USGS Science⌕ Search

SEARCH · USGS Science

Results for “Maryland Geological Survey Report of Investigations”

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

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

At least 19 recordsLinked to original sources
USGS2000

A strategy for a stream-gaging network in Maryland

Water is a keystone resource. In abundance, it supplies cities, industries, and agriculture. To maintain healthy natural and human ecosystems, water must not only be present in adequate quantity, but it must be of suitable quality for its intended use. Water quality depends on the amount, or load, of contaminants, both natural and anthropogenic, that it contains. Accurate assessment of these contaminants requires that the amount of water flowing in a stream or river be known. To quantify streamflow in a given stream or river and the variation of that flow through time, it must be measured by use of stream gages. Monitoring water flow is fundamental to managing and protecting water resources, and requires a collaborative effort by all interested parties, including Federal, State, and local government agencies.

Maryl↗
USGS1985

Hydrogeology, digital solute-transport simulation, and geochemistry of the Lower Cretaceous aquifer system near Baltimore, Maryland

This study was made to develop information on the hydrogeology and ground-water geochemistry of the Patuxent and Patapsco aquifers (Lower Cretaceous) near Baltimore, Maryland. This information is needed to evaluate the availability and chemical quality of water from these aquifers. The Patuxent aquifer unconformably overlies Lower Paleozoic and Precambrian basement rocks and consists primarily of medium- to coarse-grained quartz sand. Discontinuous lenses of gravel and silty clay are commonly interbedded with the sand-sized material. The Patuxent aquifer in this area attains a thickness of 250 feet and transmissivities range from 2,000 to 8,000 feet squared per day. The Patuxent is the most productive source of ground water in the Baltimore area. In 1982, approximately 11 million gallons of water per day was produced from this unit. Several cones of depression, ranging from 30 to 50 feet below sea level, have developed in response to this pumping stress. The Arundel Formation conformably overlies the Patuxent aquifer. The Arundel is composed predominantly of clay and ranges from 0 to 150 feet thick. The Arundel exhibits very low vertical hydraulic conductivities that are on the order of 10 -9 to 10 -11 feet per second. This unit acts as the upper confining bed of the Patuxent aquifer in much of the project area. The Patapsco aquifer unconformably overlies the Arundel Formation and is a medium- to fine-grained quartz sand. The Patapsco functions as a water-table aquifer in much of the project area. Although the Patapsco has been heavily pumped in the past, pumpage from that aquifer in Baltimore was negligible in 1982. Brackish-water contamination of the Patuxent and Patapsco aquifers has been a major water-quality problem since the early 1900's. The Patuxent aquifer presently (1982) contains a circular plume of brackish-water contamination about 5 miles in diameter. This plume is centered on the Harbor district and has enlarged measurably since 1945. The Patapsco aquifer has a smaller zone of brackish-water contamination that has decreased in size since 1945. Borehole data demonstrate that the Arundel Formation has been breached by Pleistocene river channels near the Harbor district. These erosional channels provide a conduit for brackish water to intrude into the Patuxent aquifer. A two-dimensional areal solute-transport model of the Patuxent aquifer was constructed. This model was designed to estimate the future movement of the brackish-water plume based on alternative scenarios of aquifer use. Model simulations suggest that the plume will remain relatively immobile if 1982 pumping patterns continue into the foreseeable future. However, increased pumpage in the Marley Neck peninsula could draw the plume to the southeast and increase contamination of the Fairfield area. The water quality of the Patuxent aquifer is extremely variable. Because of this variability, it is useful to divide the aquifer into three water-quality zones: Zone 1 -- This zone corresponds to the plume of brackish-water contamination. Zone 2 -- This zone exhibits evidence of urbanization-related contamination such as measurable concentrations of organic chemicals and elevated concentrations of trace elements and total organic carbon. Zone 3 -- Water composition in this zone is controlled exclusively by naturally occurring chemical processes. These processes are dominated by reactions involving dissolved iron. Near the outcrop area, oxidation of pyrite and lignite consumes dissolved oxygen and produces ledges of iron hydroxide-cemented sandstones and conglomerates. The predominant dissolved iron species in oxic water is Fe(OH) 2 + . Downgradient, the water becomes anoxic and sulfate reduction becomes an important process. The predominant dissolved iron species in anoxic water is Fe 2+ .

