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At least 793 records · Page 44Linked to original sources
USGS2005

Influence of geologic setting on ground-water availability in the Lawrenceville area, Gwinnett County, Georgia

Obtaining large quantities of ground water needed for municipal and industrial supply in the Piedmont and Blue Ridge physiographic provinces can be challenging because of the complex geology and the typically low primary permeability of igneous and metamorphic rocks. Areas of enhanced secondary permeability in the bedrock do occur, however, and 'high-yield' wells are not uncommon, particularly where careful site-selection techniques are used prior to test drilling. The U.S. Geological Survey - in cooperation with the City of Lawrenceville, Georgia - conducted this study from 2000 to 2002 to learn more about how different geologic settings influence the availability of ground water in igneous and metamorphic bedrock with the expectation that this knowledge could be used to help identify additional water resources in the area. In compositionally layered-rock settings, wells derive water almost exclusively from lithologically and structurally controlled water-bearing zones formed parallel to foliation and compositional layering. These high-permeability, water-bearing zones - termed foliation-parallel parting systems -combined with high-angle joint systems, are the primary control for the high-yield wells drilled in the Lawrenceville area; yields range from 100 to several hundred gallons per minute (gal/min). Near Lawrenceville, areas with high ground-water yield are present in sequences of amphibolite, biotite gneiss, and button schist where the structural attitude of the rocks is gently dipping, in areas characterized by abundant jointing, and in topographic settings with a continuous source of recharge along these structures. In massive-rock settings, wells derive water mostly from joint systems, although foliation-parallel parting systems also may be important. Wells deriving water primarily from steeply-dipping joint systems typically have low yields ranging from 1 to 5 gal/min. Joint systems in massive-rock settings can be identified and characterized by using many of the methods described in this report. Geologic mapping was the primary method used to determine the distribution, variability, and relative concentrations (intensity) of joint systems. In the subsurface, joints were characterized by taking orientation measurements in the open boreholes of wells using acoustic and/or optical televiewers. In this investigation, the only practical approach found for locating areas of high ground-water potential was first through detailed geologic mapping followed by test drilling, borehole geophysical logging, and aquifer testing. Geologic methods help characterize both large- and small-scale structures and other lithologic and stratigraphic features that influence development of increased secondary permeability in the bedrock. The rock types, discontinuities, depth of weathering, topographic position, and recharge potential - which were the principal factors assessed through detailed geologic mapping - must be evaluated carefully, in relation to one another, to assess the ground-water potential in a given area.

Georgia↗
USGS2011

The shallow stratigraphy and sand resources offshore of the Mississippi Barrier Islands

Coastal Mississippi is protected by a series of barrier islands ranging in length from 10-25 kilometers that are less than 2 kilometers wide. The majority of these islands comprise the Gulf Islands National Seashore (GUIS), an ecologically diverse shoreline that provides habitat for wildlife including migratory birds and endangered animals. The majority of GUIS is submerged, and aquatic environments include dynamic tidal inlets, ebb-tide deltas, and seagrass beds. The islands are in a state of decline, with land areas severely reduced during the past century by storms, sea-level rise, and human alteration. Morton (2008) estimates that since the mid-1800s up to 64 percent of island surface area has been lost. Heavy damage was inflicted in 2005 by Hurricane Katrina, which passed by as a Category 3 storm and battered the islands with winds of more than 160 kilometers per hour and a storm surge up to 9 meters. Since 2007, the U.S. Geological Survey (USGS), in collaboration with the National Park Service, has been mapping the seafloor and substrate around the islands as part of the USGS Northern Gulf of Mexico Ecosystem Change and Hazard Susceptibility project. The purpose of these investigations is to characterize the near-surface stratigraphy and identify the influence it may have on island evolution and fate. In 2009, this effort provided the basis for a collaborative effort with the U.S. Army Corps of Engineers (USACE) to expand the investigation outside of GUIS boundaries as part of the Mississippi Coastal Improvement Project (MsCIP). The MsCIP program consists of structural, nonstructural, and environmental project elements to restore portions of coastal Mississippi and GUIS affected by storm impact. The project includes the placement of sand along the islands, both on the present beaches and within the littoral zone, to mitigate shoreline erosion and breaching. This action requires the location and assessment of offshore sand or sediment deposits that can provide suitable material for shoreline renourishment. The geophysical and sample information collected by the USGS during geologic investigations provides this information. As part of the MsCIP program, in March 2010 the USGS mapped approximately 300 square kilometers of seafloor around GUIS. Interferometric swath bathymetry, sidescan sonar, and Chirp sub-bottom profiling were used to characterize seafloor elevations, texture, and the underlying stratigraphy. On the basis of this information, potential sediment resources were identified. The most promising offshore deposits for beach restoration include shoals, lowstand valley fill, tidal delta deposits, abandoned barrier deposits, and dredge spoil. Of these, lowstand valley fill deposits and dredge spoil are less desirable; lowstand deposits are buried under a 2- to 4-meter blanket of mud, and dredge spoil volume is small. A relict tidal delta and submerged shoals are the most desirable deposits; the tidal delta contains a large volume of material still exposed on the seafloor, and parts of submerged shoals have modest volume and thin mud cover.

