Unnamed (near Heart Mtn)

Occurrence in Alaska, United States with commodities Copper, Nickel

Geologic information

Identification information

Deposit ID 10308452
Record type Site
Current site name Unnamed (near Heart Mtn)

Geographic coordinates

Geographic coordinates: -152.08085, 62.88853 (WGS84)
Relative position Reed and others (1978, locality 11) show this site in a drainage one and a half miles east of Heart Mtn at about 4500 feet in elevation in the southwest quarter of Section 3, T. 32 N., R. 15 W., of the Seward Meridian within Denali National Park and Preserve.
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Copper Primary
Nickel Primary

Materials information

Materials Type of material
Chalcopyrite Ore
Pentlandite Ore
Pyrite Ore

Mineral occurrence model information

Model code 13
USGS model code 7a
Deposit model name Synorogenic-synvolcanic Ni-Cu
Mark3 model number 19

Nearby scientific data

(1) -152.08085, 62.88853

Comments on the geologic information

  • Geologic Description = Reed and others (1978) describe float samples of serpentinite, collected about a mile and a half east of Heart Mtn, that contain veins and irregular segregations of pyrite, chalcopyrite, and pentlandite(?). They indicate the source of the float is ultramafic rock to the south of this site, mapped as MzPzu by Reed and Nelson (1980). Chrome and nickel contents of the serpentinite (specific site not given) average 2000 ppm each (Reed and Nelson, 1980). Curtin, Karlson, O'Leary, Day and McDougal (1978) show a cluster of heavy-mineral concentrate samples with high copper (more than 7,000 ppm) and lead (more than 12,500 ppm) values in T. 32 N., and T. 33 N., R. 14 W. and R. 15 W., SM, an area ranging from one half to two miles east of Heart Mtn. They suggest the source of the high copper values in heavy-mineral concentrate samples is most likely a small body of serpentinite mapped as MzPzu by Reed and Nelson (1980) in T. 32 N., R. 15 W., SM. The source of the anomalous lead is not known. Chalcopyrite, malachite, arsenopyrite, and fluorite were observed under the microscope in several of the heavy-mineral concentrate samples with high copper values (Curtin, Karlson, O'Leary, Day and McDougal, 1978).
  • Age = Mesozoic and (or) Paleozoic (Reed and Nelson, 1980).

Economic information

Economic information about the deposit and operations

Development status Occurrence

Mining district

District name McGrath

Comments on the workings information

  • Workings / Exploration = Reconnaissance mapping, stream silt and rock sampling by the U.S. Geological Survey (Curtin, Karlson, O'Leary, Day and McDougal,1978; Reed and others,1978; Reed and Nelson, 1980) are all that have been described here. Chrome and nickel contents of the serpentinite (specific site not given) average 2000 ppm each (Reed and Nelson, 1980). Curtin, Karlson, O'Leary, Day and McDougal (1978) show a cluster of heavy-mineral concentrate samples with high copper (more than 7,000 ppm) and lead (more than 12,500 ppm) values in an area ranging from one half to two miles east of Heart Mountain.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Alaska Resource Data File ARDF TL076

Bibliographic references

  • Deposit

    Curtin, G.C., Karlson, R.C., O'Leary, R.M., Day, G.W., and McDanal, S.K., 1978, Geochemical and generalized geologic maps showing the distribution and abundance of gold and silver in the Talkeetna quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-870-E, 2 sheets, scale 1:250,000.

  • Deposit

    Reed, B.L., Nelson, S.W., Curtin, G.C., and Singer, D.A., 1978, Mineral resources map of the Talkeetna Quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-870-D, 1 sheet, scale 1:250,000.

  • Deposit

    Reed, B.L., and Nelson, S.W., 1980, Geologic map of the Talkeetna quadrangle: U.S. Geological Survey Miscellaneous Investigations Map I-1174, scale 1:250,000.

Comments on the references

  • Primary Reference = Reed and others, 1978

General comments

Subject category Comment text
Deposit Model Name = Possibly synorogenic-synvolcanic Ni-Cu (Cox and Singer, 1986; model 7a).
Deposit Other Comments = This site is within Denali National Park and Preserve.

Reporter information

Type Date Name Affiliation Comment
Reporter 10-AUG-98 Madelyn A. Millholland Millholland & Associates