Radioactivity of selected rocks and placer concentrates from northeastern Alaska

White, Max Gregg

doi:10.3133/cir195

Cited by 6 publications

(5 citation statements)

References 1 publication

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“…Previous radiometric and mineralogic studies of panned concentrates and granite bedrock samples from this area have been reported by White ( 1952). The samples contain a notable percentage of uranium, which appears to be entirely in the biotite and thus can be increased by heavymineral concentration.…”

Section: Economic Geologymentioning

confidence: 84%

Geology of the western Romanzof Mountains, Brooks Range, northeastern Alaska

Sable¹

1977

Professional Paper

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The western Romanzof Mountains cover a remote 700-square-mile area in the Brooks Range, northeastern Alaska. The area is topographically rugged and geologically diverse; it contains a gramtlc pluton, low-grade metamorphic rocks, sedimentary rocks and mafic igneous rocks, as well as glacial features.Rocks of sedimentary origin, from o1dest to youngest are: l. Neruokpuk Formation (Precambrian, Cambrian, and pre-Mississippian), more than 4,000 feet thick, consists of units of the greenschist facies, including quartziticand schistose-feldspathic to quartzose graywacke; phyllite, argillite, slate; minor chert; and limestone. The succession of units in parts of the area is uncertain. Correlations of these units with each other and with other units in the eastern Brooks Range are provisional. 2. Katakturuk Dolomite (Devonian or older), silicified carbonate rocks, mostly dolomite, with minor dark shale, carbonate conglomerate and breccia beds, pisolite and oolite beds. Probably more than 1,000 feet thick. 3. Kekiktuk Conglomerate and Kayak(?) Shale (Mississippian), a single map unit, 0(?)-420 feet thick, contains quartzite, interbedded dark shale, and some pebbleto boulder-conglomerate in the locally absent lower part (Kekiktuk), and, in its uppermost part, dark shale (Kayak(?)). The unit overlies the Neruokpuk and Katakturuk with angular unconformity, which may reflect either a pre-Kayak(?) or pre-Kekiktuk hiatus or both. 4. Lisburne Group, almost entirely carbonate rocks, is 600-800 feet thick in the northern part of the area and probably 1,200 feet thick in the southern part. Alapah Limestone (Upper Mississippian) of this group, as much as 560 feet thick, includes gray sandy, crystalline, and cherty limestones; minor dark shale; and, in the upper part, dark cherty carbonate rocks. Dark shaly and cherty carbonate rocks abo constitute the lower part of the group in the southern part of the area. The lower contact is gradational with the Kayak(?) Shale. The Wahoo Limestone (Pennsylvanian) conformably overlies the Alapah, is 0-200+ feet thick, and is characterized by light-gray crinoidal limestones in its upper pan. 5. Sadlerochit Formation, consisting of two members: the Echooka Member (Upper Permian) of iron-stained orthoquartzite and dark slate, 175-240 feet thick, which unconformably overlies the Wahoo and Alapah Limestones; and the Ivishak Member (Lower Triassic), consisting of a shale unit of dark shale, slate, and minor quartzite averaging 400 feet in thickness, and a quartzite unit, 700 feet thick, mostly orthoquartzite with minor shale and conglomerate. The basal clastics were probably shed from the north. 6. Shublik Formation (Middle and Upper Triassic), 60Q-700 feet thick, the thin phosphatic sandstone member is overlain by dark phosphatic limestones and limy shales of the limestone member.

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Section: Economic Geologymentioning

confidence: 84%

Geology of the western Romanzof Mountains, Brooks Range, northeastern Alaska

Sable¹

1977

Professional Paper

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“…Preliminary radiometric examination of concentrates taken from placers in 1952 did not reveal even traces of the radioactivity that was previously reported (White, 1952, White (1952, p. 8 and table 3) that the radioactivity of an older placer concentrate from Gold Bench is due to "traces of uranium'-bea'ring thorianite(?). " The source of the gold mined from the gravels at Gold Bench is unknown; however, Maddren (1913, p. 106) suggests that the source area of the gold is in the mountains on the south side of the South Fork of the Koyukuk River.…”

Section: Introductionmentioning

confidence: 79%

Preliminary summary of reconnaissance for uranium and thorium in Alaska, 1952

Wedow¹

1953

Circular

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“…One analyzed sample of granite from an unknown locality in the batholith contains 17 ppm chemical uranium and 52 ppm thorium (A. H. Lachenbruch and J. H. Sass, personal commun., 1976), more than four times as much uranium as the average granite. Most of the uranium may be within the biotite crystals (White, 1952). Stream-sediment samples suggest that the uranium may be concentrated in the interior of the Okpilak batholith, and is less abundant at its margins and in the Jago and South stocks.…”

Section: Uraniummentioning

confidence: 98%

Preliminary geologic and mineral resource maps (excluding petroleum), Arctic National Wildlife Range, Alaska

Brosge¹,

Reiser²

1976

Open-File Report

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The geologic divisions of the Wildlife Range correspond generally to its physiographic divisions. The Romanzof Mountains form the backbone of the Range. Low linear ranges form the mountain front north of the Romanzofs, while rugged mountains and broad valleys make up the Brooks Range to the south. The still lower Arctic foothills and coastal plain and the Porcupine plateau form the northern and southern extremities of the Wildlife Range. The Arctic coastal plain and foothills are covered with unconsolidated deposits and are underlain by Cretaceous and Tertiary sediments that dip regionally northward and were probably derived from erosion of the ancestral Brooks Range. The low northern mountains are characterized by long open to recumbent east-trending folds. In the east they consist mostly of lower Paleozoic or Precambrian rocks, and in the west are mostly of upper Paleozoic and Mesozoic rocks, with older rocks exposed in the cores of the folds. The Romanzof Mountains are a broad anticlinorium of slightly metamorphosed Precambrian sedimentary rocks, overlain by lower Paleozoic rocks and intruded by granite. The anticlinorium includes large areas of lower Paleozoic chert and interbedded volcanic rocks and limestone, whereas in the folded mountains to the north, volcanic rocks are less abundant and limestone and dolomite are more abundant.

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Radioactivity of selected rocks and placer concentrates from northeastern Alaska

Cited by 6 publications

References 1 publication

Geology of the western Romanzof Mountains, Brooks Range, northeastern Alaska

Geology of the western Romanzof Mountains, Brooks Range, northeastern Alaska

Preliminary summary of reconnaissance for uranium and thorium in Alaska, 1952

Preliminary geologic and mineral resource maps (excluding petroleum), Arctic National Wildlife Range, Alaska

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