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At least 1,117 records · Page 62Linked to original sources
USGS2008

USGS Research Helps the County of Los Angeles Address New Arsenic Standards

In January 2006, the U.S. Environmental Protection Agency (USEPA) enacted stringent standards on arsenic in drinking water. The new limitsraised concerns about wells in the Antelope Valley of northern Los Angeles County that had high levels of naturally occurring arsenic. To meet the new standard, Los Angeles County Waterworks District No. 40, part of the Los Angeles County Department of Public Works, considered building arsenic-removal facilities at a cost of nearly $34 million. Instead, the District initiated a well-modification project that was based on the findings of a U.S. Geological Survey (USGS) scientific investigation. Using a well flowmeter and down-hole sampler - invented by USGS scientists ? the study team found that high-arsenic levels were concen-trated in the deepest portions of the wells, 600 feet or more below the land surface. Using this finding, the District implemented a well modification pilot project where the deep portions of five wells were sealed off permanently, while preserving the ability to pump high-quality water from the upper sections. Well screens in the upper sections were first cleaned using an innovative sonic technique to increase the yield of high-quality water. The deeper sections then were sealed using micro-fine cement technology. The District now pumps water that meets the new USEPA standard for arsenic from the affected wells. Arsenic concentrations are lower by an average of 84 percent, while well yield is lower by only 24 percent. The total cost of the modification project for the five wells was $608,580; a one-time net savings of 550 percent over construction of an arsenic-removal facility.

Fact Sheet↗
USGS1992

Maps showing mineral resource assessment for skarn deposits of gold, silver, copper, tungsten, and iron in the Butte 1 degree by 2 degrees Quadrangle, Montana

The purpose of this report is to assess the potential for undiscovered skarn deposits of gold, silver, copper, tungsten, and iron in the Butte 1 °X2° quadrangle. Other deposit types have been assessed and reports for each of the following have been prepared: Vein and replacement deposits of gold, silver, copper, lead, zinc, ·manganese, and tungsten; porphyry-stockwork deposits of copper, molybdenum, and tungsten; stockwork-disseminated deposits of gold and silver; placer deposits of gold; and miscellaneous deposit types including strata-bound deposits of copper and silver in rocks of the Middle Proterozoic Belt Supergroup, phosphate deposits in the Permian Phosporia Formation, and deposits of barite and fluorite. The Butte quadrangle, in west-central Montana, is one of the most mineralized and productive mining regions in the U.S. Its mining districts, including the world famous Butte or Summit Valley district, have produced a variety of metallic and nonmetallic mineral commodities valued at more than $6.4 billion (at the time of production). Because of its importance as a mineral producing region, the Butte quadrangle was selected for study by the U.S. Geological Survey under the Conterminous United States Mineral Assessment Program (CUSMAP). Under this program, new data on geology, geochemistry, geophysics, geochronology, mineral resources, and remote sensing were collected and synthesized. The field and laboratory studies were supported, in part, by funding from the Geologic Framework and Synthesis Program and the Wilderness Program. The methods used in resource assessment include a compilation of all data into data sets, the development of an occurrence model for skarn deposits in the quadrangle, and the analysis of data using techniques provided by a Geographic Information System (GIS). This map is one of a number of reports and maps on the Butte 1 °X2° quadrangle. Other publications resulting from this study include U.S. Geological Survey (USGS) Miscellaneous Investigations Series Maps 1-2050-A (Rowan and Segal, 1989), 1-2050-B (Rowan and others, 1991), 1-2050-D (Elliott and others, in press); Miscellaneous Field Studies Map MF-1925 (Wallace, 1987a); and Open-File Reports OF-86-292 (Wallace and others, 1986) and OF-86-0632 (Elliott and others, 1986).

IMAP↗
USGS2001

Subsurface correlations and sequence stratigraphic interpretations of lower Silurian strata in the Appalachian Basin of northeast Ohio, southwest New York, and northwest Pennsylvania