Mississippi↗
USGS1974

Map showing the thickness of loosely packed sediments and the depth to bedrock in the Sugar House quadrangle, Salt Lake County, Utah

This map provides information on the location and distribution of three general types of geologic materials in part of Salt Lake County, including the southeastern part of Salt Lake City, Utah. These materials have different physical properties that are pertinent to comprehensive planning and zoning, land-use studies, and engineering usage. The map should be of use in preliminary studies to determine the depth to different general types of foundation material and to determine the potential for settlement of the ground surface during major earthquakes, which could result in damage to waterlines, gaslines, large buildings, and other major engineering structures. The lines on the map are generalized. Lines showing the thickness of loosely packed sediments are based on drillers’ logs of 27 water wells in and near the 35-square-mile part of the quadrangle west of the mountains – less than one data point for each square mile. Lines showing the depth to bedrock are based on indirect geophysical data, and the data points are more widely scattered. The map may be useful as a general guide in planning, but investigations by qualified specialists should be made for detailed evaluations of specific areas. references to other reports of possible interest to the reader are included at the end of this text.

Utah↗
USGS1999

Alaska resource data file: McGrath quadrangle

The unnamed occurrence was investigated by the reporter in 1978 during a 1:63,360 scale geologic mapping effort for the Alaska Division of Geological and Geophysical Surveys in the McGrath quadrangle (Bundtzen and Laird, 1983). Two grab samples from the mineralized zone contained up to 222 ppm copper, 0.6 grams/tonne silver, and 100 ppm lead.

Alaska↗
USGS2004

A cross-site comparison of methods used for hydrogeologic characterization of the Galena-Platteville aquifer in Illinois and Wisconsin, with examples from selected Superfund sites

The effectiveness of 28 methods used to characterize the fractured Galena-Platteville aquifer at eight sites in northern Illinois and Wisconsin is evaluated. Analysis of government databases, previous investigations, topographic maps, aerial photographs, and outcrops was essential to understanding the hydrogeology in the area to be investigated. The effectiveness of surface-geophysical methods depended on site geology. Lithologic logging provided essential information for site characterization. Cores were used for stratigraphy and geotechnical analysis. Natural-gamma logging helped identify the effect of lithology on the location of secondary- permeability features. Caliper logging identified large secondary-permeability features. Neutron logs identified trends in matrix porosity. Acoustic-televiewer logs identified numerous secondary-permeability features and their orientation. Borehole-camera logs also identified a number of secondary-permeability features. Borehole ground-penetrating radar identified lithologic and secondary-permeability features. However, the accuracy and completeness of this method is uncertain. Single-point-resistance, density, and normal resistivity logs were of limited use. Water-level and water-quality data identified flow directions and indicated the horizontal and vertical distribution of aquifer permeability and the depth of the permeable features. Temperature, spontaneous potential, and fluid-resistivity logging identified few secondary-permeability features at some sites and several features at others. Flowmeter logging was the most effective geophysical method for characterizing secondary-permeability features. Aquifer tests provided insight into the permeability distribution, identified hydraulically interconnected features, the presence of heterogeneity and anisotropy, and determined effective porosity. Aquifer heterogeneity prevented calculation of accurate hydraulic properties from some tests. Different methods, such as flowmeter logging and slug testing, occasionally produced different interpretations. Aquifer characterization improved with an increase in the number of data points, the period of data collection, and the number of methods used.

