Search USGS⌕ Search

SEARCH · Search USGS

Results for “Data Report”

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

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

At least 991 records · Page 55Linked to original sources
USGS1981

January 1981 water levels, and data related to water-level changes, western and south-central Kansas

This report provides hydrologic data related to water-level measurements in observation wells in western and south-central Kansas during January 1981. Annual water-level measurements are made by personnel from the Division of Water Resources, Kansas State Board of Agriculture, and from the U.S. Geological Survey . State-agency support for this cooperative program is provided by the Kansas Geological Survey. Water-level measurements are made in mid-winter of each year, mostly in January, to minimize the effect of seasonal pumping. However, a few water-level measurements that are made in mid-winter of some years may reflect either the effects of recent pumping by the observation well or by nearby wells, or the effects of barometric-pressure changes. Thus, a significant change in water-levels for a particular well during a 1-year period may represent only a temporary condition, and any indication of a developing trend should be based on a comparison of changes that occur over a period of several years. Hydrologic data in this report relate water-level changes from: (1) A "base-reference year" ( predevelopment year), (2) a year of abnormally high rainfall and minimum pumpage (1966 or 1974) , and (3) each of seven consecutive years of measurement (1975-81). The "base-reference year" is designated as 1940 for the southwestern area, 1944 for the south-central area, and 1950 for the northwestern and west-central areas (fig. 1). Water levels for the "base-reference year" are established by measurements made during that year and by interpretation of maps showing water-level altitudes. Depth to bedrock, used in computing saturated thickness of water-bearing deposits, are based on driller' s logs, reported depths of wells, and interpretation of maps showing the altitude of the bedrock surface.

Kansas↗
USGS1987

Ground-water levels in water years 1984-86 and estimated ground-water pumpage in water years 1984-85, Carson Valley, Douglas County, Nevada

Tabulations of groundwater level measurements made during the water years 1984-86 and summaries of estimated pumpage for water years 1984 and 1985 in Carson valley, Douglas County, Nevada, are included in this report. The data are being collected to provide a record of long-term groundwater changes and pumpage estimates that can be incorporated in a groundwater model change at a later date. (USGS)

Open-File Report↗
USGS1996

Analysis of the magnitude and frequency of peak discharge and maximum observed peak discharge in New Mexico

Equations for estimating the magnitude of peak discharges for recurrence intervals of 2, 5, 10, 25, 50, 100, and 500 years were updated for New Mexico. The equations represent flood response for eight distinct physiographic regions of New Mexico. Additionally, a regional equation was developed for basins less than 10 square miles and below 7,500 feet in mean basin elevation. Flood-frequency relations were updated for 201 gaging stations on unregulated streams in New Mexico and the bordering areas of adjacent States. The analysis described in this report used data collected through 1993. A low-discharge threshold was applied to frequency analysis of 140 gaging stations. Inclusion of these low peak flows affects the fitting of the lower tail and the upper tail of the distribution. Peak discharges can be estimated at an ungaged site on a stream that has a gaging station upstream or downstream. These estimates are derived using the drainage-area ratio and the drainage-area exponent from the regional regression equation of the respective region. Flood-frequency estimates for 201 gaged sites were weighted by estimates from the regional regression equation. The observed, predicted, and weighted flood-frequency data were computed for each gaging station. A maximum observed peak discharge as related to drainage area was determined for eight physiographic regions in New Mexico. Peak-discharge data collected at 201 gaging stations were used to develop a maximum peak-discharge relation as an alternative method of estimating the peak discharge of an extreme event.

Water-Resources Investigations Report↗
USGS2005

Log of Trench 04A across the Hayward Fault at Tyson's Lagoon (Tule Pond), Fremont, Alameda County, California

