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

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At least 379 records · Page 21Linked to original sources
USGS1983

Mineral resource potential map of the Selway-Bitterroot Wilderness, Idaho County, Idaho, and Missoula and Ravalli counties, Montana

Mineral resource studies by the U.S. Bureau of Mines and the U.S, Geological Survey indicate that five areas within the Selway-Bitterroot Wilderness have mineral resource potential. Regional studies suggest that three granitic plutons within the wildemess, the Running Creek pluton on the southwestern border of the wildemess, the Painted Rocks pluton on the southern border of the wildemess, and the Whistling Pig pluton in the west-central portion of the wildemess, have low potential for molybdenite deposits, but detailed surface investigations failed to recognize a deposit. Placer deposits in the Elk Summit area on the north side of the wildemess contain subeconomic resources of niobium- (columbium-) bearing ilmenite. A vein on the northeast side of the wildemess at t~e Cliff mine at Saint Joseph Peak contains subeconomic silver-copper-lead resources. The wilderness has no known potential for oil and gas, coal, geothermal resources, or other energy-related commodities.

Idaho, Montana↗
USGS2002

Dissolved cadmium, zinc, and lead loads from ground-water seepage into the South Fork Coeur d'Alene River system, northern Idaho, 1999

The valley of the South Fork Coeur d’Alene River and some of its tributaries have been heavily impacted by the dispersion of metal-enriched materials from the Coeur d’Alene mining district since 1884. The valley floor, including the unconsolidated valley-fill/flood-plain aquifers, is a major holding area for mine tailings. The U.S. Geological Survey, in cooperation with the U.S. Environmental Protection Agency, characterized groundwater and surface-water relations for parts of the South Fork Coeur d’Alene River Basin and quantified the loading of dissolved metals into the South Fork Coeur d’Alene River system from groundwater seepage. This information can be used to determine the effects of dissolved metal from ground-water seepage on the river system and to evaluate the necessity and feasibility of remediation along gaining reaches. This study defines a field approach that can be repeated during and after the implementation of remediation solutions to measure the effectiveness of these efforts in reducing loading to streams. The study area includes three reaches along the South Fork Coeur d’Alene River valley in the Coeur d’Alene mining district in central Shoshone County, northern Idaho: a 3.3-mile reach of Canyon Creek at Woodland Park, a 4.8-mile reach of the South Fork Coeur d’Alene River near Osburn, and a 6.5-mile reach of the South Fork Coeur d’Alene River near Kellogg and Smelterville. Seepage studies were conducted during July 27–29; September 17–19; and October 15–17, 1999. Each seepage study was conducted over a 3-day period, during which each station was measured on a daily basis for streamflow, and waterquality samples were collected. The consecutiveday approach allowed for an evaluation of variability in streamflow gains and losses and metal loading that resulted from changing hydrologic conditions. During the July, September, and October seepage studies, ground-water seepage was the predominant source for gains in dissolved cadmium and zinc loads in the three study reaches, whereas tributary inflow loads were a minor source. The overall average net gain in dissolved zinc load from ground-water seepage into the South Fork Coeur d’Alene River near Kellogg and Smelterville was about 730 pounds per day, compared with the net gains in Canyon Creek at Woodland Park and the South Fork Coeur d’Alene River near Osburn, which were roughly similar at 150 and 218 pounds per day, respectively. The net gain in dissolved cadmium load from ground-water seepage into the three river reaches was about two orders of magnitude less than the gain in dissolved zinc. On the South Fork Coeur d’Alene River study reaches near Osburn and near Kellogg and Smelterville, no pattern associated with an increase or decrease in dissolved lead load along gaining or losing subreaches was recognizable. Canyon Creek at Woodland Park was the only study reach where ground-water seepage contributed appreciably to the dissolved lead load; the average net gain was 1.5 pounds per day. The average dissolved lead loads leaving South Fork Coeur d’Alene River study reaches (corrected for tributary inflow along the study reaches) near Osburn and near Kellogg and Smelterville were 1.4 and 0.8 pounds per day less, respectively, than the loads entering the study reaches. The decrease in dissolved lead could be the result of lead adsorbing onto organic and inorganic sediment surfaces and (or) coprecipitating with iron and manganese oxides. These forms of lead likely will be resuspended into the water column at high flows.