Maryland↗
USGS1982

Map showing the potentiometric surface of the Magothy Aquifer in southern Maryland, September 1982

A map was prepared that shows the potentiometric surface of the Magothy aquifer in southern Maryland in September 1982. The map is based on measurements from a network of 83 observation wells. The highest levels of the potentiometric surface, 57 and 58 feet above sea level, were measured near the outcrop-subcrop of the aquifer in topographically high areas of Anne Arundel and Prince Georges Counties. The potentiometric surface slopes to the southeast to about sea level along much of the western shore of the Chesapeake Bay. Three distinct and extensive cones of depression have developed in the potentiometric surface around the well fields of the Annapolis area, Waldorf area, and Chalk Point. Several square miles of each cone are below sea level, and in some areas at Chalk Point and Waldorf, the cone is more than 50 feet below sea level. The network of wells was developed as part of the cooperative program between the U.S. Geological Survey, the Maryland Geological Survey, and the Maryland Energy Administration. (USGS)

Water-Resources Investigations Report↗
USGS1996

Hydrogeologic, soil, and water-quality data for j-field, Aberdeen Proving Ground, Maryland, 1989-94

Disposal of chemical-warfare agents, munitions, and industrial chemicals in J-Field, Aberdeen Proving Ground, Maryland, has resulted in ground-water, surface-water, and soil contamination. This report presents data collected by the U.S. Geological Survey from Novembr 1989 through September 1994 as part of a remedial investigation of J-Field in response to the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA). Hydrogeologic data, soil-gas and soil-quality data, and water-qualtiy data are included.

Open-File Report↗
USGS1959

Progress report on the investigations of bauxite deposits in the eastern part of Kauai, Hawaii

Investigations of bauxite deposits on Kauai by the U. S. Geological Survey in cooperation with the State of Hawaii were begun July 1, 1959. The investigations, as planned, are to consist of two phases, each of two years duration. The geological investigations of the bauxite and associated rocks in the field and a considerable amount of chemical and mineralogical work in the laboratory are planned for completion during the first two years of the project. During this phase, a geologist and an assistant will be working on Kauai and geologists, mineralogists, and chemists will be analyzing and studying samples of the bauxite in laboratories of the Geological Survey at Beltsville, Maryland, and Washington, D. C. The work during the second phase of the investigations will be carried on at Beltsville and Washington and will consist of completion of chemical and mineralogical investigations, compilation of maps, analysis of field and laboratory data including determination of the size and quality of the bauxite deposits in the eastern part of Kauai, mineralogical research on bauxite samples, and preparation of a final geological report.

Hawaii↗
USGS2011

An evaluation of traditional and emerging remote sensing technologies for the detection of fugitive contamination at selected Superfund hazardous waste sites

This report represents a remote sensing research effort conducted by the U.S. Geological Survey in cooperation with the U.S. Environmental Protection Agency (EPA) for the EPA Office of Inspector General. The objective of this investigation was to explore the efficacy of remote sensing as a technology for postclosure monitoring of hazardous waste sites as defined under the Comprehensive Environmental Response Compensation and Liability Act of 1980 (Public Law 96-510, 42 U.S.C. §9601 et seq.), also known as \"Superfund.\" Five delisted Superfund sites in Maryland and Virginia were imaged with a hyperspectral sensor and visited for collection of soil, water, and spectral samples and inspection of general site conditions. This report evaluates traditional and hyperspectral imagery and field spectroscopic measurement techniques in the characterization and analysis of fugitive (anthropogenic, uncontrolled) contamination at previously remediated hazardous waste disposal sites.

Open-File Report↗
USGS1999

Index of hydrologic characteristics and data resources for the Gwynns Falls watershed, Baltimore County and Baltimore City, Maryland

The Gwynns Falls watershed has been selected as the primary study area for the Baltimore Ecosystem Study, as part of the National Science Foundation's Long-Term Ecological Research program. Because the Baltimore Ecosystem Study will be investigating long-term hydrologic changes in the Gwynns Falls watershed, a compilation of existing data resources for the watershed is necessary. This report discusses hydrologic characteristics and presents a compilation of historical data resources for the Gwynns Falls watershed. Tables are presented that list active and discontinued continuous-record streamflow-gaging stations, nontidal crest-stage partial-record stations, low-flow partial-record stations, and water-quality partial-record stations operated by the U.S. Geological Survey, Maryland-Delaware-D. C. District, in the Gwynns Falls watershed. Statistics regarding the number of inventoried ground-water wells in or bordering the Gwynns Falls watershed also are presented. A summary of additional data resources for the Gwynns Falls watershed is provided. This includes (1) an inventory of selected U.S. Geological Survey studies and reports that contain historical data or basin characteristics for streams in the watershed, (2) a listing of indirect flood-discharge measurements that have been made at several monitoring stations in the watershed, (3) a brief discussion of channel-stability and bridge-scour data collected by the U.S. Geological Survey in the watershed during 1990?95, (4) a listing of climatological data stations in the watershed and in the surrounding regional area, and (5) a listing of other selected reports that include data or information on the Gwynns Falls watershed.