This publication makes available a detailed trench log (sheets 1 and 2) of a 110-m trench we excavated in 2004 across a tectonic sag pond in the Hayward fault zone. Also included are revised stratigraphic unit descriptions from this fifth field season of subsurface investigation of the Hayward fault at Tyson's Lagoon (Tule Pond). Preliminary findings based on fieldwork done in 2000 have been published (Lienkaemper and others: data archive, 2002a; report, 2002b), as were the logs and data for 2001-2003 (Lienkaemper and others, 2003, L03). A continuous exposure of the geologic section across the entire pond made in 2004 (Fig. 1, 04A) has revealed some critical miscorrelations of units made in the original on-line version of L03, hence users of these earlier trench data should only use the 2005 revised version 2.0 of L03 for correlation purposes. Lienkaemper, Williams, and Sickler interpreted the geology and logged the trenches. Fumal did most of the trench photography. The Hayward fault is recognized to be among the most hazardous in the United States (Working Group on California Earthquake Probabilities, 2003). Establishing a chronology of prehistoric or paleoearthquakes is of immediate use in resolving the likelihood of future large earthquakes Hayward fault. This document makes available geologic evidence for historical and prehistoric surface-rupturing earthquakes preserved at the site. A second, formal report on our conclusions based on these data is in preparation.

Open-File Report↗
USGS2002

Pesticides in surface water of the Yakima River basin, Washington, 1999–2000 — Their occurrence and an assessment of factors affecting concentrations and loads

The occurrence, distribution, and transport of pesticides in surface water of the Yakima River Basin were assessed using data collected during 1999­2000 as part of the U.S. Geological Survey National Water-Quality Assessment (NAWQA) Program. Samples were collected at 34 sites located throughout the basin in August 1999 using a Lagrangian sampling design. Samples also were collected weekly and monthly from May 1999 through January 2000 at three of the sites. This report includes data for 47 pesticide compounds from the analysis of filtered water using ocadecyl (C-18) solid-phase extraction and gas chromatography/mass spectrometry. Twenty-five pesticide compounds were detected in samples collected during the study. Detection frequencies ranged from about 1 percent for ethalfluralin, ethoprophos, and lindane to 82 percent for atrazine. Maximum concentrations of azinphos-methyl, carbaryl, diazinon, para,para'-dichlorodiphenyldichloroethylene (p,p'-DDE), and lindane exceeded chronic-toxicity guidelines for the protection of freshwater aquatic life. Twenty pesticide compounds were detected during sampling in August 1999. Atrazine was the most widely detected herbicide, and azinphos-methyl was the most widely detected insecticide. The median number of sites at which a particular pesticide compound was detected was six. Pesticide compounds detected at more than six sites include atrazine, simazine, terbacil, trifluralin, deethylatrazine, azinphos-methyl, carbaryl, diazinon, malathion, and p,p'-DDE. Because many factors affect the transport of pesticides from areas of application to surface water, there was not a simple correspondence between pesticide occurrence and use in the Yakima River Basin. For example, the high detection rates of atrazine, simazine, deethylatrazine, and p,p'-DDE are probably related more to their mobility and wide distribution in the hydrologic system than to their usage. Likewise, higher detection frequencies of the insecticides azinphos-methyl and carbaryl compared with chlorpyrifos appear to be related more to differences in their physical and chemical properties than to usage. The highest detection frequencies and concentrations of pesticides generally occurred during irrigation season, which is from mid-March to mid-October. Pesticides are applied during irrigation season, and runoff of excess irrigation water from fields transports them to surface water. Ground-water discharges also transport some pesticides to surface water. Atrazine, deethylatrazine, and simazine were frequently detected in samples collected after the irrigation season when there was little or no surface runoff and most of the flow in irrigation drains was derived from ground water. Daily loads of atrazine, terbacil, azinphos-methyl, and carbaryl discharged to the Yakima River from inflows between river mile 103.7 and river mile 72 varied widely between sites. For example, East Toppenish Drain discharged over 50 percent of the total load of terbacil to this reach of the Yakima River, but none of the total load of carbaryl and only about 4 percent of the total load of atrazine. Pesticide loads from the wastewater treatment plants were relatively small compared with loads from other inflows because their discharges were small. Pesticide losses, defined as the ratio of the amount discharged from a basin from May 1999 through January 2000 divided by the amount applied during 1999, were estimated for Moxee and Granger Drains and the Yakima River at Kiona. Losses ranged from less than 0.01 to 1.5 percent of pesticides applied and are comparable to those observed (0.01 to 2.2 percent) in irrigated agricultural basins in the Central Columbia Plateau of Washington State.

