Geology Reports⌕ Search

SEARCH · Geology Reports

Results for “Resources”

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 1,279 records · Page 71Linked to original sources
USGS2001

Petroleum geology and resources of the North Ustyurt Basin, Kazakhstan and Uzbekistan

The triangular-shaped North Ustyurt basin is located between the Caspian Sea and the Aral Lake in Kazakhstan and Uzbekistan and extends offshore both on the west and east. Along all its sides, the basin is bounded by the late Paleozoic and Triassic foldbelts that are partially overlain by Jurassic and younger rocks. The basin formed on a cratonic microcontinental block that was accreted northward to the Russian craton in Visean or Early Permian time. Continental collision and deformation along the southern and eastern basin margins occurred in Early Permian time. In Late Triassic time, the basin was subjected to strong compression that resulted in intrabasinal thrusting and faulting. Jurassic-Tertiary, mostly clastic rocks several hundred meters to 5 km thick overlie an older sequence of Devonian?Middle Carboniferous carbonates, Upper Precambrian massifs and deformed Caledonian foldbelts. The Carboniferous?Lower Permian clastics, carbonates, and volca-basement is at depths from 5.5 km on the highest uplifts to 11 nics, and Upper Permian?Triassic continental clastic rocks, pri-km in the deepest depressions. marily red beds. Paleogeographic conditions of sedimentation, Three total petroleum systems are identified in the basin. the distribution of rock types, and the thicknesses of pre-Triassic Combined volumes of discovered hydrocarbons in these sysstratigraphic units are poorly known because the rocks have been tems are nearly 2.4 billion barrels of oil and 2.4 trillion cubic penetrated by only a few wells in the western and eastern basin feet of gas. Almost all of the oil reserves are in the Buzachi Arch areas. The basement probably is heterogeneous; it includes and Surrounding Areas Composite Total Petroleum System in 2 Petroleum Geology, Resources?North Ustyurt Basin, Kazakhstan and Uzbekistan the western part of the basin. Oil pools are in shallow Jurassic and Neocomian sandstone reservoirs, in structural traps. Source rocks are absent in the total petroleum system area; therefore, the oil could have migrated from the adjacent North Caspian basin. The North Ustyurt Jurassic Total Petroleum System encompasses the rest of the basin area and includes Jurassic and younger rocks. Several oil and gas fields have been discovered in this total petroleum system. Oil accumulations are in Jurassic clastic reservoirs, in structural traps at depths of 2.5?3 km. Source rocks for the oil are lacustrine beds and coals in the continental Jurassic sequence. Gas fields are in shallow Eocene sandstones in the northern part of the total petroleum system. The origin of the gas is unknown. The North Ustyurt Paleozoic Total Petroleum System stratigraphically underlies the North Ustyurt Jurassic system and occupies the same geographic area. The total petroleum system is almost unexplored. Two commercial flows of gas and several oil and gas shows have been tested in Carboniferous shelf carbonates in the eastern part of the total petroleum system. Source rocks probably are adjacent Carboniferous deep-water facies interpreted from seismic data. The western extent of the total petroleum system is conjectural. Almost all exploration drilling in the North Ustyurt basin has been limited to Jurassic and younger targets. The underlying Paleozoic-Triassic sequence is poorly known and completely unexplored. No wells have been drilled in offshore parts of the basin. Each of three total petroleum systems was assessed as a single assessment unit. Undiscovered resources of the basin are small to moderate. Most of the undiscovered oil probably will be discovered in Jurassic and Neocomian stratigraphic and structural traps on the Buzachi arch, especially on its undrilled off-shore extension. Most of the gas discoveries are expected to be in Paleozoic carbonate reservoirs in the eastern part of the basin.

