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USGS2019

Estimated 2016 groundwater level and drawdown from predevelopment to 2016 in the Santa Fe Group Aquifer System in the Albuquerque Area, Central New Mexico

The U.S. Geological Survey, in cooperation with the Albuquerque Bernalillo County Water Utility Authority (ABCWUA), has developed a series of maps and associated reports to document changes in the groundwater level in the production zone of the Santa Fe Group aquifer system in the Albuquerque, New Mexico, area. The current map and associated report document the construction of contours representing the groundwater-level surface of winter (November to March) conditions for water year 2016 and estimated net groundwater-level declines (called drawdown) since widespread groundwater pumping began in the early 1960s (called predevelopment conditions). Prior to 2008, groundwater withdrawal from the Santa Fe Group aquifer system was the principal water supply for the study area. The large quantity of withdrawal relative to recharge resulted in drawdown throughout the Albuquerque area. In response, the ABCWUA implemented a strategy for sustainable development of its water resources, including the diversion of surface water as part of the San Juan-Chama Drinking Water Project in 2008. The 2016 groundwater-level contours indicate that the general direction of groundwater flow is towards clusters of production wells in the eastern and northwestern parts of the study area. Drawdown from predevelopment to 2016 is greatest along the eastern margin of the study area and in the northwestern part of the study area, likely correlated with groundwater withdrawals and potentially compounded by proximity to faults. Comparing drawdown in water year 2016 to that of water years 2002, 2008, and 2012 shows a reduction in drawdown (groundwater-level rebound) in the study area since 2008, which corresponds with the timing of reductions in groundwater withdrawals as a result of the ABCWUA’s San Juan-Chama Drinking Water Project. Time-series analysis of groundwater-level measurements in piezometers within the study area also indicates the recent groundwater-level rebound since 2008.

New Mexico↗

USGS2019

Groundwater-level change for the periods 2002–8, 2008–12, and 2008–16 in the Santa Fe Group aquifer system in the Albuquerque area, central New Mexico

The U.S. Geological Survey, in cooperation with the Albuquerque Bernalillo County Water Utility Authority (ABCWUA), has developed a series of maps and associated reports, beginning in 2002, that document groundwater levels in the production zone of the Santa Fe Group aquifer system beneath a large area of the City of Albuquerque, New Mexico (hereafter called the study area). Herein, we document the construction of groundwater-level change maps for representative conditions during three periods: 2002–8, 2008–12, and 2008–16. Groundwater-elevation changes correspond to water use by the ABCWUA, with declines occurring prior to 2008 and accelerating recovery after 2008. Prior to 2008, the ABCWUA relied exclusively on groundwater from the Santa Fe Group aquifer system for municipal water supply. For the period 2002–8, near the end of the period of exclusive groundwater use, groundwater elevations in the production zone of the Santa Fe Group aquifer system declined as much as 20 to 30 feet. The largest 2002–8 groundwater-elevation declines were observed near the southeast corner of the study area and to the west of the Rio Grande. Since the ABCWUA implemented the San Juan-Chama Drinking Water Project in 2008, the proportion of municipal water supply sourced directly from surface water has increased to approximately two-thirds of the total water supply in 2016. Following initiation of this change in supply in 2008, groundwater elevations in the production zone of the Santa Fe Group aquifer system cumulatively rose as much as 20 to 30 feet by 2012 and 30 to 40 feet by 2016. The largest groundwater-elevation rises were observed near the northeast and southeast corners of the study area and to the west of the Rio Grande, whereas groundwater-elevation declines since 2008 were restricted to a localized area on the eastern margin of the study area. The area beneath the pre-flood-control-era (1971) flood plain of the Rio Grande underwent the least amount of groundwater-level change during any period, with minimal change prior to 2008 and small groundwater-elevation rises of less than 10 feet since 2008.