Washington↗
USGS2014

Water resources of West Feliciana Parish, Louisiana

Information concerning the availability, use, and quality of water in West Feliciana Parish, Louisiana, is critical for proper water-supply management. The purpose of this fact sheet is to present information that can be used by water managers, parish residents, and others for stewardship of this vital resource. Information on the availability, past and current use, use trends, and water quality from groundwater and surface-water sources in the parish is discussed. Previously published reports and data stored in the U.S. Geological Survey’s National Water Information System ( http://waterdata.usgs.gov/nwis ) are the primary sources of the information presented here.

Louisiana↗
USGS2014

Maximum known stages and discharges of New York streams and their annual exceedance probabilities through September 2011

Maximum known stages and discharges at 1,400 sites on 796 streams within New York are tabulated. Stage data are reported in feet. Discharges are reported as cubic feet per second and in cubic feet per second per square mile. Drainage areas range from 0.03 to 298,800 square miles; excluding the three sites with larger drainage areas on the St. Lawrence and Niagara Rivers, which drain the Great Lakes, the maximum drainage area is 8,288 square miles (Hudson River at Albany). Most data were obtained from U.S. Geological Survey (USGS) compilations and records, but some were provided by State, local, and other Federal agencies and by private organizations. The stage and discharge information is grouped by major drainage basins and U.S. Geological Survey site number, in downstream order. Site locations and their associated drainage area, period(s) of record, stage and discharge data, and flood-frequency statistics are compiled in a Microsoft Excel spreadsheet. Flood frequencies were derived for 1,238 sites by using methods described in Bulletin 17B (Interagency Advisory Committee on Water Data, 1982), Ries and Crouse (2002), and Lumia and others (2006). Curves that “envelope” maximum discharges within their range of drainage areas were developed for each of six flood-frequency hydrologic regions and for sites on Long Island, as well as for the State of New York; the New York curve was compared with a curve derived from a plot of maximum known discharges throughout the United States. Discharges represented by the national curve range from at least 2.7 to 4.9 times greater than those represented by the New York curve for drainage areas of 1.0 and 1,000 square miles. The relative magnitudes of discharge and runoff in the six hydrologic regions of New York and Long Island suggest the largest known discharges per square mile are in the southern part of western New York and the Catskill Mountain area, and the smallest are on Long Island.

New York↗
USGS2018

Quality-assurance plan for groundwater activities, U.S. Geological Survey Dakota Water Science Center

As the Nation’s principal earth-science information agency, the U.S. Geological Survey (USGS) is depended upon to collect accurate data and produce factual and impartial interpretive reports. Methods for data collection and analysis that were developed by the USGS have become standard techniques used by numerous Federal, State, and local agencies and by private enterprises. The USGS has implemented a program designed to ensure that all scientific work done by or for USGS Water Science Centers is done in accordance with a quality-assurance plan. The implementation of a groundwater quality-assurance plan will enhance groundwater data collected by the USGS. This report is a quality-assurance plan for groundwater activities conducted by the USGS Dakota Water Science Center and is meant to complement qualityassurance plans for surface-water and water-quality activities and similar plans for the Dakota Water Science Center and general project activities throughout the USGS.

Open-File Report↗
USGS2000

Analytical results and sample locality map for rock, stream-sediment, and soil samples, Northern and Eastern Colorado Desert BLM Resource Area, Imperial, Riverside, and San Bernardino Counties, California

