SEARCH · Geology Reports

Results for “Nevada Bureau of Mines and Geology Open File Report”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

10 recordsLinked to original sources

USGS2020

Reconnaissance map of the Cenozoic geology in the Carlin basin area, Elko and Eureka counties, Nevada

The middle Miocene Carlin sedimentary basin encompasses a large area between the Adobe Range to the east, the Piñon Range to the south, the southern Independence Mountains and Marys Mountain to the west, and Swales Mountain to the north. The town of Carlin is in the southern part of the basin. The geologic map includes detailed to more reconnaissance mapping of Cenozoic units in the main part of the basin, including different facies of the middle Miocene Humboldt Formation. The mapping was part of a broader study of the Miocene and younger paleogeographic evolution of the region. Earlier work obtained numerous 40 Ar/ 39 Ar and tephra correlation dates on sedimentary and volcanic units in the basin. The basin connected to the east into the Elko sedimentary basin and to the northwest and northeast into similar smaller basins between present-day mountain ranges. Early sediments, largely fluvial, began to accumulate in the lowlands between the surrounding ranges at about 16.5 Ma. The sediments were derived from Paleozoic sedimentary and middle Tertiary volcanic units in the nearby highlands, and flow patterns indicate a general southward flow towards present-day Pine Valley. The eruption of the Palisade Canyon–Marys Mountain rhyolite flows at the southwest end of the basin at 15.3 Ma blocked the southward flow, and a lake began to form in the basin. As the lake grew in extent, sedimentary units around the fringes of the lake included a mixture of inflowing fluvial sediments mixed with the pyroclastic-fall, ash-rich sediments deposited in the lake. The lake margin expanded, and stratigraphic sections record the progressive transition from fluvial to mixed fluvial and lacustrine, and finally to entirely lacustrine. The volcanic rock dam was breached at about 14.7 Ma, the lake drained, and fluvial sediments blanketed the entire basin for an unknown period of time after that. Sedimentation progressively buried existing highlands and bridged gaps between adjacent basins. For example, the Carlin and Elko basins connected across the southern Adobe Range. Normal faulting produced numerous, mostly north- to north-northeast-striking faults that cut the sedimentary units and surrounding highlands largely after sedimentation ceased. The largest fault formed in the eastern third of the basin and tilted all of the sedimentary units in the western two-thirds of the basin, as well as the eastern part of Marys Mountain, to the east. Some offset took place during sedimentation. Many other normal faults of smaller extent and offset cut the sedimentary units. The integration of streams draining the Elko and Carlin basins began after about 9.8 Ma. The streams, which together comprised the early stages of the Humboldt River, flowed regionally southwestward beyond the Carlin basin. As many as thirteen, downward-stepping strath terraces in the Carlin basin record the progressive downcutting into and removal of the middle Miocene sediments. Gravel deposits form a thin veneer on some of the higher terraces. Clasts in those gravel deposits, as well as the overall terrace pattern, indicate southward drainage towards the Humboldt River. The erosion gradually re-exposed the flanks of the surrounding highlands. A brief pause in downcutting allowed the formation of a small lake in the Hemphillian (late Miocene), represented by lacustrine units northwest of Carlin. The sedimentary rocks of the Carlin basin conceal a large segment of the world-class, late Eocene Carlin gold trend, which extends from the southern Independence Mountains south into the Piñon Range. Sedimentation largely buried the Gold Quarry and Mike gold deposits in the northwestern part of the basin. Later faulting and erosion re-exposed the Gold Quarry deposit, but the Mike deposit remains buried. The basin’s sedimentary units conceal potential Paleozoic host rocks, and the sedimentary facies and post-sedimentation faults shown on the map may help guide interpretations of geophysical and other exploration data in the Carlin basin. The current map publication was supported by the USGS National Cooperative Geologic Mapping Program under STATEMAP award number G19AC00383.

Nevada↗

USGS1999

Digital mining claim density map for federal lands in Nevada: 1996

This report describes a digital map generated by the U.S. Geological Survey (USGS) to provide digital spatial mining claim density information for federal lands in Nevada as of March 1997. Mining claim data is earth science information deemed to be relevant to the assessment of historic, current, and future ecological, economic, and social systems. There is no paper map included in this Open-File report. In accordance with the Federal Land Policy and Management Act of 1976 (FLPMA), all unpatented mining claims, mill, and tunnel sites must be recorded at the appropriate Bureau of Land Management (BLM) State office. BLM maintains a cumulative computer listing of mining claims in the MCRS database with locations given by meridian, township, range, and section. A mining claim is considered closed when the claim is relinquished or a formal BLM decision declaring the mining claim null and void has been issued and the appeal period has expired. All other mining claims filed with BLM are considered to be open and actively held. The digital map (figure 1.) with the mining claim density database available in this report are suitable for geographic information system (GIS)-based regional assessments at a scale of 1:100,000 or smaller.