New Mexico↗

USGS2009

Digital Mapping Techniques '08: Workshop Proceedings, Moscow, Idaho, May 18-21, 2008

The Digital Mapping Techniques '08 (DMT'08) workshop was attended by more than 100 technical experts from 40 agencies, universities, and private companies, including representatives from 24 State geological surveys. This year's meeting, the twelfth in the annual series, was hosted by the Idaho Geological Survey, from May 18-21, 2008, on the University of Idaho campus in Moscow, Idaho. Each DMT workshop has been coordinated by the U.S. Geological Survey's National Geologic Map Database Project and the Association of American State Geologists (AASG). As in previous years' meetings, the objective was to foster informal discussion and exchange of technical information, principally in order to develop more efficient methods for digital mapping, cartography, GIS analysis, and information management. At this meeting, oral and poster presentations and special discussion sessions emphasized (1) methods for creating and publishing map products (here, "publishing" includes Web-based release); (2) field data capture software and techniques, including the use of LiDAR; (3) digital cartographic techniques; (4) migration of digital maps into ArcGIS Geodatabase format; (5) analytical GIS techniques; and (6) continued development of the National Geologic Map Database.

Open-File Report↗

USGS2006

Potentiometric surface of the Upper Floridan aquifer, west-central Florida, May 2005

The Floridan aquifer system consists of the Upper and Lower Floridan aquifers separated by the middle confining unit. The middle confining unit and the Lower Floridan aquifer in west-central Florida generally contain highly mineralized water. The water-bearing units containing freshwater are herein referred to as the Upper Floridan aquifer. The Upper Floridan aquifer is a highly productive aquifer and supplies more than 10 times the amount of water pumped from either the surficial aquifer system or the intermediate aquifer system in most of the study area (Duerr and others, 1988). This map report shows the potentiometric surface of the Upper Floridan aquifer measured in May 2005. The potentiometric surface is an imaginary surface connecting points of equal altitude to which water will rise in a tightly cased well that taps a confined aquifer system (Lohman, 1979). This map represents water-level conditions near the end of the dry season, when ground-water levels usually are at an annual low and withdrawals for agricultural use typically are high. The cumulative average rainfall of 67.27 inches for west-central Florida (from June 2004 through May 2005) was 14.20 inches above the historical cumulative average of 53.07 inches (Southwest Florida Water Management District (SWFWMD), 2005). The above average precipitation is attributed to the active hurrican season for Florida in 2004. Historical cumulative averages are calculated from regional rainfall summary reports (1915 to the most recent completed calendar year) and are updated monthly by the SWFWMD. This report, prepared by the U.S. Geological Survey (USGS) in cooperation with the SWFWMD, is part of a semiannual series of Upper Floridan aquifer potentiometric-surface map reports for west-central Florida. Potentiometric-surface maps have been prepared for January 1964, May 1969, May 1971, May 1973, May 1974, and for each May and September since 1975. Water-level data are collected in May and September each year to show the approximate annual low and high water-level conditions, respectively. Most of the water-level data for this map were collected by the USGS during May 23-27, 2005. Supplemental water-level data were collected by other agencies and companies. A corresponding potentiometric-surface map was prepared for areas east and north of the SWFWMD boundary by the USGS office in Altamonte Springs, Florida (Kinnaman, 2006). Most water-level measurements were made during a 5-day period; therefore, measurements do not represent a 'snapshot' of conditions at a specific time, nor do they necessarily coincide with the seasonal low water-level condition. Water levels in about 19 percent of the wells measured in May 2005 were lower than the May 2004 water levels (Blanchard and others, 2004). Data from 409 wells indicate that the May 2005 water levels ranged from about 5 feet below to about 18 feet above the May 2004 water levels (fig. 1). The largest water-level declines occurred in southwestern Hernando County, northeastern Hillsborough County, and parts of Hillsborough, Sumter, and Sarasota Counties. The largest water-level rises occurred in southeastern Hillsborough County, eastern Manatee County, and western Hardee County (fig. 1). Water levels in about 95 percent of the wells measured in May 2005 were lower than the September 2004 water levels (Blanchard and Seidenfeld, 2005). Data from 405 wells indicate that the May 2005 water levels ranged from about 22 feet below to 14 feet above the September 2004 water levels. The largest water-level decline was in east-central Manatee County and the largest water-level rise was in central Sarasota County.