In 1996-1998 the U.S. Geological Survey (USGS) conducted a geochemical study of the Bureau of Land Management's (BLM) 5.5 million-acre Northern and Eastern Colorado Desert Resource Area (usually referred to as the NECD in this report), Imperial, Riverside, and San Bernardino Counties, southeastern California (figure 1). This study was done in support of the BLM's Coordinated Management Plan for the area. This report presents analytical data from this study. To provide comprehensive coverage of the NECD, we compiled and examined all available geochemical data, in digital form, from previous studies in the area, and made sample-site plots to aid in determining where sample-site coverage and analyses were sufficient, which samples should be re-analyzed, and where additional sampling was needed. Previous investigations conducted in parts of the current study area included the National Uranium Resource Evaluation (NURE) program studies of the Needles and Salton Sea 1° x 2° quadrangles; USGS studies of 12 BLM Wilderness Study Areas (WSAs) (Big Maria Mountains, Chemehuevi Mountains, Chuckwalla Mountains, Coxcomb Mountains, Mecca Hills, Orocopia Mountains, Palen-McCoy, Picacho Peak, Riverside Mountains, Sheephole Valley (also known as Sheep Hole/Cadiz), Turtle Mountains, and Whipple Mountains); and USGS studies in the Needles and El Centro 1° x 2° quadrangles done during the early 1990s as part of a project to identify the regional geochemistry of southern California. Areas where we did new sampling of rocks and stream sediments are mainly in the Chocolate Mountain Aerial Gunnery Range and in Joshua Tree National Park, which extends into the west-central part of the NECD, as shown in figure 1 and figure 2. This report contains analytical data for 132 rock samples and 1,245 stream-sediment samples collected by the USGS, and 362 stream-sediment samples and 189 soil samples collected during the NURE program. All samples are from the Northern and Eastern Colorado Desert BLM Resource Area and vicinity. Included in the 1,245 stream-sediment samples collected by the USGS are 284 samples collected as part of the current study, 817 samples collected as part of investigations of the12 BLM WSAs and re-analyzed for the present study, 45 samples from the Needles 1° x 2° quadrangle, and 99 samples from the El Centro 1° x 2° quadrangle. The NURE stream-sediment and soil samples were re-analyzed as part of the USGS study in the Needles quadrangle. Analytical data for samples from the Chocolate Mountain Aerial Gunnery Range, which is located within the area of the NECD, were previously reported (King and Chaffee, 1999a). For completeness, these results are also included in this report. Analytical data for samples from the area of Joshua Tree National Park that is within the NECD have also been reported (King and Chaffee, 1999b). These results are not included in this report. The analytical data presented here can be used for baseline geochemical, mineral resource, and environmental geochemical studies.

California↗
USGS2015

Potentiometric surface, 2013, and water-level differences, 1991-2013, of the Carrizo-Wilcox aquifer in northwest Louisiana

The Carrizo-Wilcox aquifer is the primary source of fresh groundwater for public supply as well as industrial, agricultural, and domestic uses in several parishes in northwestern Louisiana, including Bienville, Bossier, Caddo, De Soto, Natchitoches, Red River, Sabine, and Webster. In 2010, about 19 million gallons per day (Mgal/d) were withdrawn from the Carrizo-Wilcox aquifer in Louisiana. This is an increase of over 6 Mgal/d from 1990 withdrawal amounts. The largest increase in withdrawals occurred in Caddo (3.79 Mgal/d) and De Soto Parishes (2.32 Mgal/d), whereas the largest decrease in withdrawals occurred in Natchitoches Parish (1.17 Mgal/d). Groundwater withdrawals from the Carrizo-Wilcox aquifer have caused water-level declines throughout much of the aquifer in the study area. Additional knowledge about the effects of withdrawals on water levels and flow directions in the Carrizo-Wilcox aquifer are needed to assess current conditions in the aquifer. In 2012, the U.S. Geological Survey (USGS) in cooperation with the Louisiana Department of Natural Resources began a study to document current water levels and water-level changes in selected aquifers. This report presents data and maps that illustrate the potentiometric surface of the Carrizo-Wilcox aquifer during March–May 2013 and water-level differences from 1991 to 2013. The potentiometric surface map can be used for determining the direction of groundwater flow, hydraulic gradients, and effects of withdrawals on the groundwater resource. The rate of groundwater movement also can be estimated from the gradient when the hydraulic conductivity is applied. Water-level data collected for this study are stored in the USGS National Water Information System (NWIS) ( http://waterdata.usgs.gov/nwis ) and are on file at the USGS office in Baton Rouge, La.

