Aeromagnetic map of western Dorchester County, Maryland, and parts of adjacent counties
Explore the source record for details and available documents.
Geophysical Investigations Map↗
SEARCH · Search USGS
Results for “Geologic Investigation”
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.
Gravity anomaly map of the United States; Part A: Conterminous United States
No abstract available.
Conterminous United States↗
Availability of ground water for irrigation, municipal, or industrial use in the Navajo and Hopi Indian Reservations, Arizona, New Mexico, and Utah
The Navajo and Hopi Indian reservations are located mainly in northeastern Arizona, although the Navajo Indian reservation extends into northwestern New Mexico and southeastern Utah (see location map). The area of this report coincides with the areas of the Navajo and Hopi Indian reservations except in part of New Mexico, where the areas was extended eastward to longitude 108° and southward to Interstate Highway 40 and in southeastern Utah. This investigation was conducted by the U.S. Geological Survey at the request of the Bureau of Indian Affairs. The study was undertaken to evaluate the potential for large-scale ground-water development in the Navajo and Hope Indian Reservations. The results given in this report are intended as preliminary guidelines for the development of ground water in sufficient quantity and of suitable quality for irrigation, municipal, and industrial uses. Data are not included for areas in which less than 25 gal min -1 (gallons per minute) or 95 l min -1 (litres per minute) can be developed.
Arizona, New Mexico, Utah↗
Core descriptions, core photographs, physical property logs and surface textural data of sediment cores recovered from the continental shelf of the Monterey Bay National Marine Sanctuary during the research cruises M-1-95-MB, P-2-95-MB, and P-1-97-MB
In response to the 1992 creation of the Monterey Bay National Marine Sanctuary (MBNMS), the United States Geological Survey (USGS) initiated a multiyear investigation of the Sanctuary continental margin. As part of the investigative effort, this report summarizes the shipboard procedures, subsequent laboratory analyses, and data results from three seafloor sampling cruises conducted on the continental shelf between Monterey peninsula, CA and San Francisco, CA. The cruises were conducted in 1995 aboard the NOAA Ship McArthur (M-1-95-MB) and in 1995 and 1997 aboard the R/V Point Sur (P-2-95-MB and P-1-97-MB). Scientists and representatives from the Environmental Protection Agency (EPA), the National Oceanic and Atmospheric Administration (NOAA), the California Department of Fish and Game (CDFG), the University of California Santa Cruz (UCSC), and the San Jose State University Moss Landing Marine Laboratory (SJSU-MLML) supported the research effort. In this report we present sediment descriptions, sediment textural data, physical property logs, station metadata, and photographs of subcores from a total of three hundred and eighty four sample stations. At these sites either a box corer, MultiCore™r, grab sampler or a combination of these sampling devices were used to collect the sea floor sediments. The report is presented in an interactive web-based format with each mapped core station linked to the corresponding description and photo, and to a spreadsheet of surface texture and other sampling data.
California↗
Aeromagnetic survey map of the central California Coast Ranges
This aeromagnetic survey was flown as part of a Cooperative Research and Development Agreement (CRADA) with the Pacific Gas and Electric Company and is intended to promote further understanding of the geology and structure in the central California Coast Ranges by serving as a basis for geophysical interpretations and by supporting geological mapping, mineral and water resource investigations, and other topical studies. Local spatial variations in the Earth's magnetic field (evident as anomalies on aeromagnetic maps) reflect the distribution of magnetic minerals, primarily magnetite, in the underlying rocks. In many cases the volume content of magnetic minerals can be related to rock type, and abrupt spatial changes in the amount of magnetic minerals can commonly mark lithologic or structural boundaries. Bodies of serpentinite and other mafic and ultramafic rocks tend to produce the most intense magnetic anomalies, but such generalizations must be applied with caution because rocks with more felsic compositions, such as the porphyritic granodiorite-granite of the La Panza Range, and even some sedimentary units, also can cause measurable magnetic anomalies.