Open-File Report↗

USGS2006

Preliminary surficial geologic map of a Calico Mountains piedmont and part of Coyote Lake, Mojave desert, San Bernardino County, California

This 1:24,000 scale detailed surficial geologic map and digital database of a Calico Mountains piedmont and part of Coyote Lake in south-central California depicts surficial deposits and generalized bedrock units. The mapping is part of a USGS project to investigate the spatial distribution of deposits linked to changes in climate, to provide framework geology for land use management (http://deserts.wr.usgs.gov), to understand the Quaternary tectonic history of the Mojave Desert, and to provide additional information on the history of Lake Manix, of which Coyote Lake is a sub-basin. Mapping is displayed on parts of four USGS 7.5 minute series topographic maps. The map area lies in the central Mojave Desert of California, northeast of Barstow, Calif. and south of Fort Irwin, Calif. and covers 258 sq.km. (99.5 sq.mi.). Geologic deposits in the area consist of Paleozoic metamorphic rocks, Mesozoic plutonic rocks, Miocene volcanic rocks, Pliocene-Pleistocene basin fill, and Quaternary surficial deposits. McCulloh (1960, 1965) conducted bedrock mapping and a generalized version of his maps are compiled into this map. McCulloh's maps contain many bedrock structures within the Calico Mountains that are not shown on the present map. This study resulted in several new findings, including the discovery of previously unrecognized faults, one of which is the Tin Can Alley fault. The north-striking Tin Can Alley fault is part of the Paradise fault zone (Miller and others, 2005), a potentially important feature for studying neo-tectonic strain in the Mojave Desert. Additionally, many Anodonta shells were collected in Coyote Lake lacustrine sediments for radiocarbon dating. Preliminary results support some of Meek's (1999) conclusions on the timing of Mojave River inflow into the Coyote Basin. The database includes information on geologic deposits, samples, and geochronology. The database is distributed in three parts: spatial map-based data, documentation, and printable map graphics of the database. Spatial data are distributed as an ArcInfo personal geodatabase, or as tabular data in the form of Microsoft Access Database (MDB) or dBase Format (DBF) file formats. Documentation includes this file, which provides a discussion of the surficial geology and describes the format and content of the map data, and Federal Geographic Data Committee (FGDC) metadata for the spatial map information. Map graphics files are distributed as Postscript and Adobe Acrobat Portable Document Format (PDF) files, and are appropriate for representing a view of the spatial database at the mapped scale.

Open-File Report↗

USGS2008

Digital Mapping Techniques '07 - Workshop Proceedings

The Digital Mapping Techniques '07 (DMT'07) workshop was attended by 85 technical experts from 49 agencies, universities, and private companies, including representatives from 27 state geological surveys. This year's meeting, the tenth in the annual series, was hosted by the South Carolina Geological Survey, from May 20-23, 2007, on the University of South Carolina campus in Columbia, South Carolina. Each DMT workshop has been coordinated by the U.S. Geological Survey's National Geologic Map Database Project and the Association of American State Geologists (AASG). As in previous year's meetings, the objective was to foster informal discussion and exchange of technical information, principally in order to develop more efficient methods for digital mapping, cartography, GIS analysis, and information management. At this meeting, oral and poster presentations and special discussion sessions emphasized: 1) methods for creating and publishing map products (here, 'publishing' includes Web-based release); 2) field data capture software and techniques, including the use of LIDAR; 3) digital cartographic techniques; 4) migration of digital maps into ArcGIS Geodatabase format; 5) analytical GIS techniques; and 6) continued development of the National Geologic Map Database.

Open-File Report↗

USGS1978

Geochemical and generalized geologic map showing distribution and abundance of molybdenum, copper, and lead in stream sediments in the Chandalar Quadrangle, Alaska

This geochemical map shows the distribution and abundance of molybdenum (Mo), copper (Cu), and lead (Pb) of -80 mesh (177 micrometers) stream sediment samples in the Chandalar quadrangle, Alaska. The map is a part of a series of geochemical maps that together with the background information circular (Reiser and others, 1978) comprise the folio on the Chandalar quadrangle, Alaska. The data are plotted on a subdued base map showing the generalized geology, topography, and sample localities. Map symbols showing the ranges of metal values are indicated on the accompanying histograms and all values shown are considered anomalous. An explanation of sampling, preparation, analytical procedures and geochemical raw data for all samples are discussed by O'Leary and others (1976). The -80 mesh (177 micrometers) stream sediment medium was used in this study because of the regional setting in the north-central Brooks Range. Given the rather restrictive time and manpower constraints the -80 mesh (177 micrometers) stream sediment combined with panned concentrates was determined to be the most economical and adequate medium in this case where clastic sediments are being derived from local bedrock. The study area is generally one of high relief with short fast-moving streams and broad glacial valleys. All samples were taken from active streams, as close to the center channel as possible. All sediments were considered to be locally derived. Care was taken, when sampling an obviously glaciated terrane, to sample above or upstream from morainal material, wherever possible. Most samples were taken in areas where bedrock was within 30 m of the sample site.