Idaho↗
USGS2017

Geologic map of the Bateman Spring Quadrangle, Lander County, Nevada

This 1:24,000-scale geologic map of the Bateman Spring 7.5-minute quadrangle in Lander County, Nevada contains descriptions of 24 geologic units and one cross section. Accompanying text includes full unit descriptions and references. This quadrangle includes lower Paleozoic siliciclastic sedimentary rocks of the Roberts Mountain allochthon, Miocene intrusive dikes, alluvial deposits of the northern Shoshone Range piedmont, and riverine deposits of the Reese and Humboldt rivers. Significant findings include: refined age estimates for the Ordovician-Cambrian Valmy Formation and Devonian Slaven Chert, based on new fossil information; and detailed mapping of late Quaternary fault traces along the Shoshone Range fault system.

Nevada Bureau of Mines and Geology Map↗
USGS1999

Preliminary geologic map of the Chugach National Forest special study area, Alaska

In 1990, both the U.S. Geological Survey and U.S. Bureau of Mines were contacted by the Chugach National Forest (CNF) for the purpose of providing mineral resource information for the CNF Master Plan during the planning period fiscal years 1991-1994. This information is to address the terms and requirements of the 1986 Settlement Agreement and to provide mineral and geologic information useful to the CNF for making land-use decisions. In early 1992 an Interagency Agreement between the U.S. Geological Survey, the U.S. Bureau of Mines and the Chugach National Forest was signed. In this agreement the U.S. Geological Survey is to provide a report which estimates the undiscovered mineral endowments of the 'special' study area and to identify the potential for mineral discovery and development. The U.S. Bureau of Mines was to prepare a report updating the discovered mineral endowment of the Special Study Area. These reports are now published (Roe and Balen, 1994; Nelson and others, 1994). This geologic map is a component of the U.S. Geological Survey contribution to the overall project.

Alaska↗
USGS2006

Environmental effects of historical mining in the Boulder River watershed, southwestern Montana

The U.S. Geological Survey recently completed an environmental study of historical mining in the Boulder River watershed, Montana, using the watershed approach. Results of the study have been used by State and Federal agencies to plan and implement cleanup. The watershed approach is based on the premise that contaminated sites that have the most profound effect on water and ecosystem quality within an entire watershed can be identified, characterized, and ranked for cleanup.

Fact Sheet↗
USGS2022

Geologic map of the Silver Zone Pass quadrangle, Elko County, Nevada

This 1:24,000-scale geologic map of the Silver Zone Pass quadrangle lies in the southern Toano Range in Elko County, Nevada. Metamorphic and sedimentary strata of the quadrangle range from Neoproterozoic to Permian in age. Important intrusions include the Late Jurassic (ca. 159 Ma) Silver Zone Pass pluton and Cretaceous Toano Spring pluton. In particular, the Silver Zone Pass pluton involves undeformed dikes that crosscut metamorphic foliations and the pluton is associated with pluton-margin anticlines. Interpretation of these characteristics suggests that the pluton was syn-kinematic with respect to metamorphism and strain, thus requiring a phase of Late Jurassic deformation. A Miocene rhyolite lava is of particular interest as one of the few topaz-bearing volcanic rocks in Nevada. A major detachment fault places non-metamorphosed Paleozoic rocks over low-grade Paleozoic and Proterozoic rocks. High-angle normal faults tilted the range in several blocks, and Miocene Humboldt Formation were deposited on, and faulted against, bedrock. Rocks of the Toano Range are bounded by broad valleys on the east and west, with the eastern basin being at much lower elevation than the western basin. Pleistocene lakes, which created distinctive beach deposits, occupied both basins, with Lake Bonneville on the east and Lake Waring on the west. Silver Zone Pass owes its low relief to the enhanced weathering and erosion of the rock within the pass, a granodiorite pluton. The weathering has created some unusual landforms such as tors.

Nevada↗
USGS2011

Global Positioning System constraints on crustal deformation before and during the 21 February 2008 Wells, Nevada M6.0 earthquake

