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Research about Humboldt County, Nevada

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

25 records · Page 2Linked to original sources
USGS1971

Geochemical, aeromagnetic, and generalized geologic maps showing distribution and abundance of lead and silver, Golconda and Iron Point quadrangles, Humboldt County, Nevada

Detailed geologic and geochemical studies of the four 7 1/2-minute quadrangles that make up the Edna Mountain 15-minute quadrangle in Humboldt County, Nevada, were begun during the 1969 summer field season. The objectives of the project are to map the geology of this struct urally complex area at 1:24·,000 scale and to determine the regional distribution and abundance of metals in rocks of the are\3. and the factors that control the distribution and abundance of those metals. Tungstenbearing hot-spring tufa, metalliferous black shale in Ordovician rocks, base-metal and barite deposits in Paleozoic sedimentary rocks, and copper-molybdenum in granodiorite plutons of Cretaceous age occur in the Edna Mountain area. None of these deposits have been of much economic significance, although tungsten was mined from the hot-spring deposits during World War II. The numerous occurrences of mineralized ground, however, along with the broad spectrum of types of mineralization, intensity of alteration, structural complexity, and abundance of intermediate to silicic igneous intrusive rocks suggest that concealed or heretofore unrecognized mineral deposits may exist in the area. Integrated geologic, geochemical, and geophysical studies on a district- wide scale might improve our un~erstanding of the factors that control the distribution, methods of emplacement, and spatial and genetic relationships (if any) of these different types of deposits. We hope that broad target areas or guidelines for mineral exploration in th.is area may be identified. This series of maps shows the distribu t ion and abundance of mercury, arsenic, antimony, tungsten, gold, copper, l ead, and s ilver related to a geologic and aeromagnetic base in the Golconda and Iron Point 7 1/2-minute quadrangles. All samples are rock samples; most are f rom shear or f ault zones, fractures, jasperoid, breccia reefs, and altered rocks . All the samples were prepared and analyzed in truck-mounted laboratories at Wi nnemucca, Nevada. Arsenic , tungs t en, copper, lead, and si lver were determined by semiquantitative spectrogr aph i c methods by D. F. Siems and E. F. Cooley . Mercury and gold were determined by atomi c absorption methods and antimony was determined by a colorimetric method by R. M. O'Leary, M. S. Erickson, and others.

Nevada↗
USGS1964

Geology and mineral deposits of the Osgood Mountains quadrangle, Humboldt County, Nevada

The Osgood Mountains quadrangle is in north-central Nevada northeast of Winnemucca, the principal town in the region. The quadrangle includes two north-northeast-trending mountain ranges, the Osgood Mountains on the east and the Hot Springs Range on the west, which are separated by a narrow valley and are bounded on the east and west by broad alluviated basins. Large deposits of tungsten and gold have been mined in the northeastern part of the Osgood Mountains; small deposits of quicksilver, lead, zinc, and gold are known in the Hot Springs Range, and some prospecting has been done on barite deposits in the Osgood Mountains. Some quartzite beds are potential sources of silica.

Nevada↗
USGS1955

A gold-scheelite-cinnabar placer in Humboldt County, Nevada

Gold, scheelite, and cinnabar in amounts that might be profitably extracted are found in a placer deposit in the Dutch Flat mining district in north-central Nevada. These materials are the products of at least two and possibly three stages of metallogenic activity recorded in the district. The gold and perhaps most of the scheelite were derived from quartz veins that cut a small granodiorite stock and lower Paleozoic sedimentary rocks. Part of the scheelite may have been derived from contact-metamorphic deposits associated with the granodiorite stock. The cinnabar came from a shear zone that is later than the quartz veins. The proximity of the placer to the source of the minerals is the factor that made a significant concentration of these minerals possible. Incomplete sampling of the placer indicates an average value of $1.50 per cubic yard in combined gold, tungsten, and mercury based on the price of these metals in August 1954.

Nevada↗
USGS1951

Virgin Valley opal district, Humboldt County, Nevada

The Virgin Valley opal district, Humboldt County, Nevada, is near the Oregon-Nevada border in the Sheldon Game Refuge. Nineteen claims owned by Jack and Toni Crane were examined, sampled, and tested radiometrically for uranium. Numerous discontinuous layers of opal are interbedded with a gently-dipping series of vitric tuff and ash which is at least 300 ft thick. The tuff and ash are capped by a dark, vesicular basalt in the eastern part of the area and by a thin layer of terrace qravels in the area along the west side of Virgin Valley. Silicification of the ash and tuff has produced a rock that ranges from partly opalized rock that resembles silicified shale to completely altered rock that is entirely translucent, and consists of massive, brown and pale-green opal. Carnotite, the only identified uranium mineral, occurs as fracture coatings or fine layers in the opal; in places, no uranium minerals are visible in the radioactive opal. The opal layers are irregular in extent and thickness. The exposed length of the layers ranges from 8 to 1, 200 ft or more, and the thickness of the layers ranges from 0. 1 to 3. 9 ft. The uranium content of each opal layer, and of different parts of the same layer, differs widely. On the east side of Virgin Valley four of the seven observed opal layers, nos. 3, 4, 5, and 7, are more radioactive than the average; and the uranium content ranges from 0. 002 to 0. 12 percent. Two samples, taken 5 ft apart across opal layer no. 7, contained 0. 003 and 0. -049 percent uranium. On the west side of the valley only four of the fifteen observed opal layers, nos; 9, , 10, 14, and 15, are more radioactive than the average; and the uranium content ranges from 0. 004 to 0. 047 percent. Material of the highest grade was found in a small discontinuous layer of pale-green opal (no. 4) on the east side of Virgin Valley. The grade of this layer ranged from 0. 027 to 0. 12 percent uranium.

Nevada↗