Bulletin↗
USGS2001

Petroleum geology and resources of the Baykit High province, East Siberia, Russia

The Baykit High province consists of two principal structural units?the Baykit regional high in the west, which occupies most of the province, and the Katanga structural saddle in the east. The province is on the western margin of the Siberian craton east of theYenisey Ridge foldbelt. The province is an exploration frontier and only a few prospects have been drilled. The oldest sedimentary rocks of the province, Riphean carbonate and clastic strata of Late Proterozoic age (1,650?650 million years old) that were deposited on the passive margin, cover the Archean?Lower Proterozoic basement. Basal Vendian (uppermost Proterozoic, 650?570 million years old) clastic rocks unconformably overlie various units of the Riphean and locally lie directly on the basement. Younger Vendian and lowermost Cambrian rocks are primarily dolomites. The Vendian/Cambrian boundary is con-formable, and its exact stratigraphic position has not been identified with certainty. The Lower Cambrian section is thick, and it consists of alternating beds of dolomite and evaporites (mostly salt). Middle and Upper Cambrian strata are composed of shale and dolomite. Ordovician-Silurian and upper Paleozoic rocks are thin, and they are present only in the northern areas of the province. Structural pattern of Riphean rocks differs substantially from that of Vendian-Cambrian rocks. A single total petroleum system (TPS) was identified in the Baykit High province. Discovered oil of the system is chiefly concentrated in Riphean carbonate reservoirs of the Yurubchen-Tokhom zone that is currently being explored and that has the Abstract 1 potential to become a giant field (or group of fields). The TPS also contains about 5 trillion cubic feet of discovered recover-able gas in clastic reservoir rocks at the base of the Vendian section. Petroleum source rocks are absent in the stratigraphic succession over most of the TPS area. Riphean organic-rich shales and carbonates that crop out in the Yenisey Ridge foldbelt west of the Baykit high are probable source rocks. Their areal distribution extends from the foldbelt into the foredeep along the province?s western margin. Potential source rocks also are present in platform depressions in eastern areas of the province. Hydrocarbon generation and migration west of the province started as early as Riphean time, before the beginning of the deformation in the Yenisey Ridge foldbelt that occurred about 820?850 million years ago. However, the presently known oil and gas accumulations were formed after deposition of the Lower Cambrian salt seal. Available data allow identification of only one assessment unit, and it covers the entire TPS area. Undiscovered oil and gas resources are moderate, primarily due to the poor quality of reservoir rocks. However, the reserve growth in the Yurubchen-Tokhom zone may be large and may exceed the volume of undiscovered resources in the rest of the province. Most oil and gas resourcesareexpectedtobeinstructuralandstratigraphictrapsin Riphean carbonate reservoirs. Vendian clastic reservoirs are probably gas-prone.

