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

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At least 55 records · Page 3Linked to original sources

Analysis of Egyptian Geological Survey and Mining Department samples by rapid rock and atomic absorption procedures

A suite of 165 samples from the Egyptian Geological Survey and Mining Department was analyzed for several elements in the Branch of Analytical Laboratories (BAL) of the U.S. Geological Survey by M. Iskander and S. Holyle during training here that focused on rapid-rock analytical procedures and on atomic-absorption spectrometric analyses. Because the training period was too brief to complete all required analyses on these samples, members of the BAL did additional determinations. These materials will serve as control samples when the newly learned techniques are implemented at the Cairo laboratory by M. Iskander and S. Holyle.

Open-File Report↗

The road to Yucca Mountain—Evolution of nuclear waste disposal in the United States

The generation of electricity by nuclear power and the manufacturing of atomic weapons have created a large amount of spent nuclear fuel and high-level radioactive waste. There is a world-wide consensus that the best way to protect mankind and the environment is to dispose of this waste in a deep geologic repository. Initial efforts focused on salt as the best medium for disposal, but the heat generated by the radioactive waste led many earth scientists to examine other rock types. In 1976, the director of the U.S. Geological Survey (USGS) wrote to the U.S. Energy Research and Development Administration (ERDA), predecessor agency of the U.S. Department of Energy (DOE), suggesting that there were several favorable environments at the Nevada Test Site (NTS), and that the USGS already had extensive background information on the NTS. Later, in a series of communications and one publication, the USGS espoused the favorability of the thick unsaturated zone. After the passage of the Nuclear Waste Policy Act (1982), the DOE compiled a list of nine favorable sites and settled on three to be characterized. In 1987, as the costs of characterizing three sites ballooned, Congress amended the Nuclear Waste Policy Act directing the DOE to focus only on Yucca Mountain in Nevada, with the proviso that if anything unfavorable was discovered, work would stop immediately. The U.S. DOE, the U.S. DOE national laboratories, and the USGS developed more than 100 detailed plans to study various earth-science aspects of Yucca Mountain and the surrounding area, as well as materials studies and engineering projects needed for a mined geologic repository. The work, which cost more than 10 billion dollars and required hundreds of man-years of work, culminated in a license application submitted to the U.S. Nuclear Regulatory Commission (NRC) in 2008.

Environmental & Engineering Geoscience↗

Seismicity and shear strain in the southern Great Basin of Nevada and California

This study examines the relationship between the distribution of small earthquakes (M L ≤4.3) and mechanisms of strain accumulation and relaxation in an area with long repeat times between large events, the Southern Great Basin Seismic Network (SGBSN) region. The Great Basin is a unique continental extensional province characterized by normal and strike-slip faulting, high heat flow, crust of thin to normal thickness, and high elevations. The SGBSN is operated to provide data to address suitability issues pertaining to Yucca Mountain, Nevada which is being evaluated as a potential site for a national mined geologic nuclear waste repository. Suitability issues include estimation of the probability of occurrence of future damaging earthquakes, the characterization of the mechanisms that drive hydrologic flow, and the identification of fractures (faults) that might act as flow conduits or barriers. This study attempts to explain the distribution of small earthquakes in terms of spatial variations in the shear strain field; where strain concentrates there should be a greater number of small earthquakes. Strain field models are constructed under the assumption that long term fault behavior perturbs an otherwise uniform strain field. These strain field models are then interpreted with regard to the regional tectonics and site suitability issues. Modeling results provide one possible explanation of why earthquake clusters cover regions much larger than the surface projections of any of mapped major faults; clusters in a wide band along and extending northeast of the northern half of the Furnace Creek fault may correspond to elevated shear strains along the fault and a broad cluster in the Pahranagat Shear Zone may be associated with shear strain arising from a distribution of smaller localized faults. The relatively large number of small earthquakes in the southern and eastern portions of the Nevada Test Site is consistent with the strain field models. A minimum in shear strain at Yucca Mountain is predicted by all models consistent with an almost total lack of earthquakes observed there. The region to the west of the Death Valley/Furnace Creek fault system, the portion of the study area with the most active deformation but few small earthquakes, is an area of low shear strain. A possible reason for this is that the fault configuration in the area is optimal for accommodating regional deformation via large earthquakes or creep. While there is also a relative lack of earthquakes at Yucca Mountain, this may be indicative of a lack of accumulating strain energy and thus, a lower potential for a large earthquake.

Journal of Geophysical Research↗

Memorandum describing the geology and ground-water conditions in the vicinity of Simpsonville, Maryland

This memorandum summarizes briefly the result of a study of the ground-water conditions of a small area near Simpsonville, Maryland, underlain chiefly by the Guilford granite (granite-pegmatite) of early Paleozoic or late Precambrian age. The records. of 15 wells and 5 sprints are given, as are t he sample-study legs of 3 test wells drilled at the site of a planned industrial labratory. A geologic map revised some-what from a published map by Cloos and Broedel is included (fig. 1). The study of the hydrology in the vicinity of Simpsonville was undertaken as a part of the ground-water investigations in cooperation with the Maryland Department of Geology, Mines and Water Resources. It provides ground-water data in addition to those already available, as a basis for a decision by the Maryland Water Resources Commission in regard to the application of an industrial laboratory to appropriate 200,000 gallons of ground water a day at a site about half a mile northwest of Simpsonville (approximately 12 miles southwest of Baltimore). Also, it supplements existing information on the occurrence of ground water in crystalline rocks of the type underlying the site, which are widespread in the Piedmont of Maryland and other States.

