological Survey Open-File Report 70-217, 145 p., 1 sheet, scale 1:250,000. (Also published as U.S. Geological Survey Open-File Report 413).

  • Deposit

    Cobb, E.H., 1972, Metallic mineral resources map of the Lime Hills quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-412, 1 sheet, scale 1:250,000.

Comments on the references

  • Primary Reference = Reed and Elliott, 1970

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 10-JUN-2001 Travis L. Hudson Applied Geology
Reporter 10-JUN-2001 Travis L. Hudson Applied Geology