Bulletin↗
USGS2003

Petroleum geology and resources of the West Siberian Basin, Russia

The West Siberian basin is the largest petroleum basin in the world covering an area of about 2.2 million km2. The basin occupies a swampy plain between the Ural Mountains and the Yenisey River. On the north, the basin extends offshore into the southern Kara Sea. On the west, north, and east, the basin is surrounded by the Ural, Yenisey Ridge, and Turukhan-Igarka foldbelts that experienced major deformations during the Hercynian tectonic event and the Novaya Zemlya foldbelt that was deformed in early Cimmerian (Triassic) time. On the south, the folded Caledonian structures of the Central Kazakhstan and Altay-Sayan regions dip northward beneath the basin?s sedimentary cover. The basin is a relatively undeformed Mesozoic sag that overlies the Hercynian accreted terrane and the Early Triassic rift system. The basement is composed of foldbelts that were deformed in Late Carboniferous?Permian time during collision of the Siberian and Kazakhstan continents with the Russian craton. The basement also includes several microcontinental blocks with a relatively undeformed Paleozoic sedimentary sequence. The sedimentary succession of the basin is composed of Middle Triassic through Tertiary clastic rocks. The lower part of this succession is present only in the northern part of the basin; southward, progressively younger strata onlap the basement, so that in the southern areas the basement is overlain by Toarcian and younger rocks. The important stage in tectono-stratigraphic development of the basin was formation of a deep-water sea in Volgian?early Berriasian time. The sea covered more than one million km2 in the central basin area. Highly organic-rich siliceous shales of the Bazhenov Formation were deposited during this time in anoxic conditions on the sea bottom. Rocks of this formation have generated more than 80 percent of West Siberian oil reserves and probably a substantial part of its gas reserves. The deep-water basin was filled by prograding clastic clinoforms during Neocomian time. The clastic material was transported by a system of rivers dominantly from the eastern provenance. Sandstones within the Neocomian clinoforms contain the principal oil reservoirs. The thick continental Aptian?Cenomanian Pokur Formation above the Neocomian sequence contains giant gas reserves in the northern part of the basin. Three total petroleum systems are identified in the West Siberian basin. Volumes of discovered hydrocarbons in these systems are 144 billion barrels of oil and more than 1,300 trillion cubic feet of gas. The assessed mean undiscovered resources are 55.2 billion barrels of oil, 642.9 trillion cubic feet of gas, and 20.5 billion barrels of natural gas liquids. The largest known oil reserves are in the Bazhenov-Neocomian total petroleum system that includes Upper Jurassic and younger rocks of the central and southern parts of the basin. Oil reservoirs are mainly in Neocomian and Upper Jurassic clastic strata. Source rocks are organic-rich siliceous shales of the Bazhenov Formation. Most discovered reserves are in structural traps, but stratigraphic traps in the Neocomian clinoform sequence are pro-ductive and are expected to contain much of the undiscovered resources. Two assessment units are identified in this total petroleum system. The first assessment unit includes all conventional reservoirs in the stratigraphic interval from the Upper Jurassic to the Cenomanian. The second unit includes unconventional (or continuous), self-sourced, fractured reservoirs in the Bazhenov Formation. This unit was not assessed quantitatively. The Togur-Tyumen total petroleum system covers the same geographic area as the Bazhenov-Neocomian system, but it includes older, Lower?Middle Jurassic strata and weathered rocks at the top of the pre-Jurassic sequence. A Callovian regional shale seal of the Abalak and lower Vasyugan Formations separates the two systems. The Togur-Tyumen system is oil-prone; gas reserves are insignificant. The principal o

Bulletin↗
USGS2004

Petroleum geology and resources of the Amu-Darya basin, Turkmenistan, Uzbekistan, Afghanistan, and Iran

The Amu-Darya basin is a highly productive petroleum province in Turkmenistan and Uzbekistan (former Soviet Union), extending southwestward into Iran and southeastward into Afghanistan. The basin underlies deserts and semideserts north of the high ridges of the Kopet-Dag and Bande-Turkestan Mountains. On the northwest, the basin boundary crosses the crest of the Karakum regional structural high, and on the north the basin is bounded by the shallow basement of the Kyzylkum high. On the east, the Amu-Darya basin is separated by the buried southeast spur of the Gissar Range from the Afghan-Tajik basin, which is deformed into a series of north-south-trending synclinoria and anticlinoria. The separation of the two basins occurred during the Neogene Alpine orogeny; earlier, they were parts of a single sedimentary province. The basement of the Amu-Darya basin is a Hercynian accreted terrane composed of deformed and commonly metamorphosed Paleozoic rocks. These rocks are overlain by rift grabens filled with Upper Permian-Triassic rocks that are strongly compacted and diagenetically altered. This taphrogenic sequence, also considered to be a part of the economic basement, is overlain by thick Lower to Middle Jurassic, largely continental, coal-bearing rocks. The overlying Callovian-Oxfordian rocks are primarily carbonates. A deep-water basin surrounded by shallow shelves with reefs along their margins was formed during this time and reached its maximum topographic expression in the late Oxfordian. In Kimmeridgian-Tithonian time, the basin was filled with thick evaporites of the Gaurdak Formation. The Cretaceous-Paleogene sequence is composed chiefly of marine clastic rocks with carbonate intervals prominent in the Valanginian, Barremian, Maastrichtian, and Paleocene stratigraphic units. In Neogene time, the Alpine orogeny on the basin periphery resulted in deposition of continental clastics, initiation of new and rejuvenation of old faults, and formation of most structural traps. A single total petroleum system is identified in the Amu-Darya basin. The system is primarily gas prone. Discovered gas reserves are listed by Petroconsultants (1996) at about 230 trillion cubic feet, but recent discoveries and recent reserve estimates in older fields should increase this number by 40 to 50 trillion cubic feet. Reserves of liquid hydrocarbons (oil and condensate) are comparatively small, less than 2 billion barrels. Most of the gas reserves are concentrated in two stratigraphic intervals, Upper Jurassic carbonates and Neocomian clastics, each of which contains about one-half of the reserves. Reserves of other stratigraphic units?from Middle Jurassic to Paleogene in age?are relatively small. Source rocks for the gas are the Lower to Middle Jurassic clastics and coal and Oxfordian basinal black shales in the east-central part of the basin. The latter is probably responsible for the oil legs and much of the condensate in gas pools. Throughout most of the basin both source-rock units are presently in the gas-window zone. Traps are structural, paleogeomorphic, and stratigraphic, as well as a combination of these types. The giant Dauletabad field is in a combination trap with an essential hydrodynamic component. Four assessment units were identified in the total petroleum system. One unit in the northeastern, northern, and northwestern marginal areas of the basin and another in the southern marginal area are characterized by wide vertical distribution of hydrocarbon pools in Middle Jurassic to Paleocene rocks and the absence of the salt of the Gaurdak Formation. The other two assessment units are stratigraphically stacked; they occupy the central area of the basin and are separated by the regional undeformed salt seal of the Gaurdak Formation. The largest part of undiscovered hydrocarbon resources of the Amu-Darya basin is expected in older of these assessment units. The mean value of total assessed resources of the Amu-Darya basin is estimated

