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At least 1,081 records · Page 60Linked to original sources
USGS2006

Artificial Recharge — State of the Art

The largest potential reservoir for the storage of potable water is in the unsaturated zone. Use of this space for the storage and retrieval of potable water is a multifaceted problem which requires application of the best talent from the scientific community. Artificial recharge has many similarities to liquidwaste disposal through deep wells. In both, the problem is to place liquid in a permeable lithologic unit at an economic rate, to predict movement and the chemical reactions and physical changes that take place while the liquid is in the reservoir. Differences between the two operations are principally in the type of fluid injected and the ultimate objective. In artificial recharge the objective is to store and retrieve water of good quality; in waste disposal the objective is to store permanently water of objectionable quality. In both artificial recharge and liquid-waste storage, the nature of the storage must be known, particularly that of the unsaturated zone. The techniques of investigation for recharge and waste disposal are generally the same. Water commonly is recharged by surface spreading through basins or by induced recharge from adjacent streams and lakes or through injection wells. Research in recharge through basins has been dominated by mathematical models based on idealized conditions and empirical relations, derived by experimental sequencing of recharge operations, and operational controls in the pretreatment of recharge water. Recharge by injection wells has been undertaken in a variety of hydrologic environments. In Israel efforts have been directed toward the analyses of diffusion and dispersion of the injected water. Much research in the United States has been directed toward the movement of bacteria and organic matter through an aquifer and toward the chemical modeling of changes in recharged water as it moves. Much more research is needed on the basic properties of aquifers, particularly in the unsaturated zone, and on all aspects of recharge-water quality. Research and the use of data produced are increasingly the responsibility of interdisciplinary teams which consider the geologic, hydraulic, and economic aspects of the system.

Groundwater↗
USGS2001

Alaska: A twenty-first-century petroleum province

Alaska, the least explored of all United States regions, is estimated to contain approximately 40% of total U.S. undiscovered, technically recoverable oil and natural-gas resources, based on the most recent U.S. Department of the Interior (U.S. Geological Survey and Minerals Management Service) estimates. Northern Alaska, including the North Slope and adjacent Beaufort and Chukchi continental shelves, holds the lion's share of the total Alaskan endowment of more than 30 billion barrels (4.8 billion m 3 ) of oil and natural-gas liquids plus nearly 200 trillion cubic feet (5.7 trillion m 3 ) of natural gas. This geologically complex region includes prospective strata within passive-margin, rift, and foreland-basin sequences. Multiple source-rock zones have charged several regionally extensive petroleum systems. Extensional and compressional structures provide ample structural objectives. In addition, recent emphasis on stratigraphic traps has demonstrated significant resource potential in shelf and turbidite systems in Jurassic to Tertiary strata. Despite robust potential, northern Alaska remains a risky exploration frontier - a nexus of geologic complexity, harsh economic conditions, and volatile policy issues. Its role as a major petroleum province in this century will depend on continued technological innovations, not only in exploration and drilling operations, but also in development of huge, currently unmarketable natural-gas resources. Ultimately, policy decisions will determine whether exploration of arctic Alaska will proceed.

Alaska↗
USGS1967

Progress report: Ground-water appraisal of Cuyama Valley, California

Ground-water withdrawals in Cuyama Valley (fig. 1) have increased about 500 percent since the early forties, and since about 1947 annual withdrawal has exceeded the estimated perennial yield of the basin. This has caused a general decline of water levels in the valley, and a well-defined cone of depression about 2 by 6 miles in area, reflecting a maximum water-level decline of about 140 feet, has developed near Cuyama. Continued overdraft will increase pumping lifts until pumping costs are no longer economical. The U.S. Geological Survey, in cooperation with the Santa Barbara County Water Agency, has been engaged in a water-resources investigation of the area during the past year. Preliminary findings are summarized in this progress report, which has been prepared at the request of the Santa Barbara County Water Agency. Ground water in Cuyama Valley is replenished mostly by rain on a watershed of about 700 square miles (fig. 2). Most of that area, at altitudes from 2,000 to 5,000 feet above sea level, receives less than 14 inches of precipitation a year. Somewhat greater precipitation, about 24 to 30 inches, occurs in the headwater region of the Cuyama River and on the crest of the Sierra Madre Mountains, where altitudes exceed 7,000 feet. However, only a small part of the drainage from these highland areas reaches the Cuyama ground-water basin. In the valley itself the average annual rainfall is less than 10 inches. The average annual rainfall for the 21-year period (1945-65) at Cuyama is 5.79 inches (fig. 3). Most of the rain falls in winter and spring.

