Uranium 4 (in Selawik Hills)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Th; U
Ore minerals xenotime

Geographic location

Quadrangle map, 1:250,000-scale SE
Quadrangle map, 1:63,360-scale A-3
Latitude 66.158
Longitude -160.214
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is at an elevation of about 1,900 feet in the NW1/4 section 29, T. 9 N., R. 7 W., of the Kateel River Meridian. Barker (1985), location I, sample 59R.

Geologic setting

Geologic description

The country rock in the area of this occurrence is the mid-Cretaceous Selawik Hills alkaline intrusive complex. The occurrence is one of several areas of anomalous radioactivity within the complex. According to Barker (1985), at location I, quartz veinlets associated with lineaments tentatively identified as shear zones cut foliated syenite and monzonite. The syenite and monzonite have been partially replaced by silica and chlorite. The margins of the presumed shear zones are more intensely altered and are host to quartz veinlets up to 0.5 inch thick. Accessory xenotime was observed in a thin section of this rock. Secondary biotite is locally present. Grab sample 59R, from the biotite alteration, contained 220 ppm U3O8 and 36 ppm Th. Radiometric readings over the presumed shear zones were 1.5 to 2 times background.
Geologic map unit (-160.216709926393, 66.1573587617979)
Mineral deposit model Radioactive shear zone in alkaline igneous complex.
Age of mineralization Cretaceous.
Alteration of deposit Biotization.

Production and reserves

Workings or exploration A grab sample from this site was analyzed by the U.S. Bureau of Mines (Barker, 1985).
Indication of production None