Bulletin↗
USGS1951

Water resources of southeastern Bucks County, Pennsylvania

This report has been prepared as a contribution to the development of southeastern Bucks County, Pa. It summarizes available information on the water resources of this 90-square mile area and evaluates current supplies. Future development of the area may change both the available quantity and the quality of the water supply. The effective development of the area demands a continuing knowledge of the water used and the potential quantity and quality of water available from both underground and surface sources. The area is strategically important to a great industrial section of the Bast. Its eastern boundary is a 26-mile segment of the Delaware River along the extreme southeastern border of Bucks County, Pa. (fig. 1). The present.population of the area is about 40,000, including 24,800 in Bristol Borough and Township and 6,770 in Morrisville. The area is traversed by both the Pennsylvania and the Reading Railroads and also by U.S. Highways 1 and 13. These are main transportation routes connecting the great market outlets of Philadelphia and New York. The Delaware River'is navigable from Morrisville to the sea. The area is only a short distance upstream from the Port of Philadelphia, which ranks second only to New York as the most important seaport in the United States. The area is mostly flat, open land 10 to 60 feet above mean sea level. It contains several large Industries, concentrated chiefly in the Bristol area (pi. 1). There are also scattered industries in the Morrisville, Langhorne, and Bensalem areas. However, Bucks County retains some of the characteristics of a farming region. Truck farming and gardening are still carried on to a considerable extent. Along Delaware River below Morrisville the mining of sand and gravel is an Important industry. The facts summarized in this report have been accumulated over a period of 25 years or more by Federal, State, and local agencies in connection with Investigations for other purposes. Most of the data used in this report have been obtained by the United States Geological Survey in cooperation with the Pennsylvania Department of Forests and Waters, the Pennsylvania Department of Internal Affairs, the Pennsylvania Department of Commerce, and State Planning Board, the City of Philadelphia, the Corps of Engineers, and the Interstate Commission on the Delaware River Basin. This report was prepared in the Water Resources Division of the U.S.Geological Survey by Jack B. Qraham, District Geologist; John W. Mangan, District Engineer; and Walter F. White, Jr., District Chemist, under the general direction of C. G. Paulsen, Chief Hydraulic Engineer.