California↗
Palos Verdes Shelf oceanographic study; data report for observations December 2007–April 2008
Beginning in 1997, the Environmental Protection Agency (EPA) defined a contaminated section of the Palos Verdes Shelf region in southern California as a Superfund Site, initiating a continuing investigation of this area. The investigation involved the EPA, the U.S. Geological Survey (USGS), Science Applications International Corporation (SAIC), Los Angeles County Sanitation Districts (LACSD) data, and other allied agencies. In mid-2007, the Palos Verdes Shelf project team identified the need for additional data on the sediment properties and oceanographic conditions at the Palos Verdes Superfund Site and deployed seven bottom platforms, three subsurface moorings, and three surface moorings on the shelf. This additional data was needed to support ongoing modeling and feasibility studies and to improve our ability to model the fate of the effluent-affected deposit over time. It provided more detail on the spatial variability and magnitude of resuspension of the deposit during multiple storms that are expected to transit the region during a winter season. The operation began in early December 2007 and ended in early April 2008. The goal was to measure the sediment response (threshold of resuspension, suspended-sediment concentrations, and suspended-sediment transport rates) to bed stresses associated with waves and currents. Other objectives included determining the structure of the bottom boundary layer (BBL) relating nearbed currents with those measured at 10 m above bottom (mab) and comparing those with the long-term data from the LACSD Acoustic Doppler Current Profiler (ADCP) deployments for nearbed current speed and direction. Low-profile tripods with high-frequency ADCPs co-located with two of the large tripods were selected for this goal. This report describes the data obtained during the field program, the instruments and data-processing procedures used, and the archive that contains the data sets that have passed our quality-assurance procedures.
California↗
Magnetic map of the Irish Hills and surrounding areas, San Luis Obispo County, central California
A magnetic map of the Irish Hills and surrounding areas was created as part of a cooperative research and development agreement with the Pacific Gas and Electric Company and is intended to promote further understanding of the areal geology and structure by serving as a basis for geophysical interpretations and by supporting geological mapping, mineral and water resource investigations, and other topical studies. Local spatial variations in the Earth's magnetic field (evident as anomalies on magnetic maps) reflect the distribution of magnetic minerals, primarily magnetite, in the underlying rocks. In many cases the volume content of magnetic minerals can be related to rock type, and abrupt spatial changes in the amount of magnetic minerals can be related to either lithologic or structural boundaries. Magnetic susceptibility measurements from the area indicate that bodies of serpentinite and other mafic and ultramafic rocks tend to produce the most intense magnetic anomalies, but such generalizations must be applied with caution because some sedimentary units also can produce measurable magnetic anomalies. Remanent magnetization does not appear to be a significant source for magnetic anomalies because it is an order of magnitude less than the induced magnetization. The map is a mosaic of three separate surveys collected by (1) fixed-wing aircraft at a nominal height of 305 m, (2) by boat with the sensor at sea level, and (3) by helicopter. The helicopter survey was flown by New-Sense Geophysics in October 2009 along flight lines spaced 150-m apart and at a nominal terrain clearance of 50 to 100 m. Tie lines were flown 1,500-m apart. Data were adjusted for lag error and diurnal field variations. Further processing included microleveling using the tie lines and subtraction of the reference field defined by International Geomagnetic Reference Field (IGRF) 2005 extrapolated to August 1, 2008.
California↗
Geochemical, isotopic, and dissolved gas characteristics of groundwater in a fractured crystalline-rock aquifer, Savage Municipal Well Superfund site, Milford, New Hampshire, 2011
Tetrachloroethylene (PCE), a volatile organic compound, was detected in groundwater from deep (more than (>) 300 feet (ft) below land surface) fractures in monitoring wells tapping a crystalline-rock aquifer beneath operable unit 1 (OU1) of the Savage Municipal Well Superfund site (Weston, Inc., 2010). Operable units define remedial areas of contaminant concern. PCE contamination within the fractured-rock aquifer has been designated as a separate operable unit, operable unit 3 (OU3; Weston, Inc., 2010). PCE contamination was previously detected in the overlying glacial sand and gravel deposits and basal till, hereafter termed the Milford-Souhegan glacial-drift (MSGD) aquifer (Harte, 2004, 2006). Operable units 1 and 2 encompass areas within the MSGD aquifer, whereas the extent of the underlying OU3 has yet to be defined. The primary original source of contamination has been identified as a former manufacturing facility—the OK Tool manufacturing facility; hence OU1 sometimes has been referred to as the OK Tool Source Area (New Hampshire Department of Environmental Services, undated). A residential neighborhood of 30 to 40 houses is located in close proximity (one-quarter of a mile) from the PCE-contaminated monitoring wells. Each house has its own water-supply well installed in similar rocks as those of the monitoring wells, as indicated by the New Hampshire State geologic map (Lyons and others, 1997). An investigation was initiated in 2010 by the U.S. Environmental Protection Agency (USEPA) region 1, and the New Hampshire Department of Environmental Services (NHDES) to assess the potential for PCE transport from known contaminant locations (monitoring wells) to the residential wells. The U.S. Geological Survey (USGS) and the NHDES entered into a cooperative agreement in 2011 to assist in the evaluation of PCE transport in the fractured-rock aquifer. Periodic sampling over the last decade by the USEPA and NHDES has yet to detect PCE in groundwater from the residential-supply wells (as of 2012). However, part of assessing the potential for PCE transport involves understanding the origin of the groundwater in the monitoring and residential wells. One of the tools in delineating the movement of groundwater to wells, particularly in complex, highly heterogeneous fractured-rock aquifers, is the understanding of the geochemical and isotopic composition of groundwater (Lipfert and Reeve, 2004; Harte and others, 2012). This report summarizes findings from analyses of geochemical, isotopic, and dissolved gas characteristics of groundwater. Samples of groundwater were collected in 2011 from monitoring wells and nearby residential-supply wells in proximity to OU1.