California↗
USGS2014

Porphyry copper assessment of western Central Asia

The U.S. Geological Survey conducted an assessment of resources associated with porphyry copper deposits in the western Central Asia countries of Kyrgyzstan, Uzbekistan, Kazakhstan, and Tajikistan and the southern Urals of Kazakhstan and Russia as part of a global mineral resource assessment. The purpose of the study was to (1) delineate permissive areas (tracts) for undiscovered porphyry copper deposits; (2) compile a database of known porphyry copper deposits and significant prospects; (3) where data permit, estimate numbers of undiscovered deposits within those permissive tracts; and (4) provide probabilistic estimates the amounts of copper (Cu), molybdenum (Mo), gold (Au), and silver (Ag) that could be contained in those undiscovered deposits. Western Central Asia, a region diverse in its geologic complexity, is situated north of the Tarim and North China tectonic blocks and sandwiched between the East European and Siberian cratons. The Ural Mountains form the western margin of the region; the southern margin is formed by the high-standing ranges that make up the Tian Shan mountain range in the border regions of Kazakhstan, Kyrgyzstan, and western China, where the effects of collisional tectonics are well displayed. The tectonic collage that makes up the core of western Central Asia is perhaps the geologically least understood part of the region. There is broad agreement that the early Paleozoic is made up of tectonically juxtaposed blocks that vary from Precambrian-cored microcontinents to magmatic arc and related complexes to subduction-related accretionary complexes. The rudiments of an incipient, contiguous single Kazakhstan block were formed by the end of the Silurian. In the middle to late Paleozoic, the block was unconformably superposed by two large, nested magmatic-arc belts, one Devonian, the other Carboniferous. Both magmatic-arc complexes were folded into a horseshoe-shaped, southeast-opening orocline in response to the final collisions of the various surrounding cratonic blocks with the Kazakhstan block. Additional deformation in the upper Cenozoic derived from the collision of India and China significantly redistributed fragments of the various mosaicked blocks, particularly in the central and southern parts of the western Central Asian region. Porphyry copper deposits are associated with many of the magmatic-arc fragments and belts throughout the geologically complex region, and economically important deposits are found in arc sequences of all Paleozoic Periods. The economically most productive arcs are Carboniferous. The assessment includes a discussion of the tectonic and geologic setting of porphyry copper deposits in western Central Asia (chapter 1), an application of remote sensing data for hydrothermal alteration mapping as a tool for porphyry copper assessment in the region (chapter 2), and a probabilistic assessment of undiscovered porphyry copper resources in four areas that represent Ordovician and Late Paleozoic (Carboniferous-Permian) magmatic arcs (chapter 3). The principal litho-tectonic terrane concept used to delineate permissive tracts was that of a magmatic arc that formed in the subduction boundary zone above a subducting plate. Eight permissive tracts are delineated on the basis of mapped and inferred subsurface distributions of igneous rocks assigned to magmatic arcs of specified age ranges that define areas where the occurrence of porphyry copper deposits within 1 kilometer of the Earth’s surface is possible. These tracts range in area from about 8,000 to 200,000 square kilometers and host 18 known porphyry copper deposits that contain about 54 million metric tons of copper. Available data included geologic maps, the distribution of significant porphyry copper occurrences and potentially related deposit types, the distribution of hydrothermal alteration patterns that are consistent with porphyry copper mineralization, and information on possible subsurface extensions of permissive rocks. On the basis of analyses of these data, the assessment team estimated a mean of 25 undiscovered porphyry copper deposits for the study area. Estimates of numbers of undiscovered deposits were combined with grade and tonnage models in a Monte Carlo simulation to yield a mean estimate of 95 million metric tons of copper in undiscovered porphyry copper deposits; this represents about twice the amount of identified porphyry copper resources (54 million metric tons). Detailed descriptions of each permissive tract, including the rationales for delineation and assessment, are given in appendixes, along with a geographic information system (GIS) that includes permissive tract boundaries, point locations of known porphyry copper deposits and significant occurrences, and hydrothermal alteration data based on analysis of remote sensing data.