Significant quantities of recoverable natural gas resources are estimated to be in the regionally extensive Lower Silurian Medina Group and “Clinton” sandstone of the Appalachian Basin (Gautier and others, 1995; Ryder and others, 1996; Ryder, 1998). In order to assess these accumulations of natural gas more accurately, the U.S. Geological Survey (USGS) has investigated the Silurian stratigraphy along six lines of cross section located in New York, Pennsylvania, Ohio, and West Virginia (fig. 1). Cross section A–A' extends about 375 mi from northeast to southwest and is oriented approximately parallel to the nearby paleoshoreline of the Silurian epeiric sea. The remaining cross sections extend about 100–200 mi from northwest to southeast and are oriented nearly perpendicular to the paleoshoreline. Stratigraphic investigations along A–A' were reported by Ryder (2000), correlations along D–D' were reported by Keighin (1998), and investigations along E–E' and F–F' were in progress at the time of this publication. This report provides correlations for Silurian strata along cross sections B–B' and C–C', which are located in the northern part of the Appalachian Basin (figs. 1 and 2). Cross section B–B' extends about 140 mi from Chautauqua County, N.Y., to Clinton County, Pa., and C–C' extends about 200 mi from Lake County, Ohio, to Clinton County, Pa. Correlations are made along B–B' and C–C' for the Lower Silurian Medina and Clinton Groups, Lower Silurian Tuscarora and Rose Hill Formations, and Lower and Upper Silurian Lockport Group and Mifflintown Formation (lower part). Emphasis is placed on the Medina Group because it is the principal natural gas reservoir in the Silurian deposit.

Ohio, Pennsylvania↗
USGS2003

Geologic Map of the Wilderness and Handy Quadrangles, Oregon, Carter, and Ripley Counties, Missouri

The bedrock exposed in the Wilderness and Handy Quadrangles, Missouri, comprises Early Ordovician aged dolomite, sandstone, and chert. The sedimentary rocks are nearly flat-lying except where they are adjacent to faults. The carbonate rocks are karstified and the area contains numerous sinkholes, springs, caves, and losing-streams. This map is one of several being produced under the U.S. Geological Survey National Cooperative Geologic Mapping Program to provide geologic data applicable to land-use problems in the Ozarks of south-central Missouri. Ongoing and potential industrial and agricultural development in the Ozarks region has presented issues of ground-water quality in karst areas. These quadrangles contain significant areas of the Mark Twain National Forest, including part of the Eleven Point National Scenic Riverway and the Irish Wilderness Roadless Area. A National Park in this region (Ozark National Scenic Riverways, Missouri ) is concerned about the effects of activities in areas outside of their stewardship on the water resources that define the heart of this Park. This task applies geologic mapping and karst investigations to address issues surrounding competing land use in south-central Missouri. For more information see: http://geology.er.usgs.gov/eespteam/Karst/index.html

IMAP↗
USGS1981

Maps showing mineral resource potential of the Virgin Mountains Instant Study Area, Clark County, Nevada

The Virgin Mountains Instant Study Area contains about 30,000 acres (12,000 ha) in southeastern Nevada. In accordance with the Federal Land Policy and Management Act (P.L. 94-579), the U.S. Bureau of Mines examined mines, prospects, and mineralized zones, and the U.S. Geological Survey made regional geologic, geophysical, and geochemical investigations. Tungsten and sheet mica have been produced from the study area, and oil and gas lease applications have been filed on 20,300 acres (8,200 ha). Sixteen mining claims are presently held.

Nevada↗
USGS1983

Mineral resource potential map of the Blanco Mountain and Black Canyon Roadless Areas, Inyo and Mono Counties, California

On the basis of geologic, geochemical, and geophysical investigations and a survey of mines and prospects, the mineral resource potential for gold, silver, lead, zinc, tungsten, and barite of the Blanco Mountain and Black Canyon Roadless Areas is judged to be low to moderate, except for one local area that has high potential for gold and tungsten resources. A geochemical survey detected moderately anomalous amounts of lead, copper, and zinc and less anomalous concentrations of tungsten, gold, and silver. Elements in anomalous samples were grouped as suites known to form in various ore deposits. Four element suites that may be indicative of mineralization are recognized in the White Mountains: (1) lead, zinc, and silver in carbonate rocks; (2) copper, barite, and lead in veins and replacement bodies; (3) tungsten, molybdenum, and bismuth in skarns; and (4) gold and arsenic in mineralized quartz veins. The assessment of the areas of resource potential was made in part by the application of ore deposit models to the geochemical results. A mineral deposit survey by the U.S. Bureau of Mines indicates that there are no properties with identified mineral resources in the Blanco Mountain Roadless Area. There is one active placer claim. In the Black Canyon Roadless Area, two properties have 40,000 tons of indicated and inferred low-grade gold, silver, or lead-bearing rock. Five properties near this roadless area have 150,000 tons of indicated and inferred low-grade gold, silver, lead, zinc, or tungsten-bearing rock. About 90 percent of this tonnage is estimated to occur at the Mirage-Mariposa and the Hope mines. The roadless areas have no known resource potential for geothermal energy, coal, oil, or gas.