Scientific Investigations Report↗
USGS2006

Geologic characteristics of benthic habitats in Glacier Bay, southeast Alaska

In April 2004, more than 40 hours of georeferenced submarine digital video was collected in water depths of 15-370 m in Glacier Bay to (1) ground-truth existing geophysical data (bathymetry and acoustic reflectance), (2) examine and record geologic characteristics of the sea floor, and (3) investigate the relation between substrate types and benthic communities, and (4) construct predictive maps of seafloor geomorphology and habitat distribution. Common substrates observed include rock, boulders, cobbles, rippled sand, bioturbated mud, and extensive beds of living horse mussels and scallops. Four principal sea-floor geomorphic types are distinguished by using video observations. Their distribution in lower and central Glacier Bay is predicted using a supervised, hierarchical decision-tree statistical classification of geophysical data.

Open-File Report↗
USGS2013

Challenges in making a seismic hazard map for Alaska and the Aleutians

We present a summary of the data and analyses leading to the revision of the time-independent probabilistic seismic hazard maps of Alaska and the Aleutians. These maps represent a revision of existing maps based on newly obtained data, and reflect best current judgments about methodology and approach. They have been prepared following the procedures and assumptions made in the preparation of the 2002 National Seismic Hazard Maps for the lower 48 States, and will be proposed for adoption in future revisions to the International Building Code. We present example maps for peak ground acceleration, 0.2 s spectral amplitude (SA), and 1.0 s SA at a probability level of 2% in 50 years (annual probability of 0.000404). In this summary, we emphasize issues encountered in preparation of the maps that motivate or require future investigation and research.

Alaska↗
USGS2024

Seabed maps showing topography, ruggedness, backscatter intensity, sediment mobility, and the distribution of geologic substrates in quadrangle 5 of the Stellwagen Bank National Marine Sanctuary region offshore of Boston, Massachusetts

The U.S. Geological Survey, in cooperation with the National Marine Sanctuary Program of the National Oceanic and Atmospheric Administration, has conducted seabed mapping and related research in the Stellwagen Bank National Marine Sanctuary (SBNMS) region since 1993. The area being mapped using geophysical and geological data includes the SBNMS and the surrounding region, which totals approximately 3,700 square kilometers (km 2 ) and is subdivided into 18 quadrangles. The seabed is a glaciated terrain that is topographically and texturally diverse. Quadrangle 5, the subject of this scientific investigations map, has an area of 211 km 2 and has water depths that range from 23 meters (m) on the Stellwagen Bank crest to 105 m in the Stellwagen Basin. Seven map types, each at a scale of 1:25,000, depict seabed topography, ruggedness, backscatter intensity, distribution of geologic substrates, sediment mobility, distribution of fine- and coarse-grained sand, and substrate mud content. These maps show the distribution of geologic substrates on the crest and western flank of the south-central part of Stellwagen Bank and in Stellwagen Basin to the west. Interpretations of multibeam sonar bathymetric and seabed backscatter imagery, photographs, video imagery, and grain-size analyses were used to create the geology-based maps. Data from 729 stations were analyzed, including 620 sediment samples. The geologic substrate maps of quadrangle 5 show the distribution of 20 substrates that represent a wide range of textures, such as mobile and rippled sand, immobile sand, sand that partially veneers gravel, boulder ridges, and mud. Mapped substrates are characterized by sediment grain-size composition, surface morphology, substrate layering, the mobility or immobility of substrate surfaces, and water depth range. This scientific investigations map portrays the major geological elements (substrates, topographic features, and processes) of environments in quadrangle 5. It is intended to provide a foundation for research into present and past sediment transport processes in a complex terrain, provide insights into the ecological requirements of invertebrate and vertebrate species that utilize the various substrates, and to support seabed management in the region.

