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Source-linked reports with geographic coverage including Nevada.

At least 1,063 records · Page 59Linked to original sources
USGS1976

Lithium in sediments and rocks in Nevada

Reconnaissance geochemical sampling has been conducted by the Lithium Resource Program of the United States Geological Survey for much of the Western U.S. Sediment, rock, and brine samples have been collected in many states, but this report describes just those solid samples collected in Nevada. Further reports by other members of the Lithium Program will describe water samples from Nevada and samples from other states. The purpose of the sampling program was to determine if areas of anonalous lithium could be recognized by reconnaissance surface sampling. The results, however, have been indeterminate because most large lithium deposits occur at depth and appear to be formed when deeply buried. Many may not manifest themselves at the surface at all . Nonetheless, the data derived during the surface sampling program will be presented in this report.

Nevada↗
USGS1976

Principal facts for gravity stations in the Nevada portion of the Mariposa 2 degrees sheet

The northeast corner of the Mariposa 2° topographic sheet occurs within the State of Nevada (fig. 1) and includes parts of Mineral and Esmeralda Counties. In this area field crews of the U.S. Geological Survey have established 95 gravity observations in conjunction with geologic studies being made as part of the Nevada tectonic project. The principal gravity reference base station was Tonopah J, located at the Nye County Airport, 8 miles (12.9 km) east of Tonopah, Nev. The observed gravity value for this base is 979,476.15 mGals (Department of the Air Force, written commun., 1969).

Nevada↗
USGS1976

Water resources data for Nevada, water year 1975

Water resources data for the 1975 water year for Nevada consist of records of discharge and water quality of streams; stage, contents, and water quality of lakes and reservoirs; and water levels in wells. This report contains discharge records for 120 gaging stations; stage and contents for 21 lakes and reservoirs; water-quality data for continuing-record stations at 23 stream sites and for partial-record stations at 5 stream sites and 2 lake sites; and water levels for 62 observation wells. Also included are 121 crest-stage partial-record stations and 13 low-flow partial-record stations. Additional water data were collected at various sites, not part of the systematic data collection program, and are published as miscellaneous measurements. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State and Federal agencies in Nevada.

Nevada↗
USGS1976

Age and origin of the Darrough Felsite, southern Toiyabe Range, Nevada

The name Darrough Felsite was originally assigned to a body of fine-grained quartzofeldspathic igneous rock probably greater than 3 km thick that is exposed continuously over 100 km 2 in the southern Toiyabe Range of central Nevada. The Darrough was supposed to consist mostly of intrusive rocks of probable Permian age. Reexamination of parts of the Darrough Felsite indicates that it is Tertiary and has no genetic affiliation to pre-Tertiary sedimentary and volcanic rocks of the Toiyabe Range. The Darrough constitutes an enormously thick succession of crystal-lithic tuff, tuff breccia, crystal tuff, and volcanogenic sedimentary breccia and sandstone. The tuffaceous rocks are strongly compacted where ash particles are the dominant constituent but are much less compacted where lithic fragments and crystals constitute a rigid framework. Much of the Darrough Felsite may have undergone extensive siliciflcation, probably as a postcompaction event. Contact relations of the Darrough Felsite indicate that it is younger than pre-Tertiary rocks of the southern Toiyabe Range and the Ophir pluton, here dated at 53.9 m.y. (K-Ar, biotite). Three K-Ar ages of minerals from tuff of the Darrough are 26.1, 22.7, and 22.3 m.y., suggesting a middle Tertiary age. A large dike intruding the Darrough. previously assigned a Jurassic age, gives a K-Ar-biotite age of 29.4 m.y. We tentatively interpret the Darrough Felsite to represent an accumulation of ash and breccia flows in a volcanotectonic depression.

Nevada↗
USGS1976

Bootstrap window, Elko and Eureka Counties, Nevada

The Bootstrap window in the Roberts Mountains thrust of north-central Nevada contains a 1,500-ft (460-m)- thick autochthonous section of carbonate assemblage rocks. These carbonate rocks include the upper part of the Roberts Mountains Formation and an unnamed limestone of Devonian age. They contain abundant material that must have been deposited in or near a reef. Allochthonous chert and shale of the siliceous assemblage, presumably Ordovician and Silurian in age, are present around the window and in a north-trending graben within the window. The Paleozoic rocks contain altered dikes, most of which may originally have been granodioritic. The localized recrystallization in the Paleozoic rocks probably occurred during dike emplacement. Sometime after the intrusion; both the dikes and their host rocks were epithermally altered. Some gold has been mined, and relatively high gold values (≥1 ppm) occur in rocks of the siliceous assemblage in and near the northern part of the steep north-trending fault zone on the west side of the graben. Areas of secondary alteration and of high values of silver and mercury are more widespread than the area of high gold values. The highest concentrations of silver and mercury, however, are also found near the same gold-bearing fault zone.

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