Syenite Gulch

Occurrence, Inactive

Commodities and mineralogy

Main commodities Th; U
Ore minerals thorite; uranothorianite

Geographic location

Quadrangle map, 1:250,000-scale CA
Quadrangle map, 1:63,360-scale B-5
Latitude 65.48
Longitude -161.23
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is at an elevation of about 1,600 feet, approximately 2.5 miles north of Granite Mountain. The site is in section 19, T. 1 N., R. 12 W., of the Kateel River Meridian. Cobb, 1972 (MF-389), location 33.

Geologic setting

Geologic description

At this occurrence, uranothorite and thorite(?) occur in stream sediments overlying monzonite or syenite of the Late Cretaceous Granite Mountain pluton (Gault and others, 1953). Samples from prospect pits indicate that the amount of radioactivity decreases with depth. The highest equivalent uranium value from the samples was 0.088 percent.
Geologic map unit (-161.2326410412, 65.4793290717533)
Mineral deposit model Radioactive minerals in stream sediments.
Age of mineralization Late Cretaceous.

Production and reserves

Workings or exploration In 1947, the U.S. Geological Survey sampled the creek to evaluate the radioactive mineral potential.
Indication of production None

Additional comments

Stream gradient over 200 feet per mile.