Ural Mountains↗
USGS1975

Geological Survey and selected U.S. Bureau of Mines and Alaska Division of Geological and Geophysical Surveys reports and maps on Alaska released during 1974, indexed by quadrangle

All Geological Survey reports and maps on Alaska published or released to open files during 1974 are listed by the quadrangle (scale 1:250,000) into which Alaska has been divided for topographic mapping (p. 2). Also listed are U.S. Bureau of Mines reports on the geology and mineral resources of Alaska, but not those dealing exclusively with other subjects such as economics. Alaska Division of Geological and Geophysical Surveys published reports on geology and mineral resources are listed, but those released to open files are not. This is because all open-file reports and maps were withdrawn in 1974 for revision, consolidation, or assignment of new identification numbers before possible reissue. At the time of preparation of this index I had received so few newly released open-file reports that I felt that including any of them might cause confusion to potential users because of possible duplication of titles or numbers.

Alaska↗
USGS1976

Geological Survey and selected U.S. Bureau of Mines and Alaska Division of Geological and Geophysical Surveys reports and maps on Alaska released during 1975, indexed by quadrangle

All Geological Survey reports and maps on Alaska published or released to open files during 1975 are listed by the quadrangles (scale 1:250,000) into which Alaska has been divided for topographic mapping (p. 3). Also listed are U.S. Bureau of Mines reports on the geology and mineral resources of Alaska, but not those that deal exclusively with other subjects such as economics. Alaska Division of Geological and Geophysical Surveys published and open-filed reports and maps that were received by the Alaskan Geology Branch of the U.S. Geological Survey before March 1, 1976 are listed; the availability of several other reports and maps was publicly announced, but the documents were not available to me in time for them to be included here. Most of the reports and maps in this index bear a 1975 imprint date. Others bear earlier imprint dates, but were not released until 1975. All Alaska Division of Geological and Geophysical Surveys open-file reports and maps were withdrawn in 1974 for revision, consolidation, or assignment of new identification numbers. Those reissued reports and maps that I received before March 1, 1976 are listed in this index, no matter what imprint date they may bear. Also included are a few reports that were released before 1975, but hitherto had escaped my attention. Reports that deal with Alaska as a whole, with areas that can not be identified with a specific quadrangle, or that are mainly statistical presentations are listed under ALASKA - GENERAL, as are indexes and the like. Reports and maps that deal with offshore areas not within quadrangle boundaries are listed under OFFSHORE AREAS. The ALASKA - GENERAL and OFFSHORE AREAS lists appear before the alphabetically arranged quadrangle listings.

