Bloom

Prospect, Inactive

Commodities and mineralogy

Main commodities Fe
Ore minerals pyrite

Geographic location

Quadrangle map, 1:250,000-scale MM
Quadrangle map, 1:63,360-scale C-1
Latitude 63.6924
Longitude -150.4596
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Bloom prospect is on a north-facing cliff on the south bank of Canyon Creek, about 500 feet below the mouth of the North Fork. The location is accurate within 500 feet. The prospect is occurrence 103 of Thornsberry, McKee, and Salisbury (1984).

Geologic setting

Geologic description

The country rocks at the Bloom prospect are interlayered, thinly- laminated and locally graphitic black quartzite and thinly-laminated tan quartzite. The rocks are sheared subparallel to their foliation (Thornsberry, McKee, and Salisbury, 1983, occurrence 103). The graphitic units are thickly coated with yellow to white sulfate(?), a common indicator of pyrite in unweathered rock. In 1983, the U.S. Bureau of Mines collected several samples at the site, but assays showed no significant concentrations of valuable metals. Gold and silver were not determined. Antimony values ranged from 6 to 30 ppm (Thornsberry, McKee, and Salisbury, 1984, v. 2).
Geologic map unit (-150.461893327138, 63.6919073833341)
Mineral deposit model Possible stratabound sulfide occurrences in graphitic layers of Birch Creek Schist.
Age of mineralization Holocene weathering of Precambrian country rocks.
Alteration of deposit Extensive surface development of secondary sulfates.

Production and reserves

Workings or exploration Workings consist of a 3- by 3- foot pit (adit-cut).
Indication of production None

Additional comments

The prospect is in Denali National Park and Preserve.

References