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Geology topics

P. J. Graff

Publications and source records attributed to P. J. Graff.

6 recordsLinked to original sources
USGS1992

Metallogenic map of volcanogenic massive sulfide occurrences in Wyoming

Volcanogenic massive sulfide occurrences of Late Archean age and Early Proterozoic age occur in metavolcanic and associated metasedimentary rocks in southeastern, eastern, and central Wyoming. Vein deposits in Archean volcanic terrane have accounted for a large part of the gold production in the State (Miners Delight, locality 8). Past production from all massive sulfide occurrences in the State is poorly known, but it probably did not exceed $13 million at current metal prices. The bulk of the production was from gold mines in the southern Wind River Range (localities 8 and 17). For the most part, the host rocks of the massive sulfide occurrences have been metamorphosed to amphibolite facies. As a result, the depositional environments are, in many cases, difficult to determine. For purposes of discussion, the occurrences are classified by geologic age.

Wyoming↗
USGS1991

Geology and mineralization of the Wyoming Province

The Wyoming Province is an Archean craton which underlies portions of Idaho, Montana, Nevada, Utah, and much of Wyoming. The cratonic block consists of Archean age granite-gneiss with interspersed greenstone belts and related supracrustal terranes exposed in the cores of several Laramide uplifts. Resources found in the Province and in the adjacent accreted Proterozoic terrane include banded iron formation, Au, Pt, Pd, W, Sn, Cr, Ni, Zn, Cu, and diamonds. The Province shows many similarities to the mineral-rich cratons of the Canadian shield, the Rhodesian and Transvaal cratons of southern Africa, and the Pilbara and Yilgarn blocks of Western Australia, where much of the world's precious and strategic metal and gemstone resources are located.

Conference Paper↗
USGS1977

Preliminary report on radioactive conglomerates of Middle Precambrian age in the Sierra Madre and Medicine Bow Mountains of southeastern Wyoming

Middle Precambrian miogeosynclinal metasedimentary rocks o# the Sierra Madre and Medicine Bow Mountains of southeastern Wyoming contain radioactive quartz-pebble conglomerates of possible economic interest. These conglomerates do not contain ore-grade uranium in surface outcrops, but an earlier report on the geochemistry of the Arrastre Lake area of the Medicine Bow Mountains shows that ore-grade deposits may be present in the subsurface. This report describes the stratigraphy of the host metasedimentary rocks and the stratigraphic setting of the radioactive conglomerates in both the Sierra Madre and Medicine Bow Mountains, and compares these rock units with those of the Blind River-Elliot Lake uranium district in Canada. The location of radioactive .conglomerates is given so that further exploration may be undertaken by interested parties.

Wyoming↗