Alaska↗
USGS2009

Economics of undiscovered oil and gas in the North Slope of Alaska: Economic update and synthesis

The U.S. Geological Survey (USGS) has published assessments by geologists of undiscovered conventional oil and gas accumulations in the North Slope of Alaska; these assessments contain a set of scientifically based estimates of undiscovered, technically recoverable quantities of oil and gas in discrete oil and gas accumulations that can be produced with conventional recovery technology. The assessments do not incorporate economic factors such as recovery costs and product prices. The assessors considered undiscovered conventional oil and gas resources in four areas of the North Slope: (1) the central North Slope, (2) the National Petroleum Reserve in Alaska (NPRA), (3) the 1002 Area of the Arctic National Wildlife Refuge (ANWR), and (4) the area west of the NPRA, called in this report the 'western North Slope'. These analyses were prepared at different times with various minimum assessed oil and gas accumulation sizes and with slightly different assumptions. Results of these past studies were recently supplemented with information by the assessment geologists that allowed adjustments for uniform minimum assessed accumulation sizes and a consistent set of assumptions. The effort permitted the statistical aggregation of the assessments of the four areas composing the study area. This economic analysis is based on undiscovered assessed accumulation distributions represented by the four-area aggregation and incorporates updates of costs and technological and fiscal assumptions used in the initial economic analysis that accompanied the geologic assessment of each study area.

Alaska↗
USGS1946

Preliminary chemical correlation of chromite with the containing rocks

Chromite investigations of the U. S. Geological Survey since 1939 indicate that economic deposits of chromite rich in normative spinel ((Mg, Fe)Al 2 O 4 ) occur in peridotites which are closely associated with gabbro; high-chrome chromites occur in feldspar-free peridotites; and chromites rich in both normative chromite ((Mg, Fe)Cr 2 O 4 ) and magnetite (FeFe 2 O 4 ) are found in the pyroxene-rich stratiform complexes. Reaction of high-alumina chromite with diopsidic gabbro to form anorthite, olivine, and enstatite is described, and some probable equilibria between chromite and silicate minerals are discussed. A plot of 63 complete analyses on a triangular prism of composition shows that chromites from different geologic provinces in the Western Hemisphere vary consistently and fall in overlapping, but distinct, fields. The chromites of the Caribbean Province, which occur in dunite and troctolite, have the general formula Cr (sub 25-80) Al (sub 15-75) Fe (sub 1-5) (Mg (sub 65-75) ) and average about Cr 50 Al 47 (Mg 70 ). The chromites of the Pacific Coast, which occur in dunite and saxonite, average about Cr 70 Al 24 (Mg 60 ) in the range Cr (sub 60-77) Al (sub 16-35) Fe (sub 3-12) (Mg (sub 45-75) ). The stratiform deposits of the Stillwater and Bushveld complexes occur in harzburgite and bronzitite, and are very much alike, averaging Cr 60 Al 32 (Mg 52 ) and Cr 58 Al 34 (Mg 44 ) respectively. Chromites from gabbroic facies of the Bushveld complex are much richer in normative magnetite, presumably reflecting a higher CaO: Al 2 O 3 ratio in the silicate environment.

Economic Geology↗
USGS1979

Small-scale slump deposits, Middle Atlantic Continental Slope, off eastern United States

Analyses of 24 high-resolution seismic-reflection profiles that were collected during local and regional surveys show that small-scale slump deposite are ubiquitous whthin the intercanyon areas of the Continental Slope of the Middle Atlantic Bight. The deposits involve the upper 10-90 m of sediments, extend downslops for 1.8-7.2 km, and are present at water depths ranging from 545 to 1500 m. The characteristics of the deposits vary from thin, homogeneous or fairly regularly bedded lenses of sediment, to masses of intermediate thickness with contorted bedding, to relatively large slump blocks. A detailed survey of one slump mass just south of Hudson Canyon (by means of close-spaced Minisparker profiles and sediment cores) showed that it had a thickness of about 30 m and a volume of at least 0.4 km3 and consisted of homogeneous clay which accumulated rapidly during the late Pleistocene or Holocene. Although some of the slump deposits undoubtedly are relict, stemming from sediment instability porduced by rapid deposition during Pleistocene sea-level regressions, others were formed relatively recently. Possible causes of modern slumps include gas generation in the sediments, bottom-water turbulence on the upper slope, and shallow faulting. This study indicates that small-scale slumping in the intercanyon areas may be an important process in transporting sediments to the deep sea and suggests that recent mass movements may constitute a geologic hazard to future economic development of this part of the Continental Slope.

