Omilak East

Prospect, Active

Commodities and mineralogy

Main commodities Ag; Cu; Pb; Zn
Ore minerals galena
Gangue minerals hematite

Geographic location

Quadrangle map, 1:250,000-scale BN
Quadrangle map, 1:63,360-scale A-2
Latitude 65.05
Longitude -162.56
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Omilak East prospect is located in the headwaters of the South Fork of Mosquito Creek, at an approximate elevation of 1,350 feet. Mosquito Creek flows westward from headwaters in the northern Darby Mountains to Telephone Creek, a tributary to Fish River in McCarthy's Marsh. It is locality 56 of Gamble (1988).

Geologic setting

Geologic description

Galena-bearing gossans and oxidized veins in schist are present here (Gamble, 1988). This is probably similar to the Foster prospect (BN098) although it is apparently not hosted by carbonate rocks. Gossan and veinlets are hosted by a calc-silicate schist and biotite schist unit (Hedderly-Smith, 1980). Geologic mapping, soil sampling, selected rock sampling, and EM surveys have been completed here by Greatland Exploration Ltd. (Hedderly-Smith, 1980). This work was primarily between 1976 and 1980. The reconnaissance soil sample lines have anomalous zinc values over a length of of at least 1,200 feet. Rock samples contain up to 4.4 % Pb, 3.4 % Zn, 0.2 % Cu, and 50 ounces/ton Ag. The EM survey defines a strong and continuous electrically conductive zone that is 11,000 feet long with a depth to top varying from 100 to 300 feet (Clayton, 1998). Surface mineralization is highly oxidized; galena and pyrite form remnant nodules in gossan. The indicated electrical conductivity is moderately high and permafrost, which may be present to a depth of a few hundred feet, may have reduced its intensity.
Geologic map unit (-162.562615270577, 65.0492947773674)
Mineral deposit model Polymetallic vein or replacement (Cox and Singer, 1986; model 19a? or 22c?).
Mineral deposit model number 19a? or 22c?
Age of mineralization Cretaceous ?; Epigenetic mineralization in metamorphic rocks of Seward Peninsula is primarily of Cretaceous age.
Alteration of deposit Oxidation; iron oxide-rich gossan float and fragments common in mineralized areas.

Production and reserves

Workings or exploration Geologic mapping, soil sampling, selected rock sampling, and EM surveys have been completed here by by Greatland Exploration Ltd. (Hedderly-Smith, 1980). This work was primarily between 1976 and 1980. The active claim group here is maintained by Greatland Exploration Ltd. (3512 Campbell Airstrip Road, Anchorage, AK 99504).
Indication of production None

References

MRDS Number 10307299

References

Clayton, R.H., 1998, The Omilak East Property of Greatland Exploration Ltd; Summary and Update: Anchorage, Alaska, Greatland Exploration Ltd. internal report, 7 p.
Hedderly-Smith, D.A, 1980, Summary report on the Omilak East property, Seward Peninsula, Alaska: Anchorage, Greatland Exploration Ltd., internal report, 48 p.
Reporters Travis L. Hudson (Applied Geology)
Last report date 3/15/1999