Louisiana↗
USGS1997

Results of soil, ground-water, surface-water, and streambed-sediment sampling at Air Force Plane 85, Columbus, Ohio, 1996

The U.S. Geological Survey (USGS), in cooperation with Aeronautical Systems Center, Environmental Management Directorate, Restoration Division, prepared the Surface- and Ground- Water Monitoring Work Plan for Air Force Plant 85 (AFP 85 or Plant), Columbus, Ohio, under the Air Force Installation Restoration Program to characterize any ground-water, surface-water, and soil contamination that may exist at AFP 85. The USGS began the study in November 1996. The Plant was divided into nine sampling areas, which included some previously investi gated study sites. The investigation activities included the collection and presentation of data taken during drilling and water-quality sampling. Data collection focused on the saturated and unsatur ated zones and surface water. Twenty-three soil borings were completed. Ten monitoring wells (six existing wells and four newly constructed monitoring wells) were selected for water-quality sam pling. Surface-water and streambed-sediment sampling locations were chosen to monitor flow onto and off of the Plant. Seven sites were sampled for both surface-water and streambed-sediment quality. This report presents data on the selected inorganic and organic constituents in soil, ground water, surface water, and streambed sediments at AFP 85. The methods of data collection and anal ysis also are included. Knowledge of the geologic and hydrologic setting could aid Aeronautical Systems Center, Environmental Management Directorate, Restoration Division, and its governing regulatory agencies in future remediation studies.

Open-File Report↗
USGS1984

Geohydrology of the valley-fill aquifer in the Cohocton area, upper Cohocton River, Steuben County, New York

The Cohocton valley-fill aquifer, composed of outwash, kame, and alluvial sand and gravel, is highly productive and is in hydraulic contact with the Cohocton River. Potential well yields range from 50 to more than 1,000 gallons per minute. Most of the aquifer is under shallow water-table conditions and vulnerable to surface contamination. Thickness ranges from 20 to 100 feet. The aquifer lies in an area containing only small communities and therefore is not heavily pumped. Geohydrologic data are compiled on six maps at 1:24,000 scale and in geologic sections. The maps depict surficial geology, soil-infiltration capacity, potentiometric surface, aquifer thickness, well yields, and land use. The maps are designed to help planners evaluate developments that may affect the aquifer, particularly potential contamination sources. This set is one in a series of four that depict selected aquifers in western New York. It supplements a series that is being done by the U.S. Geological Survey in cooperation with State agencies. The maps are based largely on published reports, file data in several State agencies, and field notes. (USGS)

Water-Resources Investigations Report↗
USGS1987

Hydrologic data for selected streams in the coal area of southeastern Oklahoma, July 1978 to September 1982

Hydrologic data on quantity and quality of surface waters were collected in the coal resource area of southeastern Oklahoma during an investigation of the effects of coal surface mining on the hydrology of the area. The objective of the study was to determine the characteristics of the regional hydrologic system and to detect and document changes in the system that may occur as the result of coal surface mining. This report presents data which were collected at 13 sites in 4 counties between July 1978 and September 1982. The data include: (1) mean daily stream discharge; (2) physical properties, selected field constituents, and concentration of suspended sediment of water samples; (3) concentration of selected common constituents, nutrients, and trace elements of water samples; (4) mean daily specific conductance, pH, water temperature, and dissolved oxygen; and (5) analyses of biological samples.

Open-File Report↗
USGS1989

Arsenic and chloride data for five stream sites in the Madison River drainage, Montana, 1988

Enriched geothermal waters in Yellowstone National Park contribute large quantities of arsenic to the Madison River. Because arsenic may be acutely or chronically toxic to humans when ingested, it is of concern in the upper Missouri River basin where the water is used for domestic purposes. In passage of water downstream, concentrations of arsenic in the Madison and Missouri Rivers are diluted by tributary inflows. However, insufficient information existed to describe concentrations during runoff at specific locations. As a result, a monitoring network was established to better define arsenic concentrations during the 1988 peak runoff and during periods prior to and following the runoff. In addition to arsenic, samples were analyzed for chloride because of its association with geothermal water and specific conductance because it is a surrogate measure of dissolved-solids concentration. This report presents data acquired during 1988 at five sampling stations in the Madison River drainage. (USGS)

Open-File Report↗
USGS2011

Regional skew for California, and flood frequency for selected sites in the Sacramento-San Joaquin River Basin, based on data through water year 2006