Alaska↗

USGS1971

Geohydrologic sections, Cache Valley, Utah and Idaho

This report was prepared as a part of a study of the ground-water resources of Cache Valley, Utah and Idaho. The study by the U.S. Geo- logical Survey was made during 1967-70 in cooperation with the Utah Department of Natural Resources, Division of Water Rights. The U.S. Bureau of Reclamation and the U.S. Soil Conservation Service cooperated by providing services; and counties, cities, irrigation districts, and some local organizations and businesses in both Utah and Idaho cooperated financially through the Utah Department of Natural Resources. In addition to this report, results of the study are presented in a basic-data release (McGreevy and Bjorklund, 1970) and in an interpretive report in preparation. Geologic and hydrologic data are combined and presented on a series of cross sections. Geologic contacts and faults or fault zones are based on indicated well logs, on the geologic map in the interpretive report (in preparation) , and on gravity data by Peterson and Oriel (1970).

Idaho, Utah↗

USGS2010

Hydrogeologic and geospatial data for the assessment of focused recharge to the carbonate-rock Aquifer in Genesee County, New York

Existing hydrogeologic and geospatial data useful for the assessment of focused recharge to the carbonate-rock aquifer in the central part of Genesee County, NY, were compiled from numerous local, State, and Federal agency sources. Data sources utilized in this pilot study include available geospatial datasets from Federal and State agencies, interviews with local highway departments and the Genesee County Soil and Water Conservation District, and an initial assessment of karst features through the analysis of ortho-photographs, with minimal field verification. The compiled information is presented in a series of county-wide and quadrangle maps. The county-wide maps present generalized hydrogeologic conditions including distribution of geologic units, major faults, and karst features, and bedrock-surface and water-table configurations. Ten sets of quadrangle maps of the area that overlies the carbonate-rock aquifer present more detailed and additional information including distribution of bedrock outcrops, thin and (or) permeable soils, and karst features such as sinkholes and swallets. Water-resource managers can utilize the information summarized in this report as a guide to their assessment of focused recharge to, and the potential for surface contaminants to reach the carbonate-rock aquifer.

New York↗

USGS2013

Geologic map of the Washougal quadrangle, Clark County, Washington, and Multnomah County, Oregon

The Washougal 7.5’ quadrangle spans the boundary between the Portland Basin and the Columbia River Gorge, approximately 30 km east of Portland, Oregon. The map area contains the westernmost portion of the Columbia River Gorge National Scenic area as well as the rapidly growing areas surrounding the Clark County, Washington, cities of Camas and Washougal. The Columbia River transects the map area, and two major tributaries, the Washougal River in Washington and the Sandy River in Oregon, also flow through the quadrangle. The Columbia, Washougal, and Sandy Rivers have all cut deep valleys through hilly uplands, exposing Oligocene volcanic bedrock in the north part of the map area and lava flows of the Miocene Columbia River Basalt Group in the western Columbia River Gorge. Elsewhere in the map area, these older rocks are buried beneath weakly consolidated to well-consolidated Neogene and younger basin-fill sedimentary rocks and Quaternary volcanic and sedimentary deposits. The Portland Basin is part of the Coastal Lowland that separates the Cascade Range from the Oregon Coast Range. The basin has been interpreted as a pull-apart basin located in the releasing stepover between two en echelon, northwest-striking, right-lateral fault zones. These fault zones are thought to reflect regional transpression, transtension, and dextral shear within the forearc in response to oblique subduction of the Pacific plate along the Cascadia Subduction Zone. The southwestern margin of the Portland Basin is a well-defined topographic break along the base of the Tualatin Mountains, an asymmetric anticlinal ridge that is bounded on its northeast flank by the Portland Hills Fault Zone, which is probably an active structure. The nature of the corresponding northeastern margin of the basin is less clear, but a series of poorly defined and partially buried dextral extensional structures has been hypothesized from topography, microseismicity, potential-field anomalies, and reconnaissance geologic mapping. This map is a contribution to a program designed to improve the geologic database for the Portland Basin region of the Pacific Northwest urban corridor, the densely populated Cascadia forearc region of western Washington and Oregon. Updated, more detailed information on the bedrock and surficial geology of the basin and its surrounding area will facilitate improved assessments of seismic risk, and resource availability in this rapidly growing region.