Massachusetts↗
USGS2024

Seabed maps showing topography, ruggedness, backscatter intensity, sediment mobility, and the distribution of geologic substrates in quadrangle 2 of the Stellwagen Bank National Marine Sanctuary region offshore of Boston, Massachusetts

The U.S. Geological Survey, in cooperation with the National Marine Sanctuary Program of the National Oceanic and Atmospheric Administration, has conducted seabed mapping and related research in the Stellwagen Bank National Marine Sanctuary (SBNMS) region since 1993. The area being mapped using geophysical and geological data includes the SBNMS and the surrounding region, which totals approximately 3,700 square kilometers (km 2 ) and is subdivided into 18 quadrangles. The seabed is a glaciated terrain that is topographically and texturally diverse. Quadrangle 2, the subject of this scientific investigations map, has a mapped area of 209 km 2 and has water depths that range from about 19 meters (m) on the Stellwagen Bank crest to about 68 m in the Stellwagen Basin. Seven map types, each at a scale of 1:25,000, depict seabed topography, ruggedness, backscatter intensity, distribution of geologic substrates, sediment mobility, distribution of fine- and coarse-grained sand, and substrate mud content. These maps show the distribution of geologic substrates across the southwestern part of Stellwagen Bank, in Stellwagen Basin to the west and southwest of the bank, and in Little Stellwagen Basin and the western part of Race Point Channel to the south of the bank. Interpretations of multibeam sonar bathymetric and seabed backscatter imagery, photographs, video imagery, and grain-size analyses were used to create the geology-based maps. Data from 733 stations were analyzed, including 656 sediment samples. The geologic substrate maps of quadrangle 2 show the distribution of 19 geologic substrates that represent a wide range of textures, such as rippled and immobile sand, immobile muddy sand and sandy mud, sand that partially veneers gravel, and a boulder ridge. Mapped substrates are characterized by sediment grain-size composition, surface morphology, substrate layering, the mobility or immobility of substrate surfaces, and water depth range. This scientific investigations map portrays the major geological elements (substrates, topographic features, and processes) of environments in quadrangle 2. It is intended to provide a foundation for research into present and past sediment transport processes in a complex terrain, provide insights into the ecological requirements of invertebrate and vertebrate species that utilize the various substrates, and support seabed management in the region.

Massachusetts↗
USGS2026

Seabed maps showing topography, ruggedness, backscatter intensity, sediment mobility, and the distribution of geologic substrates in quadrangle 3 of the Stellwagen Bank National Marine Sanctuary region offshore of Boston, Massachusetts

The U.S. Geological Survey, in cooperation with the National Marine Sanctuary Program of the National Oceanic and Atmospheric Administration, has conducted seabed mapping and related research in the Stellwagen Bank National Marine Sanctuary (SBNMS) region since 1993. The area being mapped using geophysical and geological data includes the SBNMS and the surrounding region, which totals approximately 3,700 square kilometers (km 2 ) and is subdivided into 18 quadrangles. The seabed is a glaciated terrain that is topographically and texturally diverse. Quadrangle 3, the subject of this scientific investigations map, has a mapped area of 185 km 2 and has water depths that range from about 30 meters (m) on the Stellwagen Bank crest to about 135 m in a basin east of South Ninety Bank, which lies off the eastern margin of Stellwagen Bank. Seven map types, each at a scale of 1:25,000, depict seabed topography, ruggedness, backscatter intensity, distribution of geologic substrates, sediment mobility, distribution of fine- and coarse-grained sand, and substrate mud content. These maps show the distribution of geologic substrates on the southeastern part of Stellwagen Bank, on adjacent banks and basins in deeper water to the east, in the eastern part of Race Point Channel to the south of the bank, and on the northern slope of Cape Cod. Interpretations of multibeam sonar bathymetric and seabed backscatter imagery, photographs, video imagery, and grain-size analyses were used to create the geology-based maps. Data from 309 stations were analyzed, including 279 sediment samples. The geologic substrate maps of quadrangle 3 show the distribution of 21 geologic substrates that represent a wide range of textures, such as rippled sand, immobile sand, immobile muddy sand, sand that partially veneers gravel, and boulder ridges. Mapped substrates are characterized by sediment grain-size composition, surface morphology, substrate layering, the mobility or immobility of substrate surfaces, and water depth range. This scientific investigations map portrays the major geological elements (substrates, topographic features, and processes) of environments in quadrangle 3. It is intended to provide a foundation for research into present and past sediment transport processes in a complex terrain, provide insights into the ecological requirements of invertebrate and vertebrate species that use the various substrates, and support seabed management in the region.