Pennsylvania↗
USGS1997

1996 annual report on Alaska's mineral resources

This is the fifteenth annual report that has been prepared in response to the Alaska National Interest Lands Conservation Act. Current Alaskan mineral projects and events that occurred during 1995 are summarized. For the purpose of this document, the term 'minerals' encompasses both energy resources (oil and gas, coal and peat, uranium, and geothermal) and nonfuel-mineral resources (metallic and industrial minerals).

Circular↗
USGS1998

Economics and the 1995 National Assessment of United States Oil and Gas Resources

This report summarizes the economic component of the 1995 National Assessment of Oil and Gas Resources prepared by the U.S. Geological Survey for onshore and State offshore areas of the United States. Province and regional incremental cost functions for conventional undiscovered oil and gas fields, and selected unconventional oil and gas accumulations, allowing the ranking of areas by the incremental costs finding, developing, and producing these resources. Regional projections of additions to reserves from previously discovered fields to 2015 are also presented.

Circular↗
USGS2005

Water resources and the urban environment, lower Charles River watershed, Massachusetts, 1630-2005

The Charles River, one of the Nation’s most historically significant rivers, flows through the center of the Boston metropolitan region in eastern Massachusetts. The lower Charles River, downstream of the original head of tide in Watertown, was originally a productive estuary and important source of fish and shellfish for the Native Americans of the region. This portion of the river has an exceptionally long and colorful human history. In 1615, the explorer Captain John Smith gave the river its modern name, in honor of young Prince Charles of England. In 1617–18, the Native American community of the watershed was decimated by an epidemic, after having continuously occupied the area for the previous 4,000 years. In 1630, the first large group of English settlers, led by John Winthrop, set foot on the Shawmut Peninsula at the mouth of the river, and established the town of Boston. In the 1630s, the first printing press, public park, public school, and college in the English colonies were all established on the banks of the Charles River. Almost immediately, the settlers of Boston and adjacent towns also began to modify the landscape and water resources of the watershed. Perhaps the most important type of landscape alteration in the watershed was the filling of the extensive salt marshes and tidal flats of the estuary downstream of Watertown. This landmaking activity along the lower Charles River began in the mid-1600s, and did not conclude until the 1950s. In the early 20th century, the estuary mouth was dammed, creating a freshwater basin in the lower 9.5 miles of the river. A system of parks and parkways was built along the banks of the impounded river. In addition to the mainstem river, virtually all of the remaining water resources in the watershed have also been altered. Most of the river’s tributaries, for example, were culverted, or placed into tunnels, and many of the ponds and freshwater wetlands in the watershed were filled to facilitate urban development. One additional legacy of the river’s long human history is pollution from industry and sewage. By 1875, a total of 43 mills were operating along the lower Charles River between Watertown Dam and Boston Harbor. Thousands of gallons of untreated sewage and industrial wastewater entered the river daily through gravity drains, posing a major threat to public health. Concerted efforts to address the sewage problem began in the late 1870s. By the 1960s, the water quality of the river was significantly improved, yet still not suitable for swimming, fishing, or even boating under most conditions. In 1965, the Charles River Watershed Association was organized and the call to restore the environmental quality of the river and its parklands was heard anew. Passage of the Federal Clean Water Act in 1972 and the subsequent court-ordered reconstruction of the region’s sewage-treatment infrastructure in the 1980s and 1990s (the “Boston Harbor Cleanup”) provided additional impetus to address the river’s remaining pollution problems. In 1995, the U.S. Environmental Protection Agency launched the Clean Charles 2005 Initiative, which brought together government agencies, private-sector institutions, and environmental organizations to focus on restoring the river to fishable and swimmable conditions by Earth Day 2005. This initiative has achieved substantial improvements in water quality; sewage discharges to the river, for example, have been largely eliminated. Nevertheless, it is now widely acknowledged that full attainment of water-quality standards will likely depend upon improved public understanding of the watershed, continued efforts to eliminate illicit sewage discharges to the river, and better management of the urban runoff that enters the river both directly and from its many tributary streams.

