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William N. Sharp

Publications and source records attributed to William N. Sharp.

At least 19 recordsLinked to original sources
USGS2018

Zinc- and Y-group-bearing senaite from St Peters Dome, and new data on senaite from Dattas, Minas Gerais, Brazil

A Zn- and Y-group-bearing senaite, formulated as AM 21 O 38 (Pb 0.63 Na 0.46 Ba 0.11 ) Σ1.20 (Ti 14.64 Zn 1.74 Y‒group REE 0.70 Mn 0.38 Nb 0.20 Sn 0.03 Zr 0.03 Th 0.02 ) Σ20.9 O 38 , a member of the crichtonite group, is a newly characterized phase associated with murataite at the St Peters Dome area, Colorado. The Zn- and Y-group-bearing senaite is uranium-free and nonmetamict, but otherwise is comparable to known senaites and davidites in X-ray diffraction pattern, symmetry, and structure. The REE distribution shows a strong dominance of Y and the Y-group REE which are present in M (1). Megascopically, the mineral is black, submetallic, and opaque; in polished section it appears to be white and moderately bright compared with murataite. Cleavage is absent but twinning on {52 0} is present. Senaite and hitherto unreported zinc-bearing senaite from Dattas, Diamantina, Minas Gerais, Brazil, have the following respective structural formulas as determined by electron microprobe: (Pb 0.76 Sr 0.20 La 0.08 Ce 0.07 Ba 0.04 ) Σ1.15 (Ti 12.89 Mn 0.88 Y 0.59 Zn 0.12 Mg 0.07 Nb 0.03 Cr 0.02 Th 0.02 ) Σ20.61 O 38 and (Pb 0.89 Ba 0.15 Ce 0.02 Sr 0.02 ) Σ1.08 (Ti 14.57 Zn 1.76 Na 0.63 Mn 0.50 Y 0.28 Nb 0.14 Mg 0.04 Cr 0.02 ) Σ20.83 O 38

Dattas, Minas Gerais↗
USGS1983

Aeromagnetic map of the Powderhorn wilderness study area and Cannibal Plateau Roadless Area, Gunnison and Hinsdale counties, Colorado

The Powderhorn Wilderness Study Area (51,000 acres or 20,640 hectares) and the contiguous Cannibal Plateau Roadless Area (29,500 acres or 11,959 hectares) are on the Gunnison County-Hinsdale County boundary, approximately 50mi (80 km) southwest of Gunnison and a few miles east of Lake City, Colo. Part of the area has been known as the Powderhorn Primitive Area. The mineral resource potential of the study area has been assessed by the U.S. Geological Survey and the U.S. Bureau of Mines; this assessment involved, besides the geologic study and economic appraisal (Sharp and others, 1983), a geophysical survey (this report) by the Geological Survey, and a geochemical survey (Sharp and Lane, 1983) by the Geological Survey and the Bureau of Mines.

Colorado↗
USGS1980

Preliminary report on the mineral resources of the Powderhorn Instant study area, Gunnison and Hinsdale counties, Colorado

The Powderhorn Instant Study Area covers approximately 51,000 acres of land under BLM administration located about 80 km (50 mi) southwest of Gunnison, Colorado. A mineral resource survey, made in 1979 by the U.S. Geological Survey and the U.S. Bureau of Mines, indicates that both the mineral potential and the energy potential for the Powderhorn Instant Study Area are low. This report is based on geologic and geochemical investigations, examination of prospects, and an aeromagnetic survey. Spectrographic analyses were made of approximately 120 stream-sediment and rock samples. No mining districts are located within the study area.

Colorado↗