California↗
USGS1982

Mineral resources potential map of the Lost Cove and Harper Creek Roadless Areas, Avery and Caldwell counties, North Carolina

A geologic, geophysical, and geochemical investigation and a survey of mines, quarries, and prospects have been conducted to evaluate the mineral resource potential of the Lost Cove and Harper Creek Roadless Areas, Avery and Caldwell Counties, North Carolina. The study area lies within the Blue Ridge physiographic province and is predominatly underlain by Precambrian age plutonic and metasedimentary rocks of low metamorphic grade. All surface and mineral rights are Federally owned. Permit areas for uranium prospecting cover about 85 percent of the area. Uranium-rich rock in the Lost Cove and Harper Creek Roadless Areas occurs widely in the Wilson Creek Gneiss and to a minor extent in the Grandfather Mountain Formation. Vein-type deposits and other occurrences of uranium in foliated rocks in the Wilson Creek Gneiss have uranium resource potential. Speculative resources of uranium in vein-type deposits and in supergene-enriched foliated rocks are estimated to total 4 to 8 million pounds of U 3 O 8 . Mineral resources having low to moderate potential are gold and minerals of thorium, beryllium, niobium, and copper. Stone has a low economic potential; lead, molybdenum, and titanium have low resource potential. These conclusions are based on results of prospect examination, radiometric survey, geochemical survey of stream sediments, saprolite, and bedrock.

North Carolina↗
USGS1983

Mineral resource potential map of the Sugarloaf Roadless Area, San Bernardino County, California

Geologic, geochemical, and geophysical investigations and a survey of mines and prospects indicate that the Sugaloaf Roadless Area contains subeconomic graphite and magnesian marble resources. Parts of the area have a low potential for the occurrence of additional low-grade graphite resources, but there is no potential for additional magnesian marble resources within the roadless area. Sand, gravel, and construction stone other than carbonate rocks are found in the roadless area, but similar or better quality materials are abundant and more accessible outside the area. The roadless area has no identified energy mineral resources, but parts of the area have a low to moderate potential for low-grade uranium resources. There are no identified metallic mineral resources within the area, and there is no evidence of a potential for the occurrence of such resources. No previously unknown mineral occurrence was located during this study.

California↗
USGS1989

Summary geochemical maps of the Harrison 1° x 2° quadrangle, Arkansas and Missouri

This map is the first in a folio of maps of the Harrison 1° x 2° quadrangle, Arkansas and Missouri, prepared under the Conterminous United States Mineral Assessment Program. Additional maps showing various other geologic aspects of the Harrison quadrangle will be published as U.S. Geological Survey Miscellaneous Field Studies Maps bearing the same serial number with different letter suffixes (MF-1994-B, -C, and so on). Geochemical studies of the Harrison lo x 2° quadrangle, Arkansas and Missouri, are part of a joint multidisciplinary study by the U.S. Geological Survey; the Division of Geology and Land Survey, Missouri Department of Natural Resources; and the Arkansas Geological Commission. The objective of the joint study is to assess the mineral-resource potential of the area by integrated geologic, geochemical, and geophysical investigations.

Arkansas, Missouri↗
USGS1972

Drift of surface and near-bottom waters of the San Francisco Bay system, California: March 1970 through April 1971

The San Francisco Bay system is a complex estuary in which there is an interplay between natural chemical and physical processes, and changes resulting from the works of man. The bay is used for recreation, water-borne commerce, fishing, domestic and industrial waste disposal, and esthetic pleasure. Because some of these uses are competitive, it is desirable to adequately predict the impact of man's activities on this natural system. The reliability of such predictions will be strengthened by long-term observations directed toward understanding the natural processes occurring in the bay. This study is a compilation of one aspect of the U.S. Geological Survey's continuing investigations of the San Francisco Bay system.

California↗
USGS2003

Four models used for numerical simulation of a borehole radar antenna

In this report are four different models that represent an antenna used by personnel at the U.S. Geological Survey for crosswell investigations. The four models vary in complexity and concomitantly the accuracy with which they represent the actual antenna. These models are used in numerical simulations of the antenna to determine how it radiates radar waves.