Nevada↗

USGS2009

Mineral-resource assessment of northern Nye County, Nevada— A progress report

The U.S. Geological Survey (USGS), University of Nevada, Las Vegas (UNLV), and Nevada Bureau of Mines and Geology (NBMG), which is a part of the University of Nevada, Reno (UNR), have completed the first year of data collection and analysis in preparation for a new mineral- and energy-resource assessment of northern Nye County, Nevada. This report provides information about work completed before October 1, 2009. Existing data are being compiled, including geology, geochemistry, geophysics, and mineral-deposit information. Field studies are underway, which are primarily designed to address issues raised during the review of existing information. In addition, new geochemical studies are in progress, including reanalyzing existing stream-sediment samples with modern methods, and analyzing metalliferous black shales.

Nevada↗

USGS1982

Determination of in situ state of stress at the Spent Fuel Test-Climax site, Climax Stock, Nevada Test Site

Determination of the in situ state of stress at the site of the Spent Fuel Test--Climax, using the U.S. Bureau of Mines overcore method, indicates principal stress magnitudes of 11.6 MPa, 7.1 MPa, and 2.8 MPa. The bearing and plunge of the maximum and minimum principal stress components are, respectively: N. 56? E., 29? NE; and N. 42? W., 14? NW. The vertical stress magnitude of 7.9 MPa calculated from the overcore data is significantly less than expected from overburden pressure, suggesting the stress field is influenced by local or areal geologic factors. Results from this investigation indicate (1) the stress state at the Spent Fuel Test--Climax site deviates significantly from a gravitational stress field, both in relative stress magnitudes and in orientation; (2) numerical modeling will not realistically simulate the near-field response of the Spent Fuel Test--Climax site if gravitational and (or) horizontal and vertical applied stress boundary conditions are assumed; and (3) substantial stress variations may occur spatially within the stock.

Open-File Report↗

USGS1978

Mineral resources of the Charles Sheldon wilderness study area, Humboldt and Washoe Counties, Nevada, and Lake and Harney Counties, Oregon

A mineral survey of the Charles Sheldon wilderness study area, located in Humboldt and Washoe Counties, Nevada, and Lake and Harney Counties, Oregon was conducted in 1974 and 1975 (fig. 1A, 1B, 1C). The mineral resource potential was evaluated by geological, geochemical, and geophysical studies by the U.S. Geological Survey, and by the examination of mines, prospects, and other mineralized localities by the U.S. Bureau of Mines. The investigation identified several areas of significant mineral potential within the study area which includes the Charles Sheldon Antelope Range and the Sheldon National Antelope Refuge (fig. 1B). The Virgin Valley area contains reserves of precious opal, small quantities of decorative building stone, and low-grade uranium resources. The investigation indicates that there are several areas of potential for the discovery at depth of mercury and for base and complex precious metal sulfide deposits within the study area. Reservoir temperatures, estimated from the analysis of thermal springs, suggest that the area has low-to-moderate potential for geothermal resources. The potential for oil, gas, or coal is very low.

Nevada, Oregon↗

USGS1998

MAS/MILS Arc/Info point coverage for the western U.S. (excluding Hawaii)

The U.S. Geological Survey has two international and one regional digital database that contains information on mineral properties. This report describes the conversion of selected data from one of the international databases - MAS/MILS (Mineral Availability System/Mineral Industry Location System) - into a spatial data product. The MAS/MILS database, obtained from the U.S. Bureau of Mines (USBM) upon its closure, contains over 221,000 records of mineral properties and processing facilities throughout the world. However, the majority of the records in the database are of sites located in the western U.S. This is due to the extensive mineral activity that has occurred in the West, and the work done by mineral professionals in the Western, Alaska, and Intermountain Field Operations Centers of the USBM. The purpose of this project was to create a spatial coverage of the western U.S. containing mineral resource information. This coverage includes information for the states of Alaska, Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, and Wyoming. For this report, locations from MAS/MILS were converted to a point coverage using a geographic information system (GIS). All work was done using Arc/Info v. 7.0.4. There are 128,441 points in the coverage.