New Hampshire↗
Aeromagnetic survey map of Sacramento Valley, California
Three aeromagnetic surveys were flown to improve understanding of the geology and structure in the Sacramento Valley. The resulting data serve as a basis for geophysical interpretations, and support geological mapping, water and mineral resource investigations, and other topical studies. Local spatial variations in the Earth's magnetic field (evident as anomalies on aeromagnetic maps) reflect the distribution of magnetic minerals, primarily magnetite, in the underlying rocks. In many cases the volume content of magnetic minerals can be related to rock type, and abrupt spatial changes in the amount of magnetic minerals commonly mark lithologic or structural boundaries. Bodies of serpentinite and other mafic and ultramafic rocks tend to produce the most intense positive magnetic anomalies (for example, in the northwest part of the map). These rock types are the inferred sources, concealed beneath weakly magnetic, valley-fill deposits, of the most prominent magnetic features in the map area, the magnetic highs that extend along the valley axis. Cenozoic volcanic rocks are also an important source of magnetic anomalies and coincide with short-wavelength anomalies that can be either positive (strong central positive anomaly flanked by lower-amplitude negative anomalies) or negative (strong central negative anomaly flanked by lower-amplitude positive anomalies), reflecting the contribution of remanent magnetization. Rocks with more felsic compositions or even some sedimentary units also can cause measurable magnetic anomalies. For example, the long, linear, narrow north-trending anomalies (with amplitudes of <50 nanoteslas [nT]) along the western margin of the valley coincide with exposures of the Mesozoic Great Valley sequence. Note that isolated, short-wavelength anomalies, such as those in the city of Sacramento and along some of the major roads, are caused by manmade features.
California↗
Mercury in U.S. coal—Priorities for new U.S. Geological Survey studies
In 2011, the U.S. Environmental Protection Agency (EPA) introduced emissions standards, known as Mercury and Air Toxics Standards (MATS), for a range of toxic constituents from coal-fired utility power stations and other combustion sources. This report presents the findings of an expert panel convened in September 2014 to assess the role of the U.S. Geological Survey (USGS) in new coal investigations that would be useful to stakeholders under MATS. Panel input is provided as summaries of responses to a questionnaire distributed to participants. The panel suggests that the USGS continue its work on trace elements in coal and include more information about delivered coals and boiler feed coals, in comparison to previous USGS compilations that emphasized sampling representative of coals in the ground. To be useful under multipollutant regulatory standards, investigation of a range of constituents in addition to mercury would be necessary. These include other toxic metals proposed for regulation, such as arsenic, nickel, cadmium, and chromium, as well as the halogens chlorine and fluorine, which upon emission form harmful acid gases. Halogen determinations are also important because they influence mercury speciation in flue gas, which allows the effectiveness of mercury controls to be assessed and predicted. The panel suggests that the Illinois Basin and the Powder River Basin should have the highest priority for new coal quality investigations in the near term by the USGS, on the basis of current economic conditions and overall economic importance, respectively. As a starting point for new investigations, brief summaries of the distribution of mercury in each coal basin, and their potential for further investigation, are presented.
Open-File Report↗
Water-quality distributions in the East Branch Black River near the Chemical Recovery Systems site in Elyria, Ohio, 2021
Autonomous underwater vehicles are uniquely designed to provide spatially dense water-quality data along with bathymetry and velocimetry. The U.S. Environmental Protection Agency Region 5 requested technical assistance from the U.S. Geological Survey in support of ongoing investigations at the Chemical Recovery Systems site to collect spatially dense water-quality and bathymetry data in the East Branch Black River in Elyria, Ohio. This report was prepared in cooperation with the U.S. Environmental Protection Agency to present the results of the autonomous underwater vehicle survey near the Chemical Recovery Systems site on March 22, 2021. Plots of distributions of water temperature, specific conductance, pH, and dissolved oxygen are presented that may help guide and focus future U.S. Environmental Protection Agency efforts at the site to determine the degree of groundwater/surface-water interaction.