Maryland↗
USGS1999

Ten years of studies on Maryland's inner Continental Margin and coastal bays

During the past ten years of the Association of American State Geologists-Mineral Management Service Continental Margins Program, the Maryland Geological Survey investigated the sedimentological, paleontological, stratigraphical and geophysical character of Maryland's inner continental shelf. Based on seismic records and sedimentological analyses completed during the first four years, a late Quaternary stratigraphic model was developed. Five distinct stratigraphic units were identified and described on the Maryland inner shelf. These units represent late Pleistocene interglacial deposits, the oldest of which corresponds to pre-Illinoian (oxygen-isotope stages 7 and/or 9) transgressive shelf sands. Overlying the Q1 unit, the Q2 unit is a 6-meter thick mud sequence of oxygen-isotope stage 5 (128-75 ka) age. Units Q3 and Q4 representing fluvial and leading edge estuarine deposits (oxygen-isotope stages 4, 3 and 2) filled numerous paleochannels that were incised into units Q2 and Q1. Modern trailing-edge transgressive shelf shoals (Unit Q5) discontinuously cap the sequence. The 5th and 6th years studies reported on the economic minerals of surficial and cored sediments. Vibracores collected off the Maryland's shelf during previous studies were analyzed for mineral types and abundances, weight percent of general size fractions, and heavy mineral (HM) content. Mineralogic maturity indices were compiled to correlate the THM and economic heavy minerals (EHM) abundances with position offshore, sediment type, and the indices themselves. For the 7th year, the Maryland Geological Survey re-examined geophysical records and lithological data originally collected by the Army Corps of Engineers to locate and assess beach fill borrow areas for the Ocean City Beach Replenishment Project. Data from 163 vibracores and over 300 kilometers of high-resolution seismic profile records collected off Ocean City, Maryland, supported the stratigraphic model developed by MGS during the first four years of the AASG-MMS program. The Maryland coastal bays became the focus of study during the 8th and 9th years during which seismic records, cores and surficial sediment were collected in Isle of Wight and Assawoman Bays. Shallow pretransgression surface was mapped, relating the existing streams to offshore paleochannels. The tenth year study focused on developing a repository for vibracores collected on Maryland's inner continental shelf.During the past ten years of the Association of American State Geologists-Mineral Management Service Continental Margins Program, the Maryland Geological Survey investigated the sedimentological, paleontological, stratigraphical and geophysical character of Maryland's inner continental shelf. Based on seismic records and sedimentological analysis completed during the first four years, a late quaternary stratigraphic model was developed. Five distinct stratigraphic units were identified and described on the Maryland inner shelf. These units represent late Pleistocene interglacial deposits, the oldest of which corresponds to pre-Illinoian transgressive shelf sands.

Marine Georesources and Geotechnology↗
USGS1997

Forum on Geologic mapping applications in the Washington-Baltimore urban area; proceedings; Reston, Virginia, April 23, 1997

The Forum on Geologic mapping applications in the Washington-Baltimore urban area was convened on April 23, 1997, at Reston, Virginia. The forum was cosponsored by the U.S. Geological Survey and the Maryland Geological Survey, with assistance from the Virginia Division of Mineral Resources. Spatial earth science information in the Washington-Baltimore area provides a scientific framework for environmental assessment, urban planning, and future resource and hazard investigations in this area of the Chesapeake Bay watershed, which has sustained three centuries of urban growth.