Oregon↗

USGS2014

Executive summary

Fossil fuels from the Appalachian basin region have been major contributors to the Nation’s energy needs over much of the last three centuries. Early records indicate that Appalachian coal was first mined in the middle 1700s (Virginia and Pennsylvania) and was used sparingly to fuel colonial settlements and, later, a fledgling industrial-based economy along the eastern seaboard of the United States (de Witt and Milici, 1989). In 2011, central Appalachian basin coal production accounted for approximately 77 percent of all U.S. metallurgical (or coking) coal and 29 percent of total U.S. production (U.S. Energy Information Administration, 2013). Following initial discoveries and commercial use in western New York (1821) and Ohio and West Virginia (mid-1830s), the Appalachian petroleum (oil and gas) industry began in earnest in 1859 with the discovery of oil at the Drake well in northwestern Pennsylvania. Between 1860 and 1989, the Appalachian basin produced more than 2.5 billion barrels of oil (BBO) and more than 30 trillion cubic feet of gas (TCFG) from more than 500,000 wells (de Witt and Milici, 1989). Although both oil and gas continue to be produced in the Appalachian basin, most new wells in the region are drilled in shale reservoirs to produce natural gas. Appalachian coal and petroleum resources are still available in sufficient quantities to contribute significantly to the Nation’s energy needs. For example, the U.S. Energy Information Administration (2010) estimated that there are 6,484 million short tons of recoverable coal reserves in the Appalachian basin. Similarly, about 14.7 billion barrels of oil equivalent (BBOE) (1.2 BBO+81 TCFG [or 13.5 BBOE]) of recoverable Appalachian basin oil and gas remain available of an estimated ultimate endowment of approximately 25.5 billion BBOE (cumulative production + reserves + estimated recoverable undiscovered resources) (this volume, chap. C.1). U.S. Geological Survey (USGS) Professional Paper 1708 is a modern, indepth collection of reports, cross sections, and maps that describe the geology of the Appalachian basin and its fossil fuel resources. Several of the chapters have been published in outside journals or as other USGS publications. Although this volume is not a comprehensive regional treatment of all notable geologic and fossil fuel localities in the Appalachian basin, the selected study areas and topics presented in the chapters cover large segments of the basin and a wide range of stratigraphic intervals. As the title implies, this volume addresses topics that refer to the locations of coal and petroleum accumulations, the stratigraphic and structural framework, and the geochemical characteristics of the coal beds and petroleum in the basin, as well as the results and documentation of recent USGS assessments of coal, oil, and gas resources in the basin. Many of the maps and accompanying data supporting the reports in this volume are available as downloadable geographic information system (GIS) data files (such as selected coal beds, selected oil and gas fields, locations of oil and gas wells, coal production, coal chemistry, total petroleum system (TPS) boundaries, and bedrock geology). Log ASCII Standard (LAS) files for geophysical (gamma ray) wireline well logs also are included. This publication supplements and updates older USGS regional studies of Appalachian basin coal and petroleum resources such as those by Arndt and others (1968) and the numerous contributors to USGS Miscellaneous Map Series I−917 (for example, Harris and others, 1978), respectively. USGS Professional Paper 1708 is intended primarily for geoscientists in academia, industry, and government who are interested in Appalachian basin geology and its coal and petroleum resources. Other users, however, may find the wide variety of topics, papers, and digital images of value for landuse and policy planning issues. Among the anticipated benefits of the report are improvements in (1) resource assessment estimates and methodology, (2) exploration strategies, (3) basin models, and (4) energy use policies.