Open-File Report↗
USGS2008

Near-shore and off-shore habitat use by endangered juvenile Lost River and Shortnose Suckers in Upper Klamath Lake, Oregon: 2006 data summary

Lost River suckers Deltistes luxatus and shortnose suckers Chasmistes brevirostris , listed as endangered in 1988 under the Endangered Species Act, have shown infrequent recruitment into adult populations in Upper Klamath Lake (NRC 2004). In an effort to understand the causes behind and provide management solutions to apparent recruitment failure, a number of studies have been conducted including several on larval and juvenile sucker habitat use. Near-shore areas in Upper Klamath Lake with emergent vegetation, especially those near the mouth of the Williamson River, were identified as important habitat for larval suckers (Cooperman and Markle 2000; Reiser et al. 2001). Terwilliger et al. (2004) characterized primary age-0 sucker habitat as near-shore areas in the southern portion of Upper Klamath Lake with gravel and cobble substrates. Reiser et al. (2001) provided some evidence that juvenile suckers use habitats with emergent vegetation, but nothing concerning the extent or timing of use. The U.S. Geological Survey (USGS) began investigating the importance of near-shore and off-shore habitats with and without emergent vegetation for juvenile suckers in 2000. We found substantial numbers of juvenile suckers using these habitats near the mouth of the Williamson River into late August (VanderKooi and Buelow 2003). The distribution and relative abundance of juvenile suckers showed high spatial variability throughout the summer for all species combined, Lost River suckers, and shortnose suckers (VanderKooi et al. 2006; Hendrixson et al. 2007a). Results from sampling near-shore areas in 2002 suggested juvenile sucker proximity to shoreline changes depending on the presence or absence of shoreline vegetation (VanderKooi et al. 2006), whereas in 2004 and 2005 results were equivocal (Hendrixson et al. 2007a, 2007b). Research by USGS of juvenile suckers in Upper Klamath Lake conducted since 2000 provides a valuable long-term data set which can be used to evaluate multi-year trends in juvenile sucker relative abundance and habitat use. Data on the relative abundance of juvenile suckers and their habitat use patterns will provide valuable information to guide restoration and management decisions in the Upper Klamath Basin. Information on juvenile sucker catch rates may also be valuable for evaluating year class success, estimating early life stage survival rates, and predicting upper bounds of future recruitment to adult spawning populations. We continued sampling juvenile suckers in 2006 as part of an effort to develop bioenergetics models for juvenile Lost River and shortnose suckers. This study required us to collect fish to determine growth rates and energy content of juvenile suckers. We followed the sampling protocols and methods described by Hendrixson et al. (2007b) to maintain continuity and facilitate comparisons with data collected in recent years, but sampled at a reduced level of effort compared to previous years (approximately one-third) due to limited funding. Here we present a summary of catch data collected in 2006. Bioenergetics models will be reported separately

Oregon↗
USGS2008

Dissolved Oxygen in Guadalupe Slough and Pond A3W, South San Francisco Bay, California, August and September 2007

Initial restoration of former salt evaporation ponds under the South Bay Salt Pond Restoration Project in San Francisco Bay included the changing of water-flow patterns and the monitoring of water quality of discharge waters from the ponds. Low dissolved oxygen (DO) concentrations became evident in discharge waters when the ponds first were opened in 2004. This was a concern, because of the potential for low-DO pond discharge to decrease the DO concentrations in the sloughs that receive water from the ponds. However, as of summer 2007, only limited point-measurements of DO concentrations had been made in the receiving sloughs adjacent to the discharge ponds. In this report, we describe two short studies aimed at understanding the natural variability of slough DO and the effect of pond discharge on the DO concentrations in the sloughs. Pond A3W (a discharge pond) and the adjacent Guadalupe Slough were instrumented in August and September 2007 to measure DO, temperature, conductivity, and pH. In addition, Mowry and Newark Sloughs were instrumented during the August study to document DO variability in nearby sloughs that were unaffected by pond discharge. The results showed that natural tidal variability in the slough appeared to dominate and control the slough DO concentrations. Water-quality parameters between Guadalupe Slough and Mowry and Newark Sloughs could not be directly compared because deployment locations were different distances from the bay. Pond-discharge water was identified in Guadalupe Slough using the deployed instruments, but, counter to the previous assumption, the pond discharge, at times, increased DO concentrations in the slough. The effects of altering the volume of pond discharge were overwhelmed by natural spring-neap tidal variability in the slough. This work represents a preliminary investigation by the U.S. Geological Survey of the effects of pond discharge on adjacent sloughs, and the results will be used in designing a comprehensive DO study to determine normal variability for this region.

