Progress report on uranium investigations in the Zane Hills area, west-central Alaska

The Zane Hills pluton underlies a mountainous area of about 460 km² in west-central Alaska and is locally enriched in uranium and thorium (Miller and Ferrians, 1968; Miller, 1970; Staatz and Miller, 1976). While over 90 percent of the pluton consists of granodiorite with average contents of uranium and thorium, zones of porphyritic to gneissic monzonite along the southern and eastern margins of the pluton (fig. 1) contain as much as 100 ppm (parts per million) uranium and 269 ppm thorium (Staatz and Miller, 1976; table 1, this report). This report presents information obtained in 1976 on the relationship of the uraniferous monzonite to the granodiorite and on uranium enrichment outside the pluton as part of an on-going study of the area.