Appalachian Basin↗

USGS2013

Metallogenic belt and mineral deposit maps of northeast Asia

This report contains explanatory material and summary tables for lode mineral deposits and placer districts (Map A, sheet 1) and metallogenic belts of Northeast Asia (Maps B, C, and D on sheets 2, 3, and 4, respectively). The map region includes eastern Siberia, southeastern Russia, Mongolia, northeast China, and Japan. A large group of geologists—members of the joint international project, Major Mineral Deposits, Metallogenesis, and Tectonics of Northeast Asia—prepared the maps, tables, and introductory text. This is a cooperative project with the Russian Academy of Sciences, Mongolian Academy of Sciences, Mongolian National University, Ulaanbaatar, Mongolian Technical University, Mineral Resources Authority of Mongolia, Geological Research Institute, Jilin University, China Geological Survey, Korea Institute of Geoscience and Mineral Resources, Geological Survey of Japan, and U.S. Geological Survey. This report is one of a series of reports on the mineral resources, geodynamics, and metallogenesis of Northeast Asia. Companion studies include (1) a detailed geodynamics map of Northeast Asia (Parfenov and others, 2003); (2) a compilation of major mineral deposit models (Rodionov and Nokleberg, 2000; Rodionov and others, 2000); (3) a series of metallogenic belt maps (Obolenskiy and others, 2004); (4) location map of lode mineral deposits and placer districts of Northeast Asia (Ariunbileg and others, 2003b); (5) descriptions of metallogenic belts (Rodionov and others, 2004); (6) a database on significant metalliferous and selected nonmetalliferous lode deposits and selected placer districts (Ariunbileg and others, 2003a); and (7) a series of summary project publications (Ariunbileg and 74 others, 2003b).

Asia↗

USGS1978

Geochemical and generalized geologic map showing distribution and abundance of barium, arsenic, boron, and vanadium in stream sediments in the Chandalar Quadrangle, Alaska

This geochemical map shows the distribution and abundance of barium (Ba), arsenic (As), boron (B), and vanadium (V) in -80 mesh (177 micrometers) stream sediment samples in the Chandalar quadrangle, Alaska. The map is a part of a series of geochemical maps that together with the background information circular (Reiser and others, 1978) comprise the folio on the Chandalar quadrangle, Alaska. The data are plotted on a subdued base map showing the generalized geology, topography, and sample localities. Map symbols showing the ranges of metal values are indicated on the accompanying histograms and all values shown are considered anomalous. An explanation of sampling, preparation, analytical procedures, and geochemical raw data for all samples are discussed by O'Leary and others (1976). The -80 mesh (177 micrometers) stream sediment medium was used in this study because of the regional setting in the north-central Brooks Range. Given the rather restrictive time and manpower constraints the -80 mesh (177 micrometers) stream sediment combined with panned concentrates was determined to be the most economical and adequate medium in this case where clastic sediments are being derived from local bedrock. The study area is generally one of high relief with short fast-moving streams and broad glacial valleys. All samples were taken from active streams, as close to the center channel as possible. All sediments were considered to be locally derived. Care was taken, when sampling an obviously glaciated terrane, to sample above or upstream from morainal material, wherever possible. Most samples were taken in areas where bedrock was within 30 m of the sample site. Due to the poor sensitivity by spectrographic analysis for arsenic, 200 ppm (parts per million), all arsenic analyses were done by colorimetry.

Alaska↗

USGS1979

Geochemical and generalized geologic map showing distribution and abundance of nickel, cobalt, lanthanum and yttrium in stream sediments, Chandalar 1° by 3° quadrangle, Alaska

This geochemical map shows the distribution and abundance of nickel (Ni), cobalt (Co), lanthanum (La), and yttrium (Y) in -80 mesh (177 micrometers) stream sediment samples in the Chandalar quadrangle, Alaska. The map is a part of a series of geochemical maps that together with the background information circular (Reiser and others, 1978) comprise the folio on the Chandalar quadrangle, Alaska. The data are plotted on a subdued base map showing the generalized geology, topography, and sample localities. Map symbols showing the ranges of metal values are indicated on the accompanying histograms and all values shown are considered anomalous. An explanation of sampling, preparation, and analytical procedures, and geochemical raw data for all samples are discussed by O'Leary and others (1976). The -80 mesh (177 micrometers) stream-sediment medium was used in this study because, given the rather restrictive time and manpower constraints, this medium combined with panned concentrates was determined to be the most economical and adequate medium in this area of the north-central Brooks Range where clastic sediments are derived from local bedrock. The study area is generally one of high relief with short fast moving streams and broad glacial valleys. All samples were taken from active streams, as close to the center channel as possible. All sediments were considered to be locally derived. Care was taken, when sampling an obviously glaciated terrane, to sample above or upstream from morainal material, wherever possible. Most samples were taken in areas where bedrock was within 30 m of the sample site.