Improved flood-frequency information is important throughout California in general and in the Sacramento-San Joaquin River Basin in particular, because of an extensive network of flood-control levees and the risk of catastrophic flooding. A key first step in updating flood-frequency information is determining regional skew. A Bayesian generalized least squares (GLS) regression method was used to derive a regional-skew model based on annual peak-discharge data for 158 long-term (30 or more years of record) stations throughout most of California. The desert areas in southeastern California had too few long-term stations to reliably determine regional skew for that hydrologically distinct region; therefore, the desert areas were excluded from the regional skew analysis for California. Of the 158 long-term stations used to determine regional skew, 145 have minimally regulated annual-peak discharges, and 13 stations are dam sites for which unregulated peak discharges were estimated from unregulated daily maximum discharge data furnished by the U.S. Army Corp of Engineers. Station skew was determined by using an expected moments algorithm (EMA) program for fitting the Pearson Type 3 flood-frequency distribution to the logarithms of annual peak-discharge data. The Bayesian GLS regression method previously developed was modified because of the large cross correlations among concurrent recorded peak discharges in California and the use of censored data and historical flood information with the new expected moments algorithm. In particular, to properly account for these cross-correlation problems and develop a suitable regression model and regression diagnostics, a combination of Bayesian weighted least squares and generalized least squares regression was adopted. This new methodology identified a nonlinear function relating regional skew to mean basin elevation. The regional skew values ranged from -0.62 for a mean basin elevation of zero to 0.61 for a mean basin elevation of 11,000 feet. This relation between skew and elevation reflects the interaction of snow with rain, which increases with increased elevation. The equivalent record length for the new regional skew ranges from 52 to 65 years of record, depending upon mean basin elevation. The old regional skew map in Bulletin 17B, published by the Hydrology Subcommittee of the Interagency Advisory Committee on Water Data (1982), reported an equivalent record length of only 17 years. The newly developed regional skew relation for California was used to update flood frequency for the 158 sites used in the regional skew analysis as well as 206 selected sites in the Sacramento-San Joaquin River Basin. For these sites, annual-peak discharges having recurrence intervals of 2, 5, 10, 25, 50, 100, 200, and 500 years were determined on the basis of data through water year 2006. The expected moments algorithm was used for determining the magnitude and frequency of floods at gaged sites by using regional skew values and using the basic approach outlined in Bulletin

Scientific Investigations Report↗
USGS2003

Paleomagnetism and geochronology of an Early Proterozoic quartz diorite in the southern Wind River Range, Wyoming, USA

We present geochronologic and paleomagnetic data from a north-trending quartz diorite intrusion that cuts Archean metasedimentary and metaigneous rocks of the South Pass Greenstone Belt of the Wyoming craton. The quartz diorite was previously thought to be either Archean or Early Proterozoic (?) in age and is cut by north and northeast-trending Proterozoic diabase dikes of uncertain age, for which we also report paleomagnetic data. New U-Pb analyses of baddeleyite and zircon from the quartz diorite yield a concordia upper intercept age of 2170 ?? 8 Ma (95% confidence). An 40Ar/39Ar amphibole date from the same sample yields a similar apparent age of about 2124 ?? 30 Ma (2??), thus confirming that the intrusion is Early Proterozoic in age and that it has probably not been thermally disturbed since emplacement. A magmatic event at ca. 2.17 Ga has not previously been documented in the Wyoming craton. The quartz diorite and one of the crosscutting diabase dikes yield essentially identical, well-defined characteristic remanent magnetizations. Results from eight sites in the quartz diorite yield an in situ mean direction of north declination and moderate to steep positive inclination (Dec.=355??, Inc.=65??, k=145, ??95=5??) with a paleomagnetic pole at 84??N, 215??E (??m=6??, ??p=7??). Data from other diabase dike sites are inconsistent with the quartz diorite results, but the importance of these results is uncertain because the age of the dikes is not well known. Interpretation of the quartz diorite remanent magnetization is problematic. The in situ direction is similar to expected directions for magnetizations of Late Cretaceous/early Tertiary age. However, there is no compelling evidence to suggest that these rocks were remagnetized during the late Mesozoic or Cenozoic. Assuming this magnetization to be primary, then the in situ paleomagnetic pole is strongly discordant with poles of 2167, 2214, and 2217 Ma from the Canadian Shield, and is consistent with proposed separation of the Wyoming Craton and Laurentia prior to about 1.8 Ga. Correcting the quartz diorite pole for the possible effects of Laramide-age tilting of the Wind River Range, based on the attitude of nearby overlying Cambrian Flathead Sandstone (dip=20??, N20??E), gives a tilt corrected pole of 75??N, 58??E (??m=4??, ??p=6??), which is also discordant with respect to time-equivalent poles from the Superior Province. Reconstruction of the Superior and Wyoming Province using a rotation similar to that proposed by Roscoe and Card [Can. J. Earth Sci. 46(1993)2475] is problematic, but reconstruction of the Superior and Wyoming Provinces based on restoring them to their correct paleolatitude and orientation using a closest approach fit indicates that the two cratons could have been adjacent at about 2.17 Ga prior to rifting at about 2.15 Ga. The paleomagnetic data presented are consistent with the hypothesis that the Huronian and Snowy Pass Supergroups could have evolved as part of a single epicratonic sedimentary basin during the Early Proterozoic. ?? 2002 Elsevier Science B.V. All rights reserved.

