Preliminary summary review of thorium-bearing mineral occurrences in Alaska

Trace Elements Memorandum 339
This reports concerns work done on behalf of the Division of Raw Materials of the U.S. Atomic Energy Commission
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Thorium-bearing minerals are known at 47 localities in Alaska. At these localities the thorium occurs as a major constituent or in minor amounts as an impurity in one or more of the following 12 minerals: allanite, columbite, ellsworthite, eschynite, gummite, monazite, orangite, parisite, thorianite, thorite, xenotime, and zircon. In addition other minerals, such as biotite and sphene, are radioactive and may contain thorium. Several unidentified columbate minerals with uranium or thorium and uranium as major constituents have been recognized at some localities. The distribution, by type of deposit, of the 57 thorium occurrences is as follows: lode - 3, lode and placer - 1, granitic rock - 3, granitic rock and related placer - 14, and placer - 26. Of the four lode occurrences only the radioactive veins at Salmon Bay in southeastern Alaska and the contact metamorphic deposit in the Nixon Fork area of central Alaska warrant further consideration, although insufficient data are available to determine whether these two deposits have commercial possibilities. The remaining occurrences of thorium-bearing minerals in Alaska are limited to placer deposits and disseminations of accessory minerals in granitic rocks. In most of these occurrences the thorium-bearing minerals occur in only trace amounts and consequently warrent little further consideration. More data are needed to determine the possibilities of byproduct recovery of thorium-bearing minerals from several of the gold and tin placers.

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Publication type Report
Publication Subtype USGS Numbered Series
Title Preliminary summary review of thorium-bearing mineral occurrences in Alaska
Series title Trace Elements Memorandum
Series number 339
DOI 10.3133/tem339
Year Published 1952
Language English
Publisher U.S. Geological Survey
Description Report: 28 p.; 1 Plate: 19.61 x 15.26 inches
Country United States
State Alaska
Additional Online Files (Y/N) Y
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