Alaska↗

USGS2011

The U.S. Geological Survey mapping and cartographic database activities, 2006-2010

The U.S. Geological Survey (USGS) began systematic topographic mapping of the United States in the 1880s, beginning with scales of 1:250,000 and 1:125,000 in support of geological mapping. Responding to the need for higher resolution and more detail, the 1:62,500-scale, 15-minute, topographic map series was begun in the beginning of the 20th century. Finally, in the 1950s the USGS adopted the 1:24,000-scale, 7.5-minute topographic map series to portray even more detail, completing the coverage of the conterminous 48 states of the United States with this series in 1992. In 2001, the USGS developed the vision and concept of The National Map , a topographic database for the 21st century and the source for a new generation of topographic maps (http://nationalmap.gov/). In 2008, the initial production of those maps began with a 1:24,000-scale digital product. In a separate, but related project, the USGS began scanning the existing inventory of historical topographic maps at all scales to accompany the new topographic maps. The USGS also had developed a digital database of The National Atlas of the United States . The digital version of Atlas is now Web-available and supports a mapping engine for small scale maps of the United States and North America. These three efforts define topographic mapping activities of the USGS during the last few years and are discussed below.

Cartography and Geographic Information Science↗

USGS2007

Water-level and land-subsidence studies in the Mojave River and Morongo groundwater basins

Since 1992, the U.S. Geological Survey (USGS), in cooperation with the Mojave Water Agency (MWA), has constructed a series of regional water-table maps for intermittent years in a continuing effort to monitor groundwater conditions in the Mojave River and Morongo groundwater basins. The previously published data, which were used to construct these maps, can be accessed on the interactive map. The associated reports describing the groundwater conditions for the Mojave River groundwater basin for 1992 (Stamos and Predmore, 1995), the Morongo groundwater basin for 1994 (Trayler and Koczot, 1995), and for both groundwater basins for 1996 (Mendez and Christensen, 1997); for 1998 (Smith and Pimentel, 2000), for 2000 (Smith, 2002), for 2002 (Smith and others, 2004), for 2004 (Stamos and others, 2004), and for 2006 (Stamos and others, 2007) can be accessed using this web site. Spatially detailed maps of interferometric synthetic aperture radar (InSAR) methods were used to characterize land subsidence associated with groundwater-level declines during various intervals of time between 1992 and 1999 in the Mojave River and Morongo groundwater basins (Sneed and others, 2003). Concerns related to the potential for new or renewed land subsidence in the basins resulted in a cooperative study between the MWA and the USGS in 2006. InSAR data were developed to determine the location, extent, and magnitude of vertical land-surface changes in the Mojave River and Morongo groundwater basins for time intervals ranging from about 35 days to 14 months between 1999 and 2000 and between 2003 and 2004. (interactive Google map) The results from many future land-subsidence studies, which are scheduled about every 10 years, will be available on this website. Mapping of water-level contours, water-level change and numerous InSAR images were combined in an interactive map. This interactive map may be customized to your needs and viewed at a scale that is appropriate for the data.

California↗

USGS2011

Regional water table (2010) in the Mojave River and Morongo Groundwater basins, southwestern Mojave Desert, California

California↗

USGS2004

Geologic map of the Hasty Quadrangle, Boone and Newton Counties, Arkansas

This digital geologic map compilation presents new polygon (for example, geologic map unit contacts), line (for example, fault, fold axis, and structure contour), and point (for example, structural attitude, contact elevations) vector data for the Hasty 7.5-minute quadrangle in northern Arkansas. The map database, which is at 1:24,000-scale resolution, provides geologic coverage of an area of current hydrogeologic, tectonic, and stratigraphic interest. The Hasty quadrangle is located in northern Newton and southern Boone Counties about 20 km south of the town of Harrison. The map area is underlain by sedimentary rocks of Ordovician, Mississippian, and Pennsylvanian age that were mildly deformed by a series of normal and strike-slip faults and folds. The area is representative of the stratigraphic and structural setting of the southern Ozark Dome. The Hasty quadrangle map provides new geologic information for better understanding groundwater flow paths in and adjacent to the Buffalo River watershed.

Scientific Investigations Map↗