Using Global Positioning System (GPS) data from permanent sites and U.S. Geological Survey (USGS) campaign data we have estimated co-seismic displacements and secular background crustal deformation patterns associated with the 21 February 2008 Wells Nevada earthquake. Estimated displacements at nearby permanent GPS sites ELKO (84 km distant) and GOSH (81 km distant) are 1.0±0.2 mm and 1.1±0.3 mm, respectively. The magnitude and direction are in agreement with those predicted from a rupture model based on InSAR measurements of the near-field co-seismic surface displacement. Analysis of long GPS time series (>10 years) from the permanent sites within 250 km of the epicenter indicate the eastern Nevada Basin and Range undergoes steady tectonic transtension with rates on the order of 1 mm/year over approximately 250 km. The azimuth of maximum horizontal crustal extension is consistent with the azimuth of the Wells earthquake co-seismic slip vector. The orientation of crustal shear is consistent with deformation associated with Pacific/North America plate boundary relative motion seen elsewhere in the Basin and Range. In response to the event, we deployed a new GPS site with the capability to telemeter high rate, low latency data that will in the future allow for rapid estimation of surface displacement should aftershocks or postseismic deformations occur. We estimated co-seismic displacements using campaign GPS data collected before and after the event, however in most cases their uncertainties were larger than the offsets. Better precision in co-seismic displacement could have been achieved for the campaign sites if they had been surveyed more times or over a longer interval to better estimate their pre-event velocity.

Nevada↗
USGS1989

Analysis of exceptionally large tremors in two gold mining districts of South Africa

An investigation of ground motion, recorded using broad-band, wide dynamic-range digital seismographs, of large mine tremors from two South African mining districts with different geologic settings, reveals some essential differences in both seismic source and ground motion parameters. In the Klerksdorp district where the strata are offset by major throughgoing normal faults, the largest tremors, with magnitudes ranging as high as 5.2, tend to be associated with slip on these pre-existing faults. Moreover, the seismic source and ground motion parameters are quite similar to those of natural crustal earthquakes. In the Carletonville district, by contrast, where substantial faults do not exist, the large-magnitude tremors appear to result from the failure of relatively intact rock and cause seismic stress drops and ground motion parameters higher than normally observed for natural shocks. Additionally, there appears to be an upper magnitude limit of about 4 in the Carletonville district. Detailed analyses of an exceptionally large event recorded locally from each of these districts serve to highlight these contrasts. ?? 1989 Birkha??user Verlag.

Pure and Applied Geophysics PAGEOPH↗
USGS1993

Summary of the mineral- and energy-resource endowment, BLM roswell resource area, east-central New Mexico

In this summary of two comprehensive resource reports produced by the U.S. Bureau of Mines and the U.S. Geological Survey for the U.S. Bureau of Land Management, we discuss the mineral- and energyresource endowment of the 14-millon-acre Roswell Resource Area, New Mexico, managed by the Bureau of Land Management. The Bureau and Survey reports result from separate studies that are compilations of published and unpublished data and integrate new findings on the geology, geochemistry, geophysics, mineral, industrial, and energy commodities, and resources for the seven-county area. The reports have been used by the Bureau of Land Management in preparation of the Roswell Resource Area Resource Management Plan, and will have future use in nationwide mineral- and energy-resource inventories and assessments, as reference and training documents, and as public-information tools. In the Roswell Resource Area, many metals, industrial mineral commodities, and energy resources are being, or have been, produced or prospected. These include metals and high-technology materials, such as copper, gold, silver, thorium, uranium and/or vanadium, rare-earth element minerals, iron, manganese, tungsten, lead, zinc, and molybdenum; industrial mineral resources, including barite, limestone/dolomite, caliche, clay, fluorspar, gypsum, scoria, aggregate, and sand and gravel; and fuels and associated resources, such as oil, gas, tar sand and heavy oil, coal, and gases associated with hydrocarbons. Other commodities that have yet to be identified in economic concentrations include potash, halite, polyhalite, anhydrite, sulfur, feldspar, building stone and decorative rock, brines, various gases associated with oil and gas exploration, and carbon dioxide. ?? 1993 Oxford University Press.

Nonrenewable Resources↗
USGS2008

Geology and geochemistry of the Mammoth breccia pipe, Copper Creek mining district, southeastern Arizona: Evidence for a magmatic-hydrothermal origin