Open-File Report↗
USGS2012

National assessment of shoreline change: A GIS compilation of vector shorelines and associated shoreline change data for the sandy shorelines of Kauai, Oahu, and Maui, Hawaii

Sandy ocean beaches are a popular recreational destination, and often are surrounded by communities that consist of valuable real estate. Development is increasing despite the fact that coastal infrastructure may be repeatedly subjected to flooding and erosion. As a result, the demand for accurate information regarding past and present shoreline changes is increasing. Working with researchers from the University of Hawaii, investigators with the U.S. Geological Survey's National Assessment of Shoreline Change Project have compiled a comprehensive database of digital vector shorelines and shoreline-change rates for the islands of Kauai, Oahu, and Maui, Hawaii. No widely accepted standard for analyzing shoreline change currently exists. Current measurement and rate-calculation methods vary from study to study, precluding the combination of study results into statewide or regional assessments. The impetus behind the National Assessment was to develop a standardized method for measuring changes in shoreline position that is consistent from coast to coast. The goal was to facilitate the process of periodically and systematically updating the measurements in an internally consistent manner. A detailed report on shoreline change for Kauai, Maui, and Oahu that contains a discussion of the data presented here is available and cited in the Geospatial Data section of this report.

Hawai'i↗
USGS2011

Principal facts for gravity stations collected in 2010 from White Pine and Lincoln Counties, east-central Nevada

Increasing demands on the Colorado River system within the arid Southwestern United States have focused attention on finding new, alternative sources of water. Particular attention is being paid to the eastern Great Basin, where important ground-water systems occur within a regionally extensive sequence of Paleozoic carbonate rocks and in the Cenozoic basin-fill deposits that occur throughout the region. Geophysical investigations to characterize the geologic framework of aquifers in eastern Nevada and western Utah began in a series of cooperative agreements between the U.S. Geological Survey and the Southern Nevada Water Authority in 2003. These studies were intended to better understand the formation of basins, define their subsurface shape and depth, and delineate structures that may impede or enhance groundwater flow. We have combined data from gravity stations established during the current study with previously available data to produce an up-to-date isostatic-gravity map of the study area, using a gravity inversion method to calculate depths to pre-Cenozoic basement rock and to estimate alluvial/volcanic fill in the valleys.

Open-File Report↗
USGS2011

An analysis of spatial relation predicates in U.S. Geological Survey feature definitions

The Semantic Web uses a data model called a triple, which consists of a subject -predicate - object structure. When represented as triples, geospatial data require a spatial relation term to serve as the predicate linking two spatial features. This document summarizes the approaches and procedures used during the identification of spatial relationships common between topographic features using terms from topographic data standards. This project identified verb-predicate arguments that could be used in the creation of data triples and ontologies for The National Map of the U.S. Geological Survey and also investigated the possibility of deriving ontology from predefined textual definitions. The primary purpose of this report is to present the data used for subsequent analysis. A summary of terms organized by basic categories is provided. Keywords: semantic technology, geospatial relations, topographic data

Open-File Report↗
USGS2011

Environmental settings of streams sampled for mercury in New York and South Carolina, 2005-09

This report summarizes the environmental settings of streams in New York and South Carolina, where the U.S. Geological Survey completed detailed investigations during 2005-09 into factors contributing to mercury bioaccumulation in top-predator fish and other stream organisms. Descriptions of location, land use/land cover, climate, precipitation, atmospheric deposition, hydrology, water temperature, and other characteristics are provided. Atmospheric deposition is the dominant mercury source in the studied basins where biota, sediment, soil, and water were sampled for mercury and for physical and chemical characteristics believed to be important in mercury methylation and transport.

New York, South Carolina↗
USGS2013

The National assessment of shoreline change—A GIS compilation of vector shorelines and associated shoreline change data for the Pacific Northwest coast

Sandy ocean beaches are a popular recreational destination and are often surrounded by communities that consist of valuable real estate. Development along sandy coastal areas is increasing despite the fact that coastal infrastructure may be repeatedly subjected to flooding and erosion. As a result, the demand for accurate information regarding past and present shoreline changes is increasing. Investigators with the U.S. Geological Survey's National Assessment of Shoreline Change Project have compiled a comprehensive database of digital vector shorelines and rates of shoreline change for the Pacific Northwest coast including the states of Washington and Oregon. No widely accepted standard for analyzing shoreline change currently exists. Current measurement and methods for calculating rates of change vary from study to study, precluding the combination of study results into statewide or regional assessments. The impetus behind the national assessment was to develop a standardized method that is consistent from coast to coast for measuring changes in shoreline position. The goal was to facilitate the process of periodically and systematically updating the measurements in an internally consistent manner. A detailed report on shoreline change for the Pacific Northwest coast that contains a discussion of the data presented here is available and cited in the Geospatial Data section of this report.

Oregon, Washington↗