Middle Atlantic Bight↗
USGS1997

Estimating the social value of geologic map information: A regulatory application

People frequently regard the landscape as part of a static system. The mountains and rivers that cross the landscape, and the bedrock that supports the surface, change little during the course of a lifetime. Society can alter the geologic history of an area and, in so doing, affect the occurrence and impact of environmental hazards. For example, changes in land use can induce changes in erosion, sedimentation, and ground-water supply. As the environmental system is changed by both natural processes and human activities, the system's capacity to respond to additional stresses also changes. Information such as geologic maps describes the physical world and is critical for identifying solutions to land use and environmental issues. In this paper, a method is developed for estimating the economic value of applying geologic map information to siting a waste disposal facility. An improvement in geologic map information is shown to have a net positive value to society. Such maps enable planners to make superior land management decisions.

Journal of Environmental Economics and Management↗
USGS1907

Twenty-eighth annual report of the Director of the United States Geological Survey

The plan of operations for the last fiscal year, including an itemized statement of the appropriations, amounting to $1,758,720, with the allotments thereof, was approved by the Secretary of the Interior on July 10, 1906. The work of the various branches and divisions conformed to this plan, and a detailed statement of their operations may be found on later pages. On January 23 the former Director, Charles D. Walcott, was appointed to the position of Secretary of the Smithsonian Institution, and his resignation as Director was accepted by the President, becoming effective April 30, 1907. Mr. Walcott has been a member of the Survey since its organization, and the thirteen years of his service as the administrative head of the bureau cover the period of its greatest growth. At the beginning of his directorship Mr. Walcott disclaimed any desire to make radical changes in either the policy or the administration of the Survey as developed under his predecessors, King and Powell, but in his first report, the Director's sixteenth, he mentioned certain readjustments which he deemed desirable in order that the Survey might better meet the economic and educational needs of the country. It is noteworthy that, almost without exception, these improvements have been accomplished, and even more fully than as then outlined. Among these changes may be mentioned : The raising of the standard of the topographic maps, with the representation thereon of land subdivision lines, and the extension of exact leveling and primary triangulation; the placing of the entire topographic and geologic force within the classified service; the obtaining of authority from Congress to issue separates of the annual report in pamphlet form, thus permitting advance publication of chapters of the Mineral Resources report, as well as of papers on economic geology; the enlargement of the work of the divisions of hydrography, mineral resources, and geology, in the last case providing for reconnaissance surveys of regions of economic importance. Equally notable was the growth of the Survey under Mr. Walcott's administration, as shown by the increase in both the extent and the scope of its operations. The appropriations for the last fiscal year amounted to more than four times the total of those made thirteen years ago, and there was, of course, a corresponding increase in the amount of field and office work performed. The development of the relations between the Geological Survey and the public within the same period is measured by a more than fourfold increase in amount of official correspondence, nearly fourfold increase in number of printed pages in the various reports of the year, and a more than fivefold increase in copies of maps printed, while the total annual distribution of publications, books, and maps grew from less than 200,000 to nearly a million copies, the sales increasing from $2,100 to over $18,000. The extent to which the results of the work by this organization are now utilized by both the industrial world and the educational and scientific institutions furnishes the best index of the degree of success attained by Mr. Walcott and his colleagues.

Annual Report↗
USGS2002

Quality of economically extractable coal beds in the Gillette coal field as compared with other Tertiary coal beds in the Powder River basin, Wyoming and Montana