The Copper Creek mining district, southeastern Arizona, contains more than 500 mineralized breccia pipes, buried porphyry-style, copper-bearing stockworks, and distal lead-silver veins. The breccia pipes are hosted by the Copper Creek Granodiorite and the Glory Hole volcanic rocks. The unexposed Mammoth breccia pipe, solely recognized by drilling, has a vertical extent of 800 m and a maximum width of 180 m. The pipe consists of angular clasts of granodiorite cemented by quartz, chalcopyrite, bornite, anhydrite, and calcite. Biotite 40Ar/ 39Ar dates suggest a minimum age of 61.5??0.7 Ma for the host Copper Creek Granodiorite and 40Ar/39Ar dates on hydrothermal sericite indicate an age of 61.0??0.5 Ma for copper mineralization. Fluid inclusion studies suggest that a supercritical fluid with a salinity of approximately 10 wt.% NaCl equiv. condensed to a dilute aqueous vapor (1-2.8 wt.% NaCl equiv.) and a hypersaline brine (33.4-35.1 wt.% NaCl equiv.). Minimum trapping temperatures are 375??C and trapping depths are estimated at 2 km. Sulfur isotope fractionation of cogenetic anhydrite and chalcopyrite yields a temperature of mineralization of 469??25??C. Calculated oxygen and hydrogen isotope values for fluids in equilibrium with quartz and sericite range from 10.2??? to 13.4??? and -60??? to -39???, respectively, suggesting that the mineralizing fluid was dominantly magmatic. Evidence from the stable isotope and fluid inclusion analyses suggests that the fluids responsible for Cu mineralization within the Mammoth breccia pipe exsolved from a gray porphyry phase found at the base of the breccia pipe. ?? Springer-Verlag 2008.

Mineralium Deposita↗
USGS1999

Petrology and geochemistry of late-stage intrusions of the A-type, mid-Proterozoic Pikes Peak batholith (Central Colorado, USA): Implications for petrogenetic models

The ~1.08 Ga anorogenic, A-type Pikes Peak batholith (Front Range, central Colorado) is dominated by coarse-grained, biotite ?? amphibole syenogranites and minor monzogranites, collectively referred to as Pikes Peak granite (PPG). The batholith is also host to numerous small, late-stage plutons that have been subdivided into two groups (e.g. Wobus, 1976. Studies in Colorado Field Geology, Colorado School of Mines Professional Contributions, Colorado): (1) a sodic series (SiO2= ~44-78 wt%; K/Na=0.32-1.36) composed of gabbro, diabase, syenite/quartz syenite and fayalite and sodic amphibole granite; and (2) a potassic series (SiO2= ~ 70-77 wt%; K/Na=0.95-2.05), composed of biotite granite and minor quartz monzonite. Differences in major and trace element and Nd isotopic characteristics for the two series indicate different petrogenetic histories. Potassic granites of the late-stage intrusions appear to represent crustal anatectic melts derived from tonalite sources, based on comparison of their major element compositions with experimental melt products. In addition, Nd isotopic characteristics of the potassic granites [??(Nd)(1.08 Ga) = -0.2 to -2.7] overlap with those for tonalites/granodiorites [ca 1.7 Ga Boulder Creek intrusions; ??(Nd)(1.08 Ga) = -2.4 to -3.6] exposed in the region. Some of the partial melts evolved by fractionation dominated by feldspar. The late-stage potassic granites share geochemical characteristics with most of the PPG, which is also interpreted to have an anatectic origin involving tonalitic crust. The origin of monzogranites associated with the PPG remains unclear, but mixing between granitic and mafic or intermediate magmas is a possibility. Syenites and granites of the sodic series cannot be explained as crustal melts, but are interpreted as fractionation products of mantle-derived mafic magmas with minor crustal input. High temperature and low oxygen fugacity estimates (e.g. Frost et al., 1988. American Mineralogist 73, 727-740) support a basalt fractionation origin, as do ??(Nd) values for sodic granitoids [??(Nd)(1.08 Ga) = +2.2 to -0.7], which are higher than ??(Nd) values for Colorado crust at 1.08 Ga (ca -1.0 to -4.0). Enrichments in incompatible elements (e.g. rare earth elements, Rb, Y) and depletions in compatible elements (e.g. Cr, Sr, Ba) in the sodic granitoids compared to coeval mafic rocks are also consistent with fractionation. Accessory mineral fractionation, release of fluorine-rich volatiles and/or removal of pegmatitic fluids could have modified abundances of Ce, Nb, Zr and Y in some sodic granitoid magmas. Gabbros and mafic dikes associated with the sodic granitoids have ??(Nd)(1.08 Ga) of -3.0 to +3.5, which are lower than depleted mantle at 1.08 Ga, and their trace element characteristics suggest derivation from mantle sources that were previously affected by subduction-related processes. However, it is difficult to characterize the mantle component in these magmas, because assimilation of crust during magma ascent could also result in their observed geochemical features. The Pikes Peak batholith is composed of at least two petrogenetically different granite types, both of which exhibit geochemical characteristics typical of A-type granites. Models proposed for the petrogenesis of the granitoids imply the existence of mafic rocks at depth and addition of juvenile material to the crust in central Colorado at ~ 1.1 Ga.

