Abstract: Summaries of the geology and mineral deposits, and appraisals of the uranium possibilities of the various regions of Alaska are presented in this report.

From abstract: Gypsum-bearing rocks crop out in Gypsum and Yellow Jacket Gulches, on Sheep Mountain, which is about 90 miles northeast of Anchorage, Alaska. The gypsiferous rock occurs in deposits of irregular shape in the greenstone. Both the gypsiferous rock and the greenstone are hydrothermal alteration products of the volcanic rocks of Jurassic age which comprise the bulk of the mountain. Near-surface samples of the gypsiferous rock contained an average of 25 to 30 percent gypsum ; some contained as much as 50 percent. Quartz, alunite, clay, sericite, and pyrite are contaminating constituents of the ore. Six of the largest and most accessible of the gypsum deposits were mapped and calculations show that three of the deposits contain an aggregate of approximately 311,000 short tons of indicated gypsiferous rock and four of the deposits contain 348,000 short tons of inferred gypsiferous rock.

Abstract: A suite of 50 rock specimens, collected by the 1947 Washburn Mount McKinley Expedition, was scanned radiometrically. The maximum radioactivity observed in any one of the specimens was about twice background. Radiometric analyses of the most radioactive samples show that a sample of vein quartz coated with manganese oxide contains 0.009 percent equivalent uranium and that the maximum equivalent uranium content of granitic rock types is .004 percent. The radioactivity of the manganese-stained quartz is probably due to traces of uranium in the manganese mineral, whereas that of the granitic rocks is due to radioactive accessory minerals.

From abstract: Radiometric reconnaissance in several districts of the Alaska Railroad-Iliamna region during 1951 found no radioactive material in excess of 0.002 percent equivalent uranium associated with certain lode deposits that previously were deemed favorable for the occurrence of uranium because they contain mineral assemblages similar to uranium-producing lodes elsewhere.

Abstract: No radioactive material in excess of 0.002 percent equivalent uranium was found during 1951 in a reconnaissance of possibly favorable lode deposits in the Nuka Bay, Moose Pass-Hope, and Girdwood areas of the Gulf of Alaska region.

From abstract: Radiometric reconnaissance during the summer of 1951 of 47 abandoned lode mines and prospects in the predominantly mesothermal mineral belt in the central and southern parts of southeastern Alaska revealed radioactivity in excess of 0.005 percent equivalent uranium at only one locality.

The following report discusses radioactive results found in 4 samples of gneissic granite of 13 samples collected from the Mount Michelson area of northeastern Alaska. A mineralogic study of all heavy-mineral fractions having more than 0.01 percent equivalent uranium indicates that the radioactive material apparently is confined to biotite, which in one sample contains 1.19 percent uranium.

Report discussing a study in which a suite of 50 rock specimens collected by the 1947 Washburn Mount McKinley Expedition was scanned radiometrically.

A report regarding a reconnaissance performed Along the Upper Porcupine River, Northeastern Alaska for radioactive deposits.

The following report presents results of radiometric and mineralogic studies made on 13 samples taken from the Mount Michelson area, Alaska.