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Research about Pershing County, Nevada

Source-linked reports with geographic coverage including Pershing County, Nevada.

11 recordsLinked to original sources
USGS2014

Magmatism, metasomatism, tectonism, and mineralization in the Humboldt Range, Pershing County, Nevada

Introduction The Humboldt Range, Pershing County, Nevada, predominantly consists of Mesozoic igneous and sedimentary rocks that were modified several times by magmatism, metasomatism, and tectonism, and contain a variety of metallic (Ag, Au, Pb, Zn, Sb, W, Hg) and non-metallic (dumortierite, pinite, fluorite) mineral deposits (Knopf, 1924; Kerr and Jenney, 1935; Kerr, 1938; Cameron, 1939; Campbell, 1939; Kerr, 1940; Page et al., 1940; Johnson, 1977; Vikre, 1978; 1981; Crosby, 2012). Early Triassic Koipato Group volcanic rocks, which are widely exposed in the range, have been altered to quartz, muscovite (sericite), chlorite, pyrite, and other minerals during emplacement of Mesozoic intrusions and by crustal thickening. Most hydrothermal alteration of volcanic rocks and formation of mineral deposits involved externally derived water and other volatiles, although some volcanic strata were apparently altered by pore or dehydration water. Cospatial hydrothermal mineral assemblages and associations, produced by events widely spaced in time, are difficult to separate because of common mineralogy (quartz, sericite, and pyrite), partial to complete recrystallization, thermally compromised Ar geochronology, and lack of comprehensive investigations of volatile sources and deformational fabric. Distinguishing between metasomatic and metamorphic processes that affected rocks in the Humboldt Range is not straightforward.

Nevada↗
USGS1994

Modeling fluid flow and heat transfer at Basin and Range faults: preliminary results for Leach hot springs, Nevada

The hydrothermal systems of the Basin and Range Province are often located at or near major range bounding normal faults. The flow of fluid and energy at these faults is affected by the advective transfer of heat and fluid from an to the adjacent mountain ranges and valleys, This paper addresses the effect of the exchange of fluid and energy between the country rock, the valley fill sediments, and the fault zone, on the fluid and heat flow regimes at the fault plane. For comparative purposes, the conditions simulated are patterned on Leach Hot Springs in southern Grass Valley, Nevada. Our simulations indicated that convection can exist at the fault plane even when the fault is exchanging significant heat and fluid with the surrounding country rock and valley fill sediments. The temperature at the base of the fault decreased with increasing permeability of the country rock. Higher groundwater discharge from the fault and lower temperatures at the base of the fault are favored by high country rock permabilities and fault transmissivities. Preliminary results suggest that basal temperatures and flow rates for Leach Hot Springs can not be simulated with a fault 3 km deep and an average regional heat flow of 150 mW/m 2 because the basal temperature and mass discharge rates are too low. A fault permeable to greater depths or a higher regional heat flow may be indicated for these springs.

Nevada↗
USGS1978

Principal facts for a gravity survey of the Fly Ranch Extension Known Geothermal Resource Area, Pershing County, Nevada

During July 1977, forty-four gravity stations were obtained in the Fly Ranch Extension Known-Geothermal Resource Area and vicinity, northwestern Nevada. Elevations for three stations were estimated from lake bed topographic contours. Horizontal and vertical positions for stations FREX33 through FREX43 were determined from plane-table surveying. Positions for the remaining stations were taken from benchmarks or spot elevations shown on U.S. Geological Survey topographic maps at scales of 1:24,000.

Nevada↗