Circular↗
USGS2012

A science plan for a comprehensive assessment of water supply in the region underlain by fractured rock in Maryland

The fractured rock region of Maryland, which includes land areas north and west of the Interstate 95 corridor, is the source of water supply for approximately 4.4 million Marylanders, or approximately 76 percent of the State's population. Whereas hundreds of thousands of residents rely on wells (both domestic and community), millions rely on surface-water sources. In this region, land use, geology, topography, water withdrawals, impoundments, and other factors affect water-flow characteristics. The unconfined groundwater systems are closely interconnected with rivers and streams, and are affected by seasonal and climatic variations. During droughts, groundwater levels drop, thereby decreasing well yields, and in some cases, wells have gone dry. Low ground-water levels contribute to reduced streamflows, which in turn, can lead to reduced habitat for aquatic life. Increased demand, over-allocation, population growth, and climate change can affect the future sustainability of water supplies in the region of Maryland underlain by fractured rock. In response to recommendations of the 2008 Advisory Committee on the Management and Protection of the State's Water Resources report, the Maryland Department of the Environment's Water Supply Program, the Maryland Geological Survey, the Maryland Department of Natural Resources, Monitoring and Non-Tidal Assessment (MANTA) Division, and the U.S. Geological Survey have developed a science plan for a comprehensive assessment that will provide new scientific information, new data analysis, and new tools for the State to better manage water resources in the fractured rock region of Maryland. The science plan lays out five goals for the comprehensive assessment: (1) develop tools for the improved management and investigation of groundwater and surface-water resources; (2) characterize factors affecting reliable yields of individual groundwater and surface-water supplies; (3) investigate impacts on nearby water withdrawal users caused by groundwater and surface-water withdrawals; (4) assess the role of streamflow and water withdrawals on the ecological integrity of streams; and (5) improve understanding of the distribution of water-quality conditions in fractured rock aquifers. To accomplish these goals, accurate data collection, review, and analysis are needed, including the study of "Research Watersheds" that can provide detailed information about the potential effects that climate change and water withdrawals may have on groundwater, streamflow, and aquatic life. The assessment planning started in 2009 and is being conducted with close interagency coordination. A Fractured Rock Aquifer Information System is currently (2012) undergoing initial development. Other major tasks that will be performed include the development of work plans for each science goal, the estimation of daily streamflow at ungaged streams, and the design and implementation of Research Watersheds. Finally, scenarios will be modeled to evaluate current water allocation permitting methodologies, investigate effects on nearby water withdrawal users caused by groundwater and surface-water withdrawals, and assess the potential impacts of climate change on water resources. Desktop and Web-based tools will be developed in order to meet the diverse research needs of the assessment. These tools, including the Fractured Rock Aquifer Information System will be continuously improved during the assessment to store relevant groundwater and surface-water data in spatially referenced databases, estimate streamflows, locate higher-yielding wells, estimate the impacts of withdrawals on nearby users, and assess the cumulative impacts of withdrawals on the aquatic resource. Tools will be developed to serve the needs of many audiences, including water resource managers, water suppliers, planners, policymakers, and other scientific investigators.

Maryl↗
USGS2013

Hydrogeology and hydrologic conditions of the Northern Atlantic Coastal Plain aquifer System from Long Island, New York, to North Carolina