Precambrian Research↗
USGS2024

The influence of anthropogenic regulation and evaporite dissolution on earthquake-triggered ground failure

Remote sensing observations of Searles Lake following the 2019 moment magnitude 7.1 Ridgecrest, California, earthquake reveal an area where surface ejecta is arranged in a repeating hexagonal pattern that is collocated with a solution-mining operation. By analyzing geologic and geotechnical data, here we show that the hexagonal surface ejecta is likely not a result of liquefaction. Instead, we propose dissolution cavity collapse (DCC) as an alternative driving mechanism. We support this theory with pre-event Interferometric Synthetic Aperture Radar data, which reveals differential subsidence patterns and the creation of subsurface void space. We also find that DCC is likely triggered at a lower shaking threshold than classical liquefaction. This and other unknown mechanisms can masquerade as liquefaction, introducing bias into liquefaction prediction models that rely on liquefaction inventories. This paper also highlights the opportunities and drawbacks of using remote sensing data to disentangle the complex factors that influence earthquake-triggered ground failure.

California↗
USGS1998

Carolina slate belt gold deposits in Virginia, North Carolina, South Carolina, and Georgia

The Southeastern United States, in particular, the Carolina slate belt of Virginia, North Carolina, South Carolina, and Georgia, has been an important region of mineral production (fig. 1). This region is thought to have major potential for containing large undiscovered deposits of gold and silver, as well as copper, lead, zinc, molybdenum, and tin. Gold production from the major mines (Haile, Brewer, Ridgeway, and Barite Hill) in South Carolina ranked sixth in the Nation in 1992. Despite the closing of all but one mine in 1997, the region continues to attract intense scrutiny by the mining industry. Current U.S. Geological Survey (USGS) efforts in the slate belt are led by a multidisciplinary team focused on an integrated, multistate, and multiyear project that has the potential to result in a fundamental reinterpretation of the economic geology of the region. The slate belt is considered a scientific frontier because of the rapid pace of data acquisition by the USGS, academia, and private sector geologists and because emerging concepts of its geologic evolution are controversial. Establishing the origin of the gold deposits is important, not only in guiding exploration, but for more accurate assessment of the potential for the occurrence of new deposits throughout the southern Appalachians. These efforts may result in further industry exploration that may lead to discovery of new economically viable mineral deposits, which would have a broad economic impact on the region. Another goal is to find ways to prevent human activities related to gold extraction from remobilizing toxic metals found in these deposits, which could have potential harmful effects on the environment.

Georgia, North Carolina, South Carolina, Virginia↗
USGS1992

Geology and mineral paragenesis of the Pea Ridge iron ore mine, Washington County, Missouri: Origin of the rare-earth-element- and gold-bearing breccia pipes. Some mineralogical and geochemical aspects of middle and upper Pennsylvanian marine black shales in part of the midcontinent region. Mineralogical and geochemical analysis of the metal- and organic-rich Grassy Creek Shale of the New Albany group (Upper Devonian and Lower Mississippian) in Hardin County, southern Illinois

No abstract available.

Illinois, Iowa, Kansas, Missouri, Nebraska, Oklaho↗
USGS1955

Coal reserves of the Pittsburgh (No. 8) bed in Belmont County, Ohio

Remaining coal reserves totaling 1,929 million tons have been appraised in the Pittsburgh (No. 8) coal bed in Belmont County, Ohio. Of these, 508 million tons are classified as measured and 1,421 million tons are classified as indicated. All the coal has less than 1,000 feet of overburden, and most of it is of high volatile A bituminous rank. This estimate is based on field work by the United States Geological Survey, supplemented by data from the fries of the Ohio Geological Survey and from mine and drill-hole records provided by mining companies.

Ohio↗
USGS2024

Contaminant exposure framework—Havasupai perspective

The conceptual risk framework, previously developed by the U.S. Geological Survey, for uranium mining was updated to include indigenous knowledge components informed by the Havasupai Tribe perspective. This General Information Product was designed to show the contaminant exposure framework from the Havasupai perspective.

General Information Product↗
USGS2024

Conceptual risk framework—Havasupai perspective

The conceptual risk framework, previously developed by the U.S. Geological Survey, for uranium mining was updated to include indigenous knowledge components informed by the Havasupai Tribe perspective. This General Information Product was designed to show the contaminant risk framework from the Havasupai perspective.

General Information Product↗