Massachusetts↗
USGS2005

Marine mineral resources of Pacific Islands— A review of the Exclusive Economic Zones of islands of U.S. affiliation, excluding the State of Hawaii

The United States Exclusive Economic Zone (EEZ) was established in 1983 and comprises all marine areas within 200 nautical miles (370 kilometers) of the nearest U.S. land. This vast area of 3.38 million square nautical miles (11.6 million square kilometers) is about 20 percent greater than the entire land area of the United States. The resource potential of the vast mineral deposits that occur within the U.S. EEZ is unknown, despite field studies that have taken place during the past 25 years. Since about 1975, information on marine mineral deposits has been obtained by numerous research cruises to the Pacific Ocean by the U.S. Geological Survey (USGS), the U.S. National Oceanic and Atmospheric Administration (NOAA), equivalent government agencies in Germany, Canada, France, Russia, Japan, China, South Korea, Australia, and New Zealand, and by academic researchers from all of these nations. Although most of the cruises by other nations explored areas outside the U.S. EEZ, information gained from those studies can aid in the evaluation of the mineral potential in the U.S. EEZ. However, the global effort remains inadequate to allow for the quantitative evaluation of mineral resources contained within the EEZ of nations or within international regions of the oceans.

Circular↗
USGS2009

Thorium deposits of the United States — Energy resources for the future?

Many nations are exploring new ways to meet their growing energy supply needs, with a particular focus upon methods that produce lower carbon dioxide emissions compared to traditional oil, natural gas, and coal power plants. As a result, thorium-based nuclear power has experienced renewed attention as a potential energy source. Thus, it benefits the United States and other countries to identify and evaluate their indigenous thorium resources. This report describes the geology and resources of the principal thorium districts of the United States.

Circular↗
USGS2009

Hydrogeology and Groundwater Resources of the Coastal Aquifers of Southeastern Massachusetts

The glacially derived aquifer systems of southeastern Massachusetts compose the largest groundwater reservoir in the State. Population increases, land-use changes, and climate change in this area could lead to three primary environmental effects that relate directly to groundwater resources - (1) increases in pumping that could adversely affect environmentally sensitive groundwater-fed surface waters, such as ponds, streams, and wetlands; (2) changes in land use that could affect the quality of water in the aquifer; and (3) changes in precipitation and mean sea level that can affect water levels, streamflow, and the position of the freshwater/saltwater boundary. Therefore, understanding groundwater flow and the factors that can affect it is critical to managing and protecting this vital resource.

Circular↗
USGS2022

National assessment of carbon dioxide enhanced oil recovery and associated carbon dioxide retention resources — Results

In 2020, the U.S. Geological Survey (USGS) completed a probabilistic assessment of the volume of technically recoverable oil resources available if current carbon dioxide enhanced oil recovery (CO 2 -EOR) technologies were applied to amenable oil reservoirs underlying the onshore and State waters areas of the conterminous United States. The assessment also includes estimates of the mass of CO 2 that could be stored (retained) as a result of CO 2 -EOR activities. The USGS assessment team evaluated more than 3,500 oil reservoirs that were miscible to injected CO 2 . The assessed reservoirs are in 185 previously defined USGS plays in 33 petroleum provinces of 7 national regions. The assessment team estimated that the technically recoverable oil associated with CO 2 -EOR ranges from approximately 25,000 million barrels (MMbbl) at the P 5 percentile to as much as 32,000 MMbbl at the P 95 percentile, with a mean of 29,000 MMbbl. The associated CO 2 retention ranges from approximately 7,400 million metric tons (Mt) at the P 5 percentile to as much as 9,500 Mt at the P 95 percentile, with a mean of 8,400 Mt. The West Texas and Eastern New Mexico region and the Gulf Coast region together contain 60 percent of the mean assessed CO 2 -EOR oil potential and 61 percent of the mean assessed CO 2 retention. Other regions with significant resource potential include the Midcontinent region and Rocky Mountains and Northern Great Plains region.

