thumbnail

Reconnaissance for radioactive deposits in the Nixon Fork mining district, Medfra Quadrangle, central Alaska, 1949

Trace Elements Investigations 75

This report concerns work done on behalf of the Division of Raw Materials of the U.S. Atomic Energy Commission
By:
and

Links

Abstract

Reconnaissance for radioactive deposits in the Nixon Fork mining district, Medfra quadrangle, central Alaska, in 1949 disclosed the occurrence of allanite in sampled containing as much as 0.05 percent equivalent uranium from the dump of the Whalen mine; the presence of radioactive parisite (a rare-earth fluocarbonate) in a highly altered limestone containing about 0.025 percent equivalent uranium near the Whalen shaft; and radioactive idocrase in samples of altered garnet rock with about 0.025 percent equivalent uranium, form the Crystal shaft of the Nixon Fork mine. This radioactivity is due mostly to thorium rather than uranium. Placer concentrates from Ruby and Eagle Creeks contain 0.078 and 0.26 percent equivalent uranium respectively, in which the radioactivity is due chiefly to uraniferous thorianite. The bedrock source of the uraniferous thorianite was not located primarily because much of the area is overlain by a relatively thick mantle of vegetation (mostly moss) which limited the effectiveness of radiometric surveying. The uraniferous thorianite is believed to occur in a restricted zone or zones at or near the contact of limestone with monzonite similar to the gold-copper ores of the district and the deposits of radioactive parisite and garnet rock at the Whelan and Crystal shafts respectively.

Geospatial Extents

Additional Publication Details

Publication type:
Report
Publication Subtype:
USGS Numbered Series
Title:
Reconnaissance for radioactive deposits in the Nixon Fork mining district, Medfra Quadrangle, central Alaska, 1949
Series title:
Trace Elements Investigations
Series number:
75
Year Published:
1953
Language:
English
Publisher:
U.S. Geological Survey
Description:
Report: 27 p.; 1 Plate: 9.66 x 10.82 inches
Time Range Start:
1949-01-01
Time Range End:
1949-12-31
Country:
United States
State:
Alaska
Other Geospatial:
Nixon Fork Mining District