Foot Bay

Occurrence, Inactive

Commodities and mineralogy

Main commodities Cu
Other commodities Ag; Au; Mo
Ore minerals chalcopyrite; molybdenite; pyrite

Geographic location

Quadrangle map, 1:250,000-scale CG
Quadrangle map, 1:63,360-scale A-3
Latitude 56.048
Longitude -158.769
Nearby scientific data Find additional scientific data near this location
Location and accuracy This mineral occurrence is insec. 2, T. 48 S., R. 61 W., of the Seward Meridian, approximately 2 miles west of Foot Bay, near the head of a small northeast-flowing drainage. The location is accurate to within 1/2 mile.

Geologic setting

Geologic description

This site is marked by a color anomaly which occupies an area of approximately 1/2 by 1 mile along the northern contact zone of a small diorite stock (Fields, 1977). The stock intrudes siltstone, sandstone, grit, and conglomerate of the Cretaceous Hodoo Formation, which exhibits strong hornfelsing near the contact zone.
A peripheral pyrite-bearing fracture zone is present along the northern contact. The sulfide content in this zone is up to 5 percent, whereas the intrusive contains 1 percent or less sulfides (Fields, 1977).
Two rock samples collected by Bear Creek Mining Company in 1976 contained values of about 230 ppm copper and 2 ppm molybdenum along with traces of lead, zinc, and precious metals. One high-grade sample collected near the contact had metal values of 2300 ppm copper, 1.9 ppm gold, 2 ppm molybdenum, and 4.6 ppm silver.
Geologic map unit (-158.771011437185, 56.0472139081733)
Mineral deposit model Porphyry copper; porphyry copper-molybdenum (Cox and Singer, 1986; models 17, 21a).
Mineral deposit model number 17, 21a
Age of mineralization Tertiary.

Production and reserves

Workings or exploration This site was briefly examined and sampled by Bear Creek Mining Company in 1976 (Fields, 1977). Two of the rock samples contained about 230 ppm copper and 2 ppm molybdenum along with minor base and precious values. A high-grade sample collected near the contact had metal values of 2300 ppm copper, 1.9 ppm gold, 2 ppm molybdenum, and 4.6 ppm silver.
Indication of production None

Additional comments

This mineral occurrence is located within the Alaska Peninsula National Wildlife Refuge.

References

MRDS Number A012453
Reporters S.H. Pilcher (Anchorage)
Last report date 2/8/2000