Continental United States↗
USGS2022

Hydrologic data for water-management plans—A resource for Tribal Governments in Oklahoma

Introduction The major streams in Oklahoma, and the alluvial aquifers associated with those major streams, are important resources for the 39 federally recognized Tribes in Oklahoma. Many Tribal Governments are interested in developing water-management plans (hereinafter referred to as “water plans”) to preserve water resources for the future. This report provides a general overview of the types of information and data needed to prepare comprehensive water plans. To assist Tribes in the development of water plans, the U.S. Geological Survey, in cooperation with the Bureau of Indian Affairs, has outlined the steps necessary for creation of such plans.

Oklahoma↗
USGS2026

Coastal and Marine Hazards and Resources Program decadal science strategy 2020–2030

Overview The decadal science strategy of the Coastal and Marine Hazards and Resources Program (CMHRP) of the U.S. Geological Survey for 2020 to 2030 describes the CMHRP's vision and mission and the strategic framework needed to support key program goals: Conduct research and develop science-based tools that lead to safer, more productive coastal communities and improved stewardship of natural resources.

Circular↗
USGS1975

Assessment of geothermal resources of the United States, 1975

This assessment of geothermal resources of the United States consists of two major parts: (1) estimates of total heat in the ground to a depth of 10 km and (2) estimates of the part of this total heat that is recoverable with present technology, regardless of price. No attempt has been made to consider most aspects of the legal, environmental, and institutional limitations in exploiting these resouces. In general, the average heat content of rocks is considerably higher in the Western United States than in the East. This also helps to explain why the most favorable hydrothermal convection systems and the hot young igneous systems occur in the West. Resources of the most attractive identified convection systems (excluding national parks) with predicted reservoir temperatures above 150 deg C have an estimated electrical production potential of about 8,000 megawatt century, or about 26,000 megawatt for 30 years. Assumptions in this conversion are: (1) one-half of the volume of the heat reservoirs is porous and permeable, (2) one-half of the heat of the porous, permeable parts is recoverable in fluids at the wellheads, and (3) the conversion efficiency of heat in wellhead fluids to electricity ranges from about 8 to 20 percent , depending on temperature and kind of fluid (hot water or steam). The estimated overall efficiency of conversion of heat in the ground to electrical energy generally ranges from less than 2 to 5 percent, depending on type of system and reservoir temperature. (See also W77-07477)

Circular↗
USGS1980

Interactive computer methods for generating mineral-resource maps

Inasmuch as maps are a basic tool of geologists, the U.S. Geological Survey's CRIB (Computerized Resources Information Bank) was constructed so that the data it contains can be used to generate mineral-resource maps. However, by the standard methods used-batch processing and off-line plotting-the production of a finished map commonly takes 2-3 weeks. To produce computer-generated maps more rapidly, cheaply, and easily, and also to provide an effective demonstration tool, we have devised two related methods for plotting maps as alternatives to conventional batch methods. These methods are: 1. Quick-Plot, an interactive program whose output appears on a CRT (cathode-ray-tube) device, and 2. The Interactive CAM (Cartographic Automatic Mapping system), which combines batch and interactive runs. The output of the Interactive CAM system is final compilation (not camera-ready) paper copy. Both methods are designed to use data from the CRIB file in conjunction with a map-plotting program. Quick-Plot retrieves a user-selected subset of data from the CRIB file, immediately produces an image of the desired area on a CRT device, and plots data points according to a limited set of user-selected symbols. This method is useful for immediate evaluation of the map and for demonstrating how trial maps can be made quickly. The Interactive CAM system links the output of an interactive CRIB retrieval to a modified version of the CAM program, which runs in the batch mode and stores plotting instructions on a disk, rather than on a tape. The disk can be accessed by a CRT, and, thus, the user can view and evaluate the map output on a CRT immediately after a batch run, without waiting 1-3 days for an off-line plot. The user can, therefore, do most of the layout and design work in a relatively short time by use of the CRT, before generating a plot tape and having the map plotted on an off-line plotter.