Quadrangle 3 of the Stellwagen Bank National Marin↗
USGS1998

Geology, geochemistry, geophysics, mineral occurrences, and mineral resource assessment for the Commonwealth of Puerto Rico

The Commonwealth of Puerto Rico has been investigated over a very long period of time by earth scientists from many disciplines and with diverse objectives in the studies. This publication attempts to apply much of the geologic, geochemical, geophysical, and mineral occurrence information to a single objective focused on producing a mineral resource assessment for the Commonwealth of Puerto Rico. However, the value of this publication lies not within the results of the mineral resource assessment nor within the interactive PDF files which can be viewed on the screen, but within the geologic, geochemical, geophysical, and mineral occurrence digital map coverages and databases which can be used for their own unique applications. The mineral resource assessment of Puerto Rico represents compilation of several decades of mineral investigations and studies. These investigations have been the joint efforts of the U.S. Geological Survey, the Puerto Rico Department of Natural Resources, and the University of Puerto Rico. This report contains not only the mineral-resource assessment, but also much of the scientific evidence upon which the assessment was based.

Puerto Rico↗
USGS2012

Archive of digital chirp subbottom profile data collected during USGS cruise 10BIM04 offshore Cat Island, Mississippi, September 2010

In September of 2010, the U.S. Geological Survey (USGS), in cooperation with the U.S. Army Corps of Engineers (USACE), conducted a geophysical survey to investigate the geologic controls on barrier island framework of Cat Island, Miss., as part of a broader USGS study on Barrier Island Mapping (BIM). These surveys were funded through the Mississippi Coastal Improvements Program (MsCIP) and the Northern Gulf of Mexico (NGOM) Ecosystem Change and Hazard Susceptibility Project as part of the Holocene Coastal Evolution of the Mississippi-Alabama Region Subtask. This report serves as an archive of unprocessed digital chirp subbottom data, trackline maps, navigation files, GIS files, Field Activity Collection System (FACS) logs, and formal FGDC metadata. Gained (showing a relative increase in signal amplitude) digital images of the seismic profiles are also provided. Refer to the Acronyms page for expansions of acronyms and abbreviations used in this report. The USGS Saint Petersburg Coastal and Marine Science Center (SPCMSC) assigns a unique identifier to each cruise or field activity. For example, 10BIM04 tells us the data were collected in 2010 during the fourth field activity for that project in that calendar year. Refer to http://walrus.wr.usgs.gov/infobank/programs/html/definition/activity.html for a detailed description of the method used to assign the field activity identification (ID). All chirp systems use a signal of continuously varying frequency; the EdgeTech SB-512i system used during this survey produces high-resolution, shallow-penetration (typically less than 50 milliseconds (ms)) profile images of sub-seafloor stratigraphy. The towfish contains a transducer that transmits and receives acoustic energy; it was housed within a float system (built at the SPCMSC), which allows the towfish to be towed at a constant depth of 1.07 meters (m) below the sea surface. As transmitted acoustic energy intersects density boundaries, such as the seafloor or sub-surface sediment layers, some energy is reflected back toward the transducer, received, and recorded by a Personal Computer (PC)-based seismic acquisition system. This process is repeated at regular time intervals (for example, 0.125 seconds (s)), and returned energy is recorded for a specific duration (for example, 50 ms). In this way, a two-dimensional (2-D) vertical image of the shallow geologic structure beneath the ship track is produced. Figure 1 displays the acquisition geometry. Refer to table 1 for a summary of acquisition parameters and table 2 for trackline statistics. The archived trace data are in standard Society of Exploration Geophysicists (SEG) SEG Y rev. 0 format (Barry and others, 1975); the first 3,200 bytes of the card image header are in American Standard Code for Information Interchange (ASCII) format instead of Extended Binary Coded Decimal Interchange Code (EBCDIC) format. The SEG Y files may be downloaded and processed with commercial or public domain software such as Seismic Unix (SU) (Cohen and Stockwell, 2010). See the How To Download SEG Y Data page for download instructions. The printable profiles provided here are GIF images that were processed and gained using SU software, and they can be viewed from the Profiles page or from links located on the trackline maps; refer to the Software page for links to example SU processing scripts. The SEG Y files are available on the DVD version of this report or on the Web, downloadable via the USGS Coastal and Marine Geoscience Data System (http://cmgds.marine.usgs.gov). The data are also available for viewing using GeoMapApp (http://www.geomapapp.org) and Virtual Ocean (http://www.virtualocean.org) multi-platform open source software.