Ohio↗
Preliminary report on a lead-zinc occurrence at Berg Basin, Wrangell district, southeastern Alaska
A brief examinatin of lead-zinc occurrence at Berg Basin, Wrangell district, southeastern Alaska, was undertaken in 1947 as part of the U.S. Geological Survey's program of minerals investigations in Alaska. No lead-zinc ore body has yet been proved at Berg Basin, but because of recent interest in that area this preliminary report has been prepared for the purpose of making available immediately all data collected to date. A more complete report is in preparation.
Alaska↗
Geology of the Dry Valley quadrangle, Idaho; a preliminary report
The Dry Valley quadrangle is one of seven 71-minute quadrangles in southeastern Idaho being mapped by the U. S. Geological Survey as part of an investigation of the western phosphate field. This work was done on behalf of the Division of Raw Materials of the Atomic Energy Commission. Most of the quadrangle was mapped on a new 1:12,000 topographic base during the summer and fall of 1950 by E. R. Cressman and R. A. Gulbrandsen with the assistance of K. B. Krauskopf, K. Lutz, and J. W. Hill. The field work was completed in the fall of 1951 by Cressman and assisted by R. G. Waring and M. A. Warner. This quadrangle is the NEI of the Slug Creek 15-minute quadrangle, which was mapped by Mansfield (1927) at a scale of 1:62,500.
Idaho↗
Progress report of cooperative ground-water investigations for Connecticut for the year ended June 30, 1954
Ground-water investigations were continued under the Water Commission- U.S. Geological Survey Cooperative Program at four project area in Connecticut during the year ended June 30, 1954. Substantial progress was made in the collection of basic water information in the lower Farmington River basin. Both surface and subsurface geological area were assembled for use by prospective well owners. The preparation of a report on the geology and ground-water resources of the agricultural area of north-central Connecticut was continued during the year. As a continuation of investigations on the ground-water resources of the industrial areas of New Haven and Waterbury, observations of water level and samples of water were taken bi-monthly from 5 well at 5 industrial plants in Waterbury and anaysed for sulfate concentration in order to measure the degree of infiltration of acid-contaminated water to the water-bearing formations.
Connecticut↗
Memorandum on availability of ground water for irrigation in certain areas of eastern Arkansas
This memorandum was prepared in response to a request from the Soil Conservation Service, Little Rock, Ark., for information on the future prospects of irrigation of rice with water from wells in certain areas in the basins of the Bache, St. Francis, and L'Anguille Rivers, Big and Dials Creeks, and Bayou Meto and the Bouef-Tensas-Macon basin. It was prepared as a aprt of the Statewide ground-water investigation in cooperation with the Arkansas Geological and Conservation Commission ad the University of Arkansas. The specific areas and water requirement specified by the Soil Conservation Service are listed in the appendix.
Arkansas↗
Preliminary results of induced polarization-resistivity surveys in the Northgate district, Colorado
Induced polarization (I.P.) and resistivity surveys were made at selected locations in the Northgate district, Jackson County, Colorado. The objectives of the study were (1) to determine the feasibility of detecting and delineating pyrite-altered zones adjacent to fluorsparmineralized veins, and (2) to locate buried or obscured extensions of these fluorspar veins. The Northgate fluorspar deposits are among the largest in the western United States and have been commercially mined on a large scale since 1951. These deposits are being studied by Ronald G. Worl, U.S. Geological Survey, as part of an investigation of zoning in low-temperature barite, fluorite, and manganese oxide hydrothermal deposits. Of prime interest is the hypothesis that these deposits may form halos around adjacent base or precious metal deposits.
Colorado↗
Preliminary study of subsurface wastewater movement in and near Grand Teton National Park, Wyoming, through October 1976
Investigations were made by the U.S. Geological Survey in cooperation with Teton County, Wyoming and the National Park Service to determine the effects on nearby lakes and streams of percolating wastewater effluent at three sites in and near Grand Teton National Park. Observation wells were drilled at two of the sites, and water samples were collected from the wells. Sites were established on selected streams to collect water samples and to measure streamflow. Sufficient data have not been collected at this time to determine in detail the baseline quality of water in the selected streams or the rate, direction, and velocity of movement of percolating effluents. However, theoretical concepts and data collected to date suggest that effluent percolating near Colter Bay Village is most likely moving westward and southwestward toward Swan Lake and Colter Bay. Effluent percolating near Moose is most likely moving southeastward and southward toward the Snake River. Effluents near Flagg Ranch and Huckleberry Hot Springs probably discharge into the Snake River and Polecat Creek, but the amounts are small. (Woodard-USGS)
Open-File Report↗