Tectonophysics↗
USGS1996

Tennessee

The U.S. Geological Survey (USGS), established in 1879, is an agency of the U.S. Department of the Interior. For more than a century, the USGS has provided reports, maps, data, and other information to aid in the development, management, and portection of the Nation's water, energy, mineral, and land resources. This brochure outlines the USGS in Tennessee and highlights hydrologic investigations.

Open-File Report↗
USGS1982

Electrical studies at the proposed Wahmonie and Calico Hills nuclear waste sites, Nevada Test Site, Nye County, Nevada

Two sites in the southwest quadrant of the Nevada Test Site (NTS) were investigated as potential repositories for high-level nuclear waste. These are designated the Wahmonie and Calico Hills sites. The emplacement medium at both sites was to be an inferred intrusive body at shallow depth; the inference of the presence of the body was based on aeromagnetic and regional gravity data. This report summarizes results of Schlumberger VES, induced polarization dipole-dipole traverses and magnetotelluric soundings made in the vicinity of the sites in order to characterize the geoelectric section. At the Wahmonie site VES work identified a low resistivity unit at depth surrounding the inferred intrusive body. The low resistivity unit is believed to be either the argillite (Mississippian Eleana Formation) or a thick unit of altered volcanic rock (Tertiary). Good electrical contrast is provided between the low resistivity unit and a large volume of intermediate resistivity rock correlative with the aeromagnetic and gravity data. The intermediate resistivity unit (100-200 ohm-m) is believed to be the intrusive body. The resistivity values are very low for a fresh, tight intrusive and suggest significant fracturing, alteration and possible mineralization have occurred within the upper kilometer of rock. Induced polarization data supports the VES work, identifies a major fault on the northwest side of the inferred intrusive and significant potential for disseminated mineralization within the body. The mineralization potential is particularly significant because as late as 1928, a strike of high grade silver-gold ore was made at the site. The shallow electrical data at Calico Hills revealed no large volume high resistivity body that could be associated with a tight intrusive mass in the upper kilometer of section. A drill hole UE 25A-3 sunk to 762 m (2500 ft) at the site revealed only units of the Eleana argillite thermally metamorphosed below 396 m (1300 ft) and in part highly magnetic. Subsequent work has shown that much if not all of the magnetic and gravity anomalies can be attributed to the Eleana Formation. The alteration and doming, however, still argue for an intrusive but at greater depth than originally thought. The electrical, VES, and IP data show a complex picture due to variations in structure and alteration within the Eleana and surrounding volcanic units. These data do not suggest the presence of an intrusive in the upper kilometer of section. The magnetotelluric data however gives clear evidence for a thick, resistive body in the earth's crust below the site. While the interpreted depth is very poorly constrained due to noise and structural problems, the top of the resistive body is on the order of 2.5 km deep. The IP data also identifies area of increased polarizability at Calico Hills, which may also have future economic mineralization.

Open-File Report↗