Mississippi↗
USGS1982

Geology of areas marked by geophysical anomalies (B-35 and B-34), Wadi Bidah District, Kingdom of Saudi Arabia

Geophysical surveys in the Wadi Bidah district, in the southwestern part of the Kingdom of Saudi Arabia, have revealed anomalies of the type that may be caused by deposits of massive sulfides. Accordingly, a study was undertaken to investigate the geologic environment associated with the geophysical anomalies and to determine whether mineral exploration of the anomalous areas might be warranted. An extensive geochemical sampling program did not disclose any evidence of ore mineral concentrations in the rocks. Detailed geologic mapping shows the anomalous areas to be underlain by Precambrian carbonaceous graywacke, the outcrop patterns of which closely fit the anomaly patterns. Field evidence and petrologic studies indicate that carbonaceous material in the rocks is the cause of the geophysical anomalies. Nothing was found in the anomalous areas that suggests the presence of mineral deposits of commercial grade, and further mineral investigations or exploration in the areas is not recommended.

Open-File Report↗
USGS2007

Integration of seafloor point data in usSEABED

Sediments of the beach, nearshore, and continental shelves record a complex interplay of processes including wave energy and direction , currents, beach erosion or accretion, bluff or cliff retreat, fluvial input, sediment longshore and cross-shelf transport processes, contaminant content and transport, sediment sources and sinks, and others. In turn, sediments and rocks modify wave patterns, affect recreation and tourism, and provide habitat for fish, epifauna, and infauna. Character of the surficial seafloor also influences navigation, commercial and recreational fishing and gathering of other food sources, communication, piplines, national defense, and provides geologic resources including sand and gravel aggregates, minerals, and real or potential energy sources. The beaches, nearshore, and continental margins fall under overlapping levels of managerial responsibility between Federal, State, regional, and local government agencies and consortia. In addition, universities and other academic institutions investigate these places for pure or applied scientific reasons. Mapping is usually the first step in understanding any issue and is often comprised of remotely gathered geophysical data such as bathymetry and backscatter imagery, and groundtruthing; that is, the collection of physical and virtual samples to tie the remotely gathered data to reality. The physical samples are described and (or) carefully analyzed for grain-size information -- which records both the site's physical conditions and geologic past -- and commonly, for constituent components such as mineral and rock types (to determine onland sources and in situ chemical processes), carbonate and organic content and microfossils (for biological and oceanographic influences), and structure such as layering and bioturbation (for physical influences). The samples may also be subjected to physical tests such as comp[action analyses, liquefaction or plasticity limits, ans other parameters important when considering construction of offshore structures. In recent years, virtual sampling of the seafloor has become popular, through the use of towed video or photographic equipment and the addition of camera to oceanographic equipment such as corers and tripods. Before about ten years ago, most maps were made by hand. Recently, with the advent of desktop GIS packages, map making and resource analysis can be done nearly "on-the-fly" if geographically located data exist. While the problems of projection, scale, and resolution of digitized paper maps are commonly known amongst GIS-users, access to the original underlying point data allows for maps to be regenerated for digital use using statistically proven methods, provides increasing data density by including multiple studies, as well as allows the point data to be used in other ways than just mapping. These point data may be available in raw or refined or in worded descriptions. Raw data such as granulometric analyses can be manipulated through the use of known equations or empirical relationships to provide information about other parameters of the sediment, such as mean grainsize, sorting, erodability, or rugosity. If refined data are presented such as gravel, sand, and mud percentages, the parameter noted earlier may be estimated. In the case of worded descriptions, values for geologic terms can be assigned, for example, "fine sand" equate to 0.2 mm sized particles, to provide numeric terms for GIS or modeling purposes.