Alaska, Arizona, California, Colorado, Idaho, Mont↗

USGS2005

Geochemical Analyses of Geologic Materials from Areas of Critical Environmental Concern, Clark and Nye Counties, Nevada

INTRODUCTION An assessment of known and undiscovered mineral resources of selected areas administered by the Bureau of Land Management (BLM) in Clark and Nye Counties, Nevada was conducted by the U.S. Geological Survey (USGS), Nevada Bureau of Mines and Geology (NBMG), and University of Nevada, Las Vegas (UNLV). The purpose of this work was to provide the BLM with information for use in their long-term planning process in southern Nevada so that they can make better-informed decisions. The results of the assessment are in Ludington (2006). Existing information about the areas, including geology, geophysics, geochemistry, and mineral-deposit information was compiled, and field examinations of selected areas and mineral occurrences was conducted. This information was used to determine the geologic setting, metallogenic characteristics, and mineral potential of the areas. Twenty-five Areas of Critical Environmental Concern (ACECs) were identified by BLM as the object of this study. They range from tiny (less than one km2) to large (more than 1,000 km2). The location of the study areas is shown on Figure 1. This report includes geochemical data for rock samples collected by staff of the USGS and NBMG in these ACECs and nearby areas. Samples have been analyzed from the Big Dune, Ash Meadows, Arden, Desert Tortoise Conservation Center, Coyote Springs Valley, Mormon Mesa, Virgin Mountains, Gold Butte A and B, Whitney Pockets, Rainbow Gardens, River Mountains, and Piute-Eldorado Valley ACECs.

Open-File Report↗

USGS1979

Mineral resources of the Minarets Wilderness and adjacent areas, Madera and Mono counties, California

A mineral survey of the Minarets Wilderness area and adjacent areas in the central Sierra Nevada, Calif., was conducted during 1973 through 1975. The total area covers about 620 km 2 (237 sq mi) in the Sierra and Inyo National Forests, of which about 440 km 2 (170 sq mi) are within the officially designated Minarets Wilderness. The mineral resource potential was evaluated by geological, geochemical, and geophysical studies by the U.S. Geological Survey, and by examination of mineralized rocks, prospects, and mining claims by the U.S. Bureau of Mines. The results of the survey indicate that the study area has small to moderate submarginal to paramarginal resources of copper, silver, zinc, lead, iron, and tungsten and an unevaluated potential for molybdenum resources. Limestone is present, but not of commercial quantity or quality. No other industrial minerals have been recognized in quantity. Granitic rocks have potential use as decorative stone and sand and gravel could be produced from either alluvial deposits or glacial drift. However, these commodities are more accessible elsewhere at localities closer to markets. The study area has no potential for fossil fuels, and, because of the general geologic environment, the potential for nuclear fuel minerals is considered to be low. The study area has low geothermal potential, even though it is on the western edge of the Mono-Long Valley "Known Geothermal Resource Area" (KGRA). The area is underlain by metavolcanic and metasedimentary rocks that have been intruded by granitic rocks of the Sierra Nevada batholith. Pliocene volcanic rocks are present locally. With few exceptions, the known occurrences of mineralized rock are confined to the metamorphic rocks, and the exceptions appear to be confined to plutonic rocks that are older than the Late Cretaceous granitic rocks that make up the bulk of the batholithic rocks in the study area. Although no mineral production has been recorded from prospects within the study area, mines adjacent to it have produced significant amounts of gold and tungsten. Production figures are incomplete, but mines in the Mammoth mining district (fig. 1) may have produced as much as $1 million worth of gold, silver, and other metals at the then-existing prices. The Monte Cristo mine in the Mammoth district was in production during 1978.

California↗

USGS1996

Resource assessment of the Bureau of Land Management's Winnemucca District and Surprise Resource Area, Northwest Nevada and Northeast California; geology and its relation to resource genesis