The Powder River Basin, and specifically the Gillette coal field, contains large quantities of economically extractable coal resources. These coal resources have low total sulfur content and ash yield, and most of the resources are subbituminous in rank. A recent U.S Geological Survey study of economically extractable coal in the Gillette coal field focused on five coal beds, the Wyodak rider, Upper Wyodak, Canyon, Lower Wyodak-Werner, and Gates/Kennedy. This report compares the coal quality of these economically extractable coal beds to coal in the Wyodak-Anderson coal zone in the Powder River Basin and in the Gillette coal field (Flores and others, 1999) and other produced coal in the Gillette coal field (Glass, 2000). The Upper Wyodak, Canyon, and Lower Wyodak/Werner beds are within the Wyodak-Anderson coal zone. Compared with all coal in the Wyodak-Anderson coal zone, both throughout the Powder River Basin and just within the Gillette coal field; the thick, persistent Upper Wyodak coal bed in the Gillette coal field has higher mean gross calorific value (8,569 Btu/lb), lower mean ash yield (5.8 percent), and lower mean total sulfur content (0.46 percent).

Open-File Report↗
USGS1981

Assessment of impacts of proposed coal-resource and related economic development on water resources, Yampa River basin, Colorado and Wyoming: A summary

Expanded mining and use of coal resources in the Rocky Mountain region of the western United States will have substantial impacts on water resources, environmental amenities, and social and economic conditions. The U.S. Geological Survey has completed a 3-year assessment of the Yampa River basin, Colorado and Wyoming, where increased coal-resource development has begun to affect the environment and quality of life. Economic projections of the overall effects of coal-resource development were used to estimate water use and the types and amounts of waste residuals that need to be assimilated into the environment. Based in part upon these projections, several physical-based models and other semiquantitative assessment methods were used to determine possible effects upon the basin's water resources. Depending on the magnitude of mining and use of coal resources in the basin, an estimated 0.7 to 2.7 million tons (0.6 to 2.4 million metric tons) of waste residuals may be discharged annually into the environment by coal-resource development and associated economic activities. If the assumed development of coal resources in the basin occurs, annual consumptive use of water, which was approximately 142,000 acre-feet (175 million cubic meters) during 1975, may almost double by 1990. In a related analysis of alternative cooling systems for coal-conversion facilities, four to five times as much water may be used consumptively in a wet-tower, cooling-pond recycling system as in once-through cooling. An equivalent amount of coal transported by slurry pipeline would require about one-third the water used consumptively by once-through cooling for in-basin conversion. Current conditions and a variety of possible changes in the water resources of the basin resulting from coal-resource development were assessed. Basin population may increase by as much as threefold between 1975 and 1990. Volumes of wastes requiring treatment will increase accordingly. Potential problems associated with ammonia-nitrogen concentrations in the Yampa River downstream from Steamboat Springs were evaluated using a waste-load assimilative-capacity model. Changes in sediment loads carried by streams due to increased coal mining and construction of roads and buildings may be apparent only locally; projected increases in sediment loads relative to historic loads from the basin are estimated to be 2 to 7 percent. Solid-waste residuals generated by coal-conversion processes and disposed of into old mine pits may cause widely dispersed ground-water contamination, based on simulation-modeling results. Projected increases in year-round water use will probably result in the construction of several proposed reservoirs. Current seasonal patterns of streamflow and of dissolvedsolids concentrations in streamflow will be altered appreciably by these reservoirs. Decreases in time-weighted mean-annual dissolved-solids concentrations of as much as 34 percent are anticipated, based upon model simulations of several configurations of proposed reservoirs. Detailed statistical analyses of water-quality conditions in the Yampa River basin were made. Regionalized maximum waterquality concentrations were estimated for possible comparison with future conditions. Using Landsat imagery and aerial photographs, potential remote-sensing applications were evaluated to monitor land-use changes and to assess both snow cover and turbidity levels in streams. The technical information provided by the several studies of the Yampa River basin assessment should be useful to regional planners and resource managers in evaluating the possible impacts of development on the basin's water resources.