Conference Paper↗
USGS2016

Developing integrated methods to address complex resource and environmental issues

Introduction This circular provides an overview of selected activities that were conducted within the U.S. Geological Survey (USGS) Integrated Methods Development Project, an interdisciplinary project designed to develop new tools and conduct innovative research requiring integration of geologic, geophysical, geochemical, and remote-sensing expertise. The project was supported by the USGS Mineral Resources Program, and its products and acquired capabilities have broad applications to missions throughout the USGS and beyond. In addressing challenges associated with understanding the location, quantity, and quality of mineral resources, and in investigating the potential environmental consequences of resource development, a number of field and laboratory capabilities and interpretative methodologies evolved from the project that have applications to traditional resource studies as well as to studies related to ecosystem health, human health, disaster and hazard assessment, and planetary science. New or improved tools and research findings developed within the project have been applied to other projects and activities. Specifically, geophysical equipment and techniques have been applied to a variety of traditional and nontraditional mineral- and energy-resource studies, military applications, environmental investigations, and applied research activities that involve climate change, mapping techniques, and monitoring capabilities. Diverse applied geochemistry activities provide a process-level understanding of the mobility, chemical speciation, and bioavailability of elements, particularly metals and metalloids, in a variety of environmental settings. Imaging spectroscopy capabilities maintained and developed within the project have been applied to traditional resource studies as well as to studies related to ecosystem health, human health, disaster assessment, and planetary science. Brief descriptions of capabilities and laboratory facilities and summaries of some applications of project products and research findings are included in this circular. The work helped support the USGS mission to “provide reliable scientific information to describe and understand the Earth; minimize loss of life and property from natural disasters; manage water, biological, energy, and mineral resources; and enhance and protect our quality of life.” Activities within the project include the following: Spanned scales from microscopic to planetary; Demonstrated broad applications across disciplines; Included life-cycle studies of mineral resources; Incorporated specialized areas of expertise in applied geochemistry including mineralogy, hydrogeology, analytical chemistry, aqueous geochemistry, biogeochemistry, microbiology, aquatic toxicology, and public health; and Incorporated specialized areas of expertise in geophysics including magnetics, gravity, radiometrics, electromagnetics, seismic, ground-penetrating radar, borehole radar, and imaging spectroscopy. This circular consists of eight sections that contain summaries of various activities under the project. The eight sections are listed below: Laboratory Facilities and Capabilities, which includes brief descriptions of the various types of laboratories and capabilities used for the project; Method and Software Development, which includes summaries of remote-sensing, geophysical, and mineralogical methods developed or enhanced by the project; Instrument Development, which includes descriptions of geophysical instruments developed under the project; Minerals, Energy, and Climate, which includes summaries of research that applies to mineral or energy resources, environmental processes and monitoring, and carbon sequestration by earth materials; Element Cycling, Toxicity, and Health, which includes summaries of several process-oriented geochemical and biogeochemical studies and health-related research activities; Hydrogeology and Water Quality, which includes descriptions of innovative geophysical, remote-sensing, and geochemical research pertaining to hydrogeology and water-quality applications; Hazards and Disaster Assessment, which includes summaries of research and method development that were applied to natural hazards, human-caused hazards, and disaster assessments; and Databases and Framework Studies, which includes descriptions of fundamental applications of geophysical studies and of the importance of archived data.