The U.S. Geological Survey (USGS) is a party to joint interagency Memorandum of Understandings (MOUs) with the Bureau of Land Management (BLM) and the U.S. Bureau of Mines (USBM) to coordinate resource assessments and evaluations of BLM administered lands. Resource assessments of BLM Resource Areas, that are conducted by the USGS under these MOUs, assist the BLM in meeting inventory and evaluation, resource-management planning, and other management requirements of the Federal Land Policy and Management Act of 1976 (FLPMA). This report is one of several to be generated as part of a resource assessment of BLMadministered lands in northwest Nevada and northeast California. The project area is composed of three contiguous BLM Resource Areas (RAs), totalling 13.5 million acres, in northwest Nevada and northeast California (figs. 1, 2). The SonomaGerlach and Paradise-Denio Resource Areas in northwest Nevada together comprise the BLM's Winnemucca District. The Surprise RA is located in extreme northwest Nevada and northeast California and is part of the BLM's Susanville District, which is administered by the BLM's California state office. Henceforth in this report, the project area will be referred to as the Winnemucca-Surprise Resource Assessment Area (WSRAA). Sources of geologic data used in this compilation include the state geologic maps of Nevada (Stewart and Carlson, 1978) and California (Jennings, 1977). Other regional, largerscale geologic maps of the area that were used include the 1:250,000 scale Nevada county geologic maps (Willden, 1964; Bonham, 1969; Willden and Speed, 1974; Johnson, 1977), l:125,000-scale geologic quadrangle maps (Ferguson and others, 1951, 1952; Muller and others, 1951), 1:62,500-scale geologic quadrangle maps (Gilluly, 1967; Silberling and Wallace, 1967; Wallace and others, 1969a, b) and several 1:48,000- and 1:24,000-scale geologic quadrangle maps (e.g., Erickson and Marsh, 1974 b, c; Vikre, 1985b; Theodore, 1991 a, b; 1994; Doebrich, 1994, 1995; Jones, in press a, b). The geology of the WSRAA records a complex history of Paleozoic and Mesozoic accretionary and plutonic events followed by Tertiary extensional tectonism and magmatism. This report chronologically outlines sedimentologic, magmatic, and tectonic events that shaped the geology of the WSRAA and relates these events to the genesis and distribution of the region's mineral and non-mineral resources. This is the initial report of several scheduled to be prepared on the WSRAA. Others reports include geochemistry, geophysics, hydrothermal alteration classification using Landsat Thematic Mapper imagery, assessment of metallic mineral resources, assessment of non-metallic mineral resources, and assessment of oil and gas resources.

Open-File Report↗

USGS2000

Mercury bioaccumulation in fish in a region affected by historic gold mining: The South Yuba River, Deer Creek, and Bear River watersheds, California, 1999

Mercury that was used historically for gold recovery in mining areas of the Sierra Nevada continues to enter local and downstream water bodies, including the Sacramento Delta and the San Francisco Bay of northern California. Methylmercury is of particular concern because it is the most prevalent form of mercury in fish and is a potent neurotoxin that bioaccumulates at successive trophic levels within food webs. In April 1999, the U.S. Geological Survey, in cooperation with several other agencies the Forest Service (U.S. Department of Agriculture), the Bureau of Land Management, the U.S. Environmental Protection Agency, the California State Water Resources Control Board, and the Nevada County Resource Conservation District began a pilot investigation to characterize the occurrence and distribution of mercury in water, sediment, and biota in the South Yuba River, Deer Creek, and Bear River watersheds of California. Biological samples consisted of semi-aquatic and aquatic insects, amphibians, bird eggs, and fish. Fish were collected from 5 reservoirs and 14 stream sites during August through October 1999 to assess the distribution of mercury in these watersheds. Fish that were collected from reservoirs included top trophic level predators (black basses, Micropterus spp.) intermediate trophic level predators [sunfish (blue gill, Lepomis macrochirus; green sunfish, Lepomis cyanellus; and black crappie, Poxomis nigromaculatus)] and benthic omnivores (channel catfish, Ictularus punctatus). At stream sites, the species collected were upper trophic level salmonids (brown trout, Salmo trutta) and upper-to-intermediate trophic level salmonids (rainbow trout, Oncorhynchus mykiss). Boneless and skinless fillet portions from 161 fish were analyzed for total mercury; 131 samples were individual fish, and the remaining 30 fish were combined into 10 composite samples of three fish each of the same species and size class. Mercury concentrations in samples of black basses (Micropterus spp.), including largemouth, smallmouth, and spotted bass, ranged from 0.20 to 1.5 parts per million (ppm), wet basis. Mercury concentrations in sunfish ranged from less than 0.10 to 0.41 ppm (wet). Channel catfish had mercury concentrations from 0.16 to 0.75 ppm (wet). The range of mercury concentrations observed in rainbow trout was from 0.06 to 0.38 ppm (wet), and in brown trout was from 0.02 to 0.43 ppm (wet). Mercury concentrations in trout were greater than 0.3 ppm in samples from three of 14 stream sites. Mercury at elevated concentrations may pose a health risk to piscivorous wildlife and to humans who eat fish on a regular basis. Data presented in this report may be useful to local, state, and federal agencies responsible for assessing the potential risks associated with elevated levels of mercury in fish in the South Yuba River, Deer Creek, and Bear River watersheds.

California↗