The seaward-dipping sedimentary wedge that underlies the Northern Atlantic Coastal Plain forms a complex groundwater system. This major source of water provides for public and domestic supply and serves as a vital source of freshwater for industrial and agricultural uses throughout the region. Population increases and land-use and climate changes, however, have led to competing demands for water. The regional response of the aquifer system to these stresses poses regional challenges for water-resources management at the State level because hydrologic effects often extend beyond State boundaries. In response to these challenges, the U.S. Geological Survey Groundwater Resources Program began a regional assessment of the groundwater availability of the Northern Atlantic Coastal Plain aquifer system in 2010. The initial phase of this investigation included a refinement of the hydrogeologic framework and an updated hydrologic budget of this aquifer system from the last regional aquifer system assessment completed by the U.S. Geological Survey in the 1980s. Refinements to the hydrogeologic framework include revision of the regional aquifer names to be more consistent with local names in New York, New Jersey, Delaware, Maryland, and Virginia, the primary States included in the study area. Other revisions to the framework include characterization of the aquifers of the regional Potomac aquifer system. The regional Potomac aquifer system is subdivided for this report into two regional aquifers. These aquifers include the single Potomac aquifer in Virginia and two aquifers in Maryland, Delaware, and New Jersey, where the Potomac aquifer system thickens within the Salisbury Embayment. The two regional aquifers making up the Potomac aquifer system include the Potomac-Patapsco aquifer and the underlying Potomac-Patuxent aquifer. The Potomac-Patuxent aquifer includes the Lower Potomac-Raritan-Magothy aquifer in southern New Jersey and the Patuxent aquifers in Delaware and Maryland. In northern New Jersey and on Long Island, New York, the PotomacPatuxent aquifer is absent, but the Late Cretaceous fluvialdeltaic aquifer that is laterally equivalent with the upper part of the Potomac Formation now is considered part of the regional Potomac-Patapsco aquifer. This aquifer includes the Middle Potomac-Raritan-Magothy aquifer in New Jersey and the Lloyd aquifer on Long Island. The name “Upper Potomac aquifer” has been removed as part of this regional framework revision. The local aquifer previously considered part of the Upper Potomac aquifer now are part of the regional Magothy aquifer. These units include the Upper Potomac-Raritan-Magothy aquifer in New Jersey, the Magothy aquifers on Long Island, Delaware, and Maryland, and the Virginia Beach aquifer in Virginia. Updates to the regional hydrologic budget include revised estimates of aquifer recharge, water use and streamflow data. Inflow to the aquifer system of about 20,000 million gallons per day (Mgal/d) includes 19,600 Mgal/d from recharge from precipitation, 200 Mgal/d of recharge from wastewater via onsite domestic septic systems, and 200 Mgal/d from the release of water from aquifer storage. Outflow from the aquifer system includes groundwater discharge to streams (11,900 Mgal/d), groundwater withdrawals (1,500 Mgal/d), and groundwater discharge to coastal waters (6,600 Mgal/d). A numerical modeling analysis is required to improve this hydrologic budget calculation and to forecast future changes in water levels and aquifer storage caused by groundwater withdrawals, land-use changes, and the effects of climate variability and change.

Delaware, Maryland, New Jersey, New York, North Ca↗
USGS2014

Regional seismic lines across the Rome trough and Allegheny Plateau of northern West Virginia, western Maryland, and southwestern West Virginia

This chapter is a re-release of U.S. Geological Survey Geologic Investigations Map I–2791, of the same title, by Kulander and Ryder (2005), which in printed form consists of two oversized sheets and an accompanying pamphlet. The digital version of this publication, however, is only available as the pamphlet and a collection of all the individual graphics that are found on the two sheets.

Appalachian basin, Rome Trough↗
USGS2007

Bankfull Regional Curves for Streams in the Non-Urban, Non-Tidal Coastal Plain Physiographic Province, Virginia and Maryland

Natural-channel design involves constructing a stream channel with the dimensions, slope, and plan-view pattern that would be expected to transport water and sediment and yet maintain habitat and aesthetics consistent with unimpaired reaches. The adequate description of channel geometry in unimpaired reaches often is an important component of natural-channel design projects and can be facilitated through empirical regression relations, or regional curves, relating bankfull geometry to drainage area. One-variable, ordinary least-squares regressions relating bankfull discharge, bankfull cross-sectional area, bankfull width, and bankfull mean depth to drainage area were developed based on data collected at 20 streamflow-gaging stations in Virginia and Maryland. These regional curves can be used to estimate the bankfull discharge and bankfull channel geometry when the drainage area of a watershed is known. Field data collected at the site for each streamflow-gaging station included one longitudinal profile of bankfull features and channel-bed slope, two riffle cross-section surveys of channel geometry, cross-section pebble counts, and one site sketch with photographs of the channel and bankfull features. The top of the bank was the bankfull feature most indicative of bankfull geometry. Field data were analyzed to determine bankfull cross-sectional area, bankfull width, bankfull mean depth, and D50- and D84-particle sizes for the two riffles at each site. The bankfull geometry from the 8 sites surveyed during this study represents the average of two riffle cross sections for each site, and the bankfull geometry from the 12 Maryland sites represents one cross section for each site. Regional curves developed for the 20 sites had coefficient of determination (R2) values of 0.945, 0.890, 0.871, and 0.793 for bankfull cross-sectional area, width, mean depth, and discharge, respectively. The regional curves represent conditions for streams with defined channels and bankfull features in Virginia and Maryland with drainage areas ranging from 0.28 to 113 square miles. All sites included in the development of the regional curves were located on streams with U.S. Geological Survey streamflow-gaging stations. These curves can be used to verify bankfull features identified in the field and bankfull stage for ungaged streams in non-urban areas.

Scientific Investigations Report↗