Unnamed (southeast of mouth of Stag Bay)

Prospect, Probably inactive

Commodities and mineralogy

Main commodities Cu; Fe
Ore minerals chalcopyrite; magnetite

Geographic location

Quadrangle map, 1:250,000-scale SI
Quadrangle map, 1:63,360-scale D-8
Latitude 57.9091
Longitude -136.3403
Nearby scientific data Find additional scientific data near this location
Location and accuracy This prospect is on the northeast flank of Mount Hill, about 1.3 miles southeast of the mouth of Stag Bay. The prospect is at an elevation of about 500 feet, 0.4 mile east-southeast of the center of sec. 4, T. 46 S., R. 56 E. It is location P-37 of Bittenbender and others (1999), MAS no. 0021140088 (U.S. Bureau of Land Management, 2002), and is included in location 7 of Cobb (1972, 1978). The location is accurate within about 0.2 mile.

Geologic setting

Geologic description

Johnson and Karl map two geologic units in the area of this prospect. One is the Freeburn assemblage, a collage of kilometer-scale, fault-bounded, lozenge-shaped blocks of Cretaceous and Cretaceous(?) metasedimentary and metavolcanic rocks. The other is Mesozoic or Paleozoic amphibolite, gneiss, schist, and marble. The contact between the units is the Border Ranges Fault, a northwest-striking, steeply-dipping or vertical regional fault that separates Cretaceous or younger rocks on the southwest from Mesozoic or Paleozoic rocks on the northeast. The prospect is on or near this fault.
Bittenbender and others (1999), citing work by Asbury (1964) and Kimball (1982), describe the deposit as an iron-copper skarn in a fault near a diorite-gabbro contact with marble. Samples of the mineralized rock contained up to 51 percent iron, 0.93 percent titanium dioxide, and 100 parts per million copper. Workings included 3 trenches, one of which is caved.
Geologic map unit (-136.34213791521, 57.9087185491462)
Mineral deposit model Fe skarn (Cox and Singer, 1986; model 18d).
Mineral deposit model number 18d
Alteration of deposit Unspecified skarn minerals.

Production and reserves

Workings or exploration Workings included three trenches, one of which is caved.
Indication of production None

Additional comments

The prospect is in West Chichagof-Yakobi Wilderness.


MRDS Number AO13243


Reporters H.C. Berg (U.S. Geological Survey)
Last report date 10/16/2004