Colorado, Wyoming↗
USGS2025

Cascading consequences and interventions for hazards after wildfire in Okanogan County, Washington

This report details the application of the chains of consequences method within the postfire hazard context after the 2021 Cedar Creek and Muckamuck Fires around Okanogan County, Washington. The U.S. Geological Survey Social and Economic Analysis branch convened 20 stakeholders with content- and context-specific knowledge related to these fires and their postfire hazards in an April 2023 Postfire Hazards Chains of Consequences Workshop. Guided by U.S. Geological Survey facilitators, workshop participants identified the cascading consequences of a specific postfire hazard scenario before brainstorming interventions to reduce the likelihood and severity of those consequences. The participants worked across disciplinary boundaries to identify gaps in understanding around cascading postfire hazard consequences and to brainstorm multidisciplinary interventions.

Washington↗
USGS1999

Environmental models of mineral deposits- A state of the art

Although mineral deposits have been classified by their geologic and mineralogical characteristics for decades, the recognition that mineral deposits also could be classified by their environmental characteristics is relatively new. In the past 5 years, numerous advancements have been made in this subject area, building on the earlier work of economic geologists who classified geologic characteristics. Several different approaches to understanding the environmental behavior of mineral deposits and associated altered areas have been taken, ranging from wholesale assessments of large areas (millions of km 2 ) to detailed assessments of individual watersheds or individual mines. While these first attempts have succeeded in describing some of the environmental characteristics of ore deposits in a number of ways, many important “environmental variables” are not included in present descriptive models. For example, the models should be expanded in scope to include a more thorough treatment of climatic and ecoregional effects- embodying such physical environmental characteristics as precipitation, evaporation, temperature, and ground water-surface water interactions. More complete model descriptions will have applications to the determination of baselines and natural backgrounds in mined and unmined areas, as well as possible anticipated effects of new mining in a given area, and mitigation and remediation strategies. The challenge to geologists and geochemists is to incorporate a widely disparate set of physical and chemical characteristics of mineralized and altered zones at scales ranging from microscopic (sub-millimeter) to macroscopic (10’s to 100’s of kilometers). This paper presents an overview of the development of mineral deposit environmental models, the current state of the art, an evaluation of needed improvements, and expected advancements in this field.

Geologica Hungarica. Series geologica↗
USGS1980

Geological Survey research 1980

A summary of recent significant scientific and economic results accompanied by a list of geologic, hydrologic, and cartographic investigations in progress.

Professional Paper↗
USGS1980

Outer Continental Shelf oil and gas activities in the Mid-Atlantic and their onshore impacts: a summary report, November 1979

Outer continental shelf (OCS) activity in the Mid-Atlantic Region to date has been limited to exploratory drilling. The first rig began drilling in March 1978. More rigs quickly moved into the Region, and as many as nine were working at the same time for a brief period in January 1979. As of November 1979, nineteen exploratory wells and two stratigraphic test wells had been drilled by the oil companies. One of these test wells and three exploratory wells have had shows of natural gas, but none of the oil companies has yet announced that it has found enough gas to go forward with plans for production. Because of the somewhat disappointing results so far, exploratory drilling has declined. Only one company is currently operating a rig, and one other company has announced plans to begin drilling this winter. The most recent risked estimates by the U.S. Geological Survey of undiscovered, economically recoverable oil and gas resources in the Mid-Atlantic tracts currently under lease are 8 million barrels of oil and 860 billion cubic feet of natural gas. The resource estimate for oil does not represent a commercially producible quantity. On the basis of the geologic information gained from wells completed to date and the huge capital costs of building a pipeline to bring the gas ashore, the natural gas estimate for currently leased tracts in the Mid-Atlantic Region appears to be short of a commercially producible amount. To date, onshore impacts resulting from OCS exploration consist of two support bases: a helicopter base in Atlantic City, New Jersey, from which crews are flown out to the drilling rigs; and a support base in Davisville, Rhode Island, from which equipment and supplies are ferried out to the rigs by boat. It is expected that exploratory activity will remain close to present levels for at least the next six months; consequently, support activity at Davisville and Atlantic City for Mid-Atlantic OCS operations during the same period is expected to correspond to current levels.

New Jersey;Rhode Island↗