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E. J. Young

Publications and source records attributed to E. J. Young.

9 recordsLinked to original sources
USGS1982

Uranium in Wheeler Basin, Grand County, Colorado

Two kinds of radioactive anomalies are found in Wheeler Basin, both of which consist of biotite concentrations in Precambrian rocks, but the ones in migmatized biotite gneiss contain uraninite and the ones in Silver Plume Granite probably do not. At least 18 new uranium occurrences were found, most of which are less than a square meter. These discoveries enlarge the uraniferous area reported by Young and Hauff in 1975. Uranium in these biotite concentrations occurs in several modes: as uraninite grains; in accessory minerals, such as zircon; in fractures in plagioclase; and along grain boundaries and in cleavage openings in mica. Uranium mineralogy in the fractures, grain boundaries, and micas is not known. Yellow, secondary uranium minerals are seen locally on outcrop. Relative to crustal abundance, the radioactive biotite concentrations in migmatized biotite gneiss show depletion in Ca, Sr, Na, and, locally, Cu, but pronounced enrichment in U and Mo, and moderate enrichment in Pb, Ag, Th, and REE. The radioactive biotite concentrations in the Silver Plume Granite show pronounced enrichment in Th, and moderate enrichment in U, Sn, Zr, and Ag. Enrichment in light REE predominates over heavy REE. As U is more abundant in biotite concentrations in migmatized biotite gneiss than in biotite concentrations in Silver Plume Granite, I have concluded that U in the migmatized biotite gneiss was present before intrusion of the Silver Plume Granite, and that metamorphic effects of the Silver Plume intrusion remobilized U to form pockets of enrichment (biotite concentrations).

Open-File Report↗
USGS1975

An occurrence of disseminated uraninite in Wheeler Basin, Grand County, Colorado

Disseminated uraninite occurs in Wheeler Basin, Grand County, Colo., about 5 mi (8 km) southeast of Monarch Lake, in Precambrian metamorphic rocks consisting of migmatized gneiss and mixed gneiss and pegmatite. An intrusion of Precambrian Y Silver Plume Granite lies within 400 ft (122 m) of the occurrence. The disseminated uraninite is confined to parts of the host rock that are rich in biotite; highest grade found was 0.73 percent uranium. The disseminated uraninite occurs as cubes and grains, generally from 0.1 to 0.3 mm across. Unit cell edge of the uraninite, ≈ 5.48 A, suggests its pegmatitic origin. The origin of the uraninite disseminations is attributed by us to remobilization and concentration of elements during metamorphism caused by the intrusion of Silver Plume Granite. Uranium and lead isotopic analyses by K. R. Ludwig of uraninite and monazite from biotite concentrations confirm an apparent age of 1,450±20 m.y. for these minerals. This age is equivalent to that reported for the Silver Plume Granite. Although the Wheeler Basin occurrence is small in size, it has many similarities to the Rossing uranium deposit in South-West Africa.

Colorado↗
USGS1975

Absolute age of disseminated uraninite in Wheeler Basin, Grand County, Colorado

Uranium and lead isotopic analyses of monazlte and uraninite from the disseminated uraninite occurrence at Wheeler Basin, Grand County, Colo., indicate that these minerals formed 1,446±20 m.y. ago. This time correlates well with intrusion of the Silver Plume Granite. The uraninite and monazite were also affected by a later disturbance at 880±130 m.y., but show essentially no effects of subsequent events. This secondary disturbance may have been due to intrusion of dikes related to the Pikes Peak batholith, dated at 1,041±13 m.y. ago.

Colorado↗
USGS1968

Spectrographic date on cores from the Pacific Ocean and the Gulf of Mexico

Average quantitative spectrographic data are presented for V, Ti, Zr, Ni, Co, Sc, Cr and La in the following Pacific deep-sea cores: siliceous ooze (3), red clay (6), volcanic mud (3), calcareous ooze (3) and one manganese nodule, and in 23 near-shore cores, mostly from the Gulf of Mexico.

Geochimica et Cosmochimica Acta↗