Circular↗
USGS2011

Science supporting Gulf of Mexico oil-spill response, mitigation, and restoration activities-Assessment, monitoring, mapping, and coordination

The St. Petersburg Coastal and Marine Science Center of the U.S. Geological Survey (USGS) investigates physical processes related to coastal and marine environments and societal implications related to natural hazards, resource sustainability, and environmental change. Immediately after the Deepwater Horizon event, the USGS began responding to data requests, directing response personnel, and providing coastal and shelf geophysical data to coastal-resource managers. The USGS provided oil-spill responders with up-to-date coastal bathymetry, geologic data, and maps characterizing vulnerability and levels of risk from potential spill impacts in Louisiana, Mississippi, and Alabama. Baseline conditions prior to any spill impacts were documented through programs that included shoreline sampling and sediment coring from east Texas to the east coast of Florida and aerial photography of many environmentally sensitive Gulf coastal areas. The USGS responded to numerous verbal and written data requests from Federal, State, and local partners and academic institutions with USGS scientific staff participating in the Coast Guard Unified Commands (UC) and Operational Science Advisory Teams (OSAT). The USGS conducted technical review of reports and plans for many response activities. Oil-spill responders, managers, and personnel on the ground, including partners such as the National Park Service, Gulf Islands National Seashore, Chandeleur Islands Refuge, and State agencies, continue to rely on USGS products.

General Information Product↗
USGS1985

Map showing the distribution of selected mineral assemblages in nonmagnetic heavy-mineral concentrates from stream sediments from the Vasquez Peak Wilderness Study Area, and the Williams Fork and St. Louis Peak Roadless Areas, Clear Creek, Grand, and Summit counties, Colorado

The U.S. Geological Survey and the U.S. Bureau of Mines conducted field studies from 1979 through 1983 to assess the mineral resource potential of the Vasquez Peak Wilderness Study Area (acreage: 16,000), the Williams Fork Roadless Area (acreage: 74,820), and the St. Louis Peak Roadless Area (acreage: 12,800). Included were geological, geochemical, and geophysical studies by the U.S. Geological Survey and investigation of known prospects and mines by the U.S. Bureau of Mines.

Colorado↗
USGS2025

Preliminary depth to basement modeling at Salton Sea, California

The San Andreas Fault – Imperial Fault (SAF-IF) transtensional step-over zone along the southern margin of the Salton Sea hosts substantial geothermal production and lithium brine resources. Recent volcanism at the Salton Buttes and active seismicity along the SAFIF fault system highlight active tectonic and magmatic processes that pose natural hazards and may impact energy and mineral production. Characterizing the subsurface architecture and extent of concealed alteration associated with this tectono-magmatic system enhances understanding of these active processes, associated hazards, and resources. We have compiled a gravity database, consisting of new and re-processed existing data, from which we have constructed a new isostatic residual gravity anomaly map of the Salton trough. We have used this new gravity dataset together with a compilation of publicly available borehole data to develop new depth to basement inversion models for the region. These depth to basement models help to constrain basin geometries, inform alteration mapping, and reveal variations in basement rocks. Due to the concealed nature of the complex tectonic framework at the Salton trough, it is necessary to utilize geophysical methods for subsurface characterization. These new depth to basement models are a first step toward constructing 2D and 3D geophysical and geologic models of the Imperial Valley and Salton Sea geothermal area. This analysis complements other geophysical initiatives, including magnetotelluric (MT) modeling (Tokmakoff et al., 2024), magnetic mapping (Glen and Earney, 2023, 2024) and potential field modeling, and seismic studies focused on hazard and resource investigations in the Imperial Valley.

California↗