Unnamed (south of Selawik Lake)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Th; U
Ore minerals zircon

Geographic location

Quadrangle map, 1:250,000-scale SE
Quadrangle map, 1:63,360-scale B-3
Latitude 66.34
Longitude -160.38
Nearby scientific data Find additional scientific data near this location
Location and accuracy The occurrence is at an elevation of about 1,300 feet on hill 1378, about 3 miles south of the southeast end of Selawik Lake. The site is in section 21, T. 11 N., R. 8 W., of the Kanteel River Meridian. Barker (1985), anomalous area 2, location O.

Geologic setting

Geologic description

The country rocks in the area of this occurrence consist of the mid-Cretaceous Selawik lake and Inland Lake alkaline intrusive complexes. There are three types of radioactive occurrences in the Selawik Lake complex: quartz veins associated with a fault zone; lamprophyre dikes; and radioactive zones in nepheline syenite. According to Barker (1985), at location O, boulders of medium-grained syenite displayed up to 4 times the background radioactivity. Chip sample 4R contained 123 ppm U3O8 and 380 ppm Th. Pronounced metamict halos surrounding zircon grains in biotite suggest that at least some of the radioactive material is in the zircon. A fine-grained syenite intermixed with rubble at this location contained 36 ppm U3O8 and 91 ppm Th.
Geologic map unit (-160.382726622964, 66.3393596205638)
Mineral deposit model Radioactive occurrences in syenite and nepheline syenite.
Age of mineralization Cretaceous.

Production and reserves

Workings or exploration The area was visited by U.S. Geological Survey geologists and the U.S. Bureau of Mines. Several rock and stream sediment samples were collected from the area.
Indication of production None

References