Unnamed (in headwaters of Penny Creek)

Prospect, Inactive

Commodities and mineralogy

Main commodities Au; Cu
Ore minerals malachite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale SO
Quadrangle map, 1:63,360-scale C-5
Latitude 64.677
Longitude -164.386
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is on the low ridge, at about 650 feet elevation, between the headwaters of Penny Creek (SO018) and Minnesota Creek. It is locality 11 of Asher (1969, DGGS R33).

Geologic setting

Geologic description

This occurrence is one of several in the area where sparse disseminated copper minerals, mainly malachite, occur in silica-rich rocks along the contact between marble and schist. Grab samples of these rocks contain 0.13 to 0.78 percent Cu but generally only traces of gold. However, samples from this specific locality contained 0.02 to 0.08 ounces Au per ton and 0.02 to 0.04 ounces Ag per ton (Asher, 1969, DGGS R33). This type of copper occurrence is present at several localities in the western Solomon quadrangle (Gamble, 1988) and has similarities to several in the Kougarok area of the northeastern Teller quadrangle. In the Teller quadrangle, the Ward mine (TE071) is an example of this type of copper mineral occurrence. The Ward mine has been described as a zone of silicification in marble above a thrust contact with underlying metapelitic schist (Sainsbury and others, 1969; Sainsbury, 1975, p. 90-94). The silica-rich rocks have been metamorphosed and commonly have a laminar fabric. Copper-bearing minerals, mostly malachite but also including azurite and in places chalcopyrite and possibly bornite, are disseminated in the silica-rich rocks. The minor sulfides tend to be along faint laminae and joints (Sainsbury and others, 1969, p. 22). Malachite and azurite also occur in small veins and veinlets in the silica-rich rocks. The summary characterization of this type of Seward Peninsula mineral deposit by Sainsbury (1975, p. 90-94) contains inconsistencies with some descriptions of these deposits. Their origin is uncertain and other possibilities should be considered. One possiblity is that the silica-rich rocks are quartzites and that there is a stratigraphic control to the Ward deposit and similar occurrences elsewhere on Seward Peininsula. Quartzite at the base of the regional carbonate assemblage is recognized elsewhere in the Kougarok Mountain area (Puchner, 1986, p. 1777). Bedrock in the area of this occurrence is part of a lower Paleozoic metasedimentary assemblage (Till and others, 1986).
Geologic map unit (-164.38860726557, 64.6762557364545)
Mineral deposit model Copper-bearing mineralization in silica-rich zones at or near base of marble.
Age of mineralization Unknown; if stratigraphic controls are important then it is probably Paleozoic in age.
Alteration of deposit Silicification (?) and oxidation; the development of silica-rich rocks at or near the the base of Paleozoic marble overlying characterizes this type of copper occurrence.

Production and reserves

Workings or exploration No exploration or development work is reported for this occurrence.
Indication of production None

References

MRDS Number A012605

References

Reporters Travis L. Hudson (Applied Geology)
Last report date 8/19/1999