USGS Science⌕ Search

Geology topics

Research about Nevada

Source-linked reports with geographic coverage including Nevada.

At least 1,333 records · Page 74Linked to original sources
USGS1957

Geology of Gabbs and vicinity, Nye County, Nevada

The geologic map of Gabbs and vicinity covers approximately 105 square miles of the northwestern part of the Paradise Peak quadrangle. The present report stresses the igneous, metamorphic, and structural geology. The map published at this time shows, (1) the distribution of igneous rocks in the area, (2) the relationship of these igneous rocks to the areas of magnesium mineralization, and (3) the relationship of the igneous rocks to other areas of mineralization where tungsten and base metal elements are found.

Nevada↗
USGS1956

Geologic map of the Gabbs magnesite and brucite deposits, Nye County, Nevada

During World War II the magnesite deposits at Gabbs, in northwestern Nye County, Nevada, were the source of ore for the world's largest magnesium metal plant. This Government-owned plant, located at Henderson, near Las Vegas, Nevada, close to the source of power at Boulder Dam, produced 81,272 tons of metal from 920,000 tons of ore during the period September 1942 to November 1944. Owing to the oversupply of magnesium toward the end of the war, mine production as a source for magnesium metal was curtailed and was finally stopped in November 1944. As of January 1947, 241,000 tons of magnesite from this area had been used in the production of refractories and oxychloride cement. Brucite deposits associated with the magnesite have been mined almost continuously since 1935 and had yielded 246,000 tons of ore through January 1945 for use in the refractoies industry of Ohio.

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↗
USGS1954

Hydraulic characteristics of aquifers penetrated by irrigation wells in the vicinity of Orovada, Humboldt County, Nevada, 1953

During the period April 21-23, 1953, a pumping test was made on several irrigation wells penetrating alluvium about a mile southwest of Orovada, Nev., in order to determine the hydraulic characteristics of the aquifers commonly penetrated by wells in that vicinity. The test was made by the writer, engineer, and J.L Poole, geologist, United States Geological Survey, as part of an investigation of the ground-water resources of Nevada being by the U.S Geological Survey in cooperation with the State Engineer. Much recent interest in the development of underground water by pumping in the Orovada area made it desirable to make the pumping test in order to obtain data that might be helpful in the proper planning of future development.

Nevada↗
USGS1953

Radioactive deposits of Nevada

Thirty-five occurrences of radioactive rocks had been reported from Nevada prior to 1952. Twenty-five of these had been investigated by the U. S. Geological Survey and the U. S. Atomic Energy Commission. Of those investigated, uranium minerals were identified in 13; two contained a thorium mineral (monazite); the source of radioactivity on 7 properties was not ascertained; and one showed no abnormal radioactivity. Of the other reported occurrences, one is said to contain uraniferous hydrocarbons and 9 are placers containing thorian monazite. Pitchblende occurs at two localities; the East Walker River area, and the Stalin's Present prospect, where it is sparsely disseminated in tabular bodies cutting granitic rocks. Other uranium minerals found in the state include: carnotite, tyuyamunite, autunite, torbernite, gummite, uranophane, kasolite, and an unidentified mineral which may be dumontit. Monazite is the only thorium mineral of possible economic importance that has been reported. From an economic standpoint 9 only 4 of the properties examined showed reserves of uranium ore in 1952; these are: the Green Monster mine, which shipped 5 tons of ore to Marysvale, Utah, during 1951, the Majuba Hill mine, the Stalin's Present prospect, and the West Willys claim in the Washington district. Reserves of ore grade are small on all of these properties and probably cannot be developed commercially unless an ore-buying station is set up nearby. No estimate has been made of thorium reserves and no commercial deposits of thorium are known.

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↗