Circular↗
USGS1983

Geothermal resources of southern Idaho

The geothermal resource of southern Idaho as assessed by the U.S. Geological Survey in 1978 is large. Most of the known hydrothermal systems in southern Idaho have calculated reservoir temperatures of less than 150?C. Water from many of these systems is valuable for direct heat applications, but is lower than the temperature of interest for commercial generation of electricity at the present time. Most of the known and inferred geothermal resources of southern Idaho underlie the Snake River Plain. However, major uncertainties exist concerning the geology and temperatures beneath the plain. By far the largest hydrothermal system in Idaho is in the Bruneau-Grand View area of the western Snake River Plain with a calculated reservoir temperature of 107?C and an energy of 4.5? 10 20 joules. No evidence of higher temperature water associated with this system has been found. Although the geology of the eastern Snake River Plain suggests that a large thermal anomaly may underlie this area of the plain, direct evidence of high temperatures has not been found. Large volumes of water at temperatures between 90? and 150?C probably exist along the margins of the Snake River Plain and in local areas north and south of the plain. Areas that appear particularly promising for the occurrence of large high-temperature hydrothermal systems are: the area north of the Snake River Plain and west of the Idaho batholith, the Island Park area, segments of the margins of the eastern Snake River Plain, and the Blackfoot lava field.

Circular↗
USGS1983

Petroleum geology and resources of the Volga-Ural province, U.S.S.R.

The Volga-Ural petroleum province is, in general, coincident with the Volga-Ural regional high, a broad upwarp of the east-central part of the Russian (East European) Platform. The central part of the province is occupied by the Tatar arch, which contains the major share of the oilfields of the province. The Komi-Perm arch forms the northeastern part of the regional high, and the Zhigulevsko-Pugachev and Orenburg arches make up the southern part. These arches are separated from one another by elongate downwarps. The platform cover overlies an Archean crystalline basement and consists of seven main sedimentation cycles. (1) Riphean (lower Bavly) continental sandstone, shale, and conglomerate beds, from 500 to 5,000 m thick, were deposited in aulacogens. (2) Vendian (upper Bavly) continental and marine shale and sandstone are up to 3,000 m thick. (3) Middle Devonian-Tournaisian transgressive deposits, which are sandstone, siltstone, and shale in the lower part and carbonates and abundant reefs in the upper part, range from 300 to 1,000 m in thickness. The upper carbonate part includes the Kamsko-Kinel trough system, which consists of narrow, interconnected, deepwater troughs. (4) The Visean-Namurian-Bashkirian cycle began with deposition of Visean clastic deposits, which draped over reefs of the previous cycle and filled in an erosional relief that had formed in some places on the sediments of the previous cycle. The Visean clastic deposits are overlain by marine carbonate beds. The cycle is from 50 to 800 m thick. (5) The lower Moscovian-Lower Permian cycle consists of 1,000 to 3,000 m of terrigenous clastic deposits and marine carbonate beds. (6) The upper Lower Permian-Upper Permian cycle reflects the maximum growth of the Ural Mountains and the associated Ural foredeep. Evaporite deposits were first laid down, followed by marine limestones and dolomites, which intertongue eastward with clastic sediments from the Ural Mountains. (7) Continental red beds of Triassic age and mixed continental and marine clastic beds of Jurassic and Cretaceous age were deposited on the western, southwestern, and northern margins of the Russian Platform; they are generally absent in the Volga-Ural province, however. Approximately 600 oilfields and gasfields and 2,000 pools have been found in the Volga-Ural province. Nine productive sequences are recognized; these are, in general, the same as the sedimentation cycles, although some subdivisions have been added. The clastic section of Middle and early Late Devonian age contains the major recoverable oil accumulations, including the supergiant Romashkino field. Cumulative production to 1980 is estimated at 30 to 35 billion barrels of oil equivalent, identified reserves at about 10 billion barrels of oil equivalent, and undiscovered resources at about 7 billion barrels of oil equivalent. Identified reserves of natural gas are estimated at 100 trillion cubic feet and undiscovered resources at 63 trillion cubic feet.

Circular↗