South Carolina↗

Simulated effects of increased recharge on the ground-water flow system of Yucca Mountain and vicinity, Nevada-California

A study was performed to assess the potential effects of changes in future climatic conditions on the groundwater system in the vicinity of Yucca Mountain, the site of a potential mined geologic repository for high-level nuclear wastes. These changes probably would result in greater rates of precipitation and, consequently, greater rates of recharge. The study was performed by simulating the groundwater system, using a two-dimensional, finite-element, groundwater flow model. The simulated position of the water table rose as much as 130 meters near the U.S. Department of Energy 's preferred repository area at Yucca Mountain for a simulation involving a 100-percent increase in precipitation compared to modern-day conditions. Despite the water table rise, no flooding of the potential repository would occur at its current proposed location. According to the simulation, springs would discharge south and west of Timber Mountain, along Fortymile Canyon, in the Amargosa Desert near Lathrop Wells and Franklin Lake playa, and near Furnace Creek Ranch in Death Valley, where they presently discharge. Simulated directions of groundwater flow paths near the potential repository area generally would be the same for the baseline (modern-day climate) and the increased-recharge simulations, but the magnitude of flow would increase by 2 to 4 times that of the baseline-simulation flow. (USGS)

California, Nevada↗

Assessment of fracture-sampling techniques for laboratory tests on core

As part of the site characterization work to be done at Yucca Mountain in Nye County, Nevada, a candidate site for the first mined-geologic repository for high-level nuclear waste, laboratory tests are proposed to evaluate fluid flow in single fractures. Laboratory and onsite tests were conducted to develop methods for collecting rock-core samples containing single fractures for the subsequent laboratory tests. Techniques for collecting rock cores with axial (parallel to the core axis) and radial (perpendicular to the core axis) fractures are discussed.

Conference Paper↗

Source-rock evaluation of outcrop samples from Vanuatu (Malakula, Espiritu Santo, Maewo, and Pentecost)

Thirty-nine outcrop samples of mudstones, siltstones, and limestones were collected for source-rock evaluation of the sedimentary column in Vanuatu. Twenty-nine samples showing the least evidence of oxidation were selected for total organic analysis from the Miocene Matanui Group and Port Sandwich Formation in Malakula, and from the Miocene Ilava, Peteao, and Pelapa Formations in Espiritu Santo. An additional 13 samples from the upper Miocene to Pleistocene sequence in the islands of Maewo and Pentecost were taken from the sample collection stored at the Department of Geology, Mines, and Rural WAter Supplies in Port Vila and analyzed for total organic carbon (T.O.C.). Of the 42 samples analyzed for total organic carbon content, four yielded values above the generally accepted minimum for source rock: three from the Peteao Formation (T.O.C. ranging from 0.52% to 1.44%), and one from the Pelapa Formation (T.O.C. = 0.54%). Rock-Eval pyrolysis on the rocks and reflected light microscopy on the separated organic matter indicate that the organic matter is poor in hydrogen and is dominantly type III kerogen; therefore, it is of a chemical type that does not yield liquid hydrocarbons but may havev limited potential for generating gas. The Rock-Eval pyrolysis and the vitrinite reflectance analysis indicate that the organic matter in these samples is thermally immature. The samples collected for the present study represent only a portion of the sedimentary column in the various sedimentary basins of Vanuatu. The characterize only the outer margins of the sedimentary basins and do not necessarily reflect the source-rock potential of the deeper (offshore) parts of the basins.

Book chapter↗

Geology of the Karamadazi iron mine, Kayseri Province, Turkey

A one-week underground geologic mapping program was conducted at the Karamadazi iron mine in order to describe the mine geology and obtain data that might help in the understanding of other similar deposits in Turkey. The Karamadazi mine is in a contact-metasomatic magnetite deposit 65 km. south-southwest of Kayseri, Turkey. The mine currently produces as much as 60,000 tons of iron ore per year containing approximately 60 percent iron. The mine is at a contact between granite and Permian and Carboniferous limestones. The limestones have been metamorphosed to marble and skarn, and the granite has a syenitic contact phase. The skarn has been partly replaced by massive magnetite ore and by minor quartz, calcite, and pyrite gangue. The main magnetite deposits are in a skarn zone 350-meters long by 20 to 70 meters wide that contains an estimated 40 percent magnetite in very irregular, steeply dipping ore bodies. Additional ore may be present under alluvial cover east of the mine; a magnetic survey of this area is recommended.

Kayseri Province↗

Lessons learned from the U.S. Geological Survey abandoned mine lands initiative: 1997-2002

Growth of the United States has been facilitated, in part, by hard-rock mining in the Rocky Mountains. Abandoned and inactive mines cause many significant environmental concerns in hundreds of watersheds. Those who have responsibility to address these environmental concerns must have a basic level of scientific information about mining and mine wastes in a watershed prior to initiating remediation activities. To demonstrate what information is needed and how to obtain that information, the U.S. Geological Survey implemented the Abandoned Mine Lands (AML) Initiative from 1997 to 2002 with demonstration studies in the Boulder River watershed in Montana and the Animas River watershed in Colorado. The AML Initiative included collection and analysis of geologic, hydrologic, geochemical, geophysical, and biological data. The synergy of this interdisciplinary analysis produced a perspective of the environmental concerns that could not have come from a single discipline. Two examples of these perspectives include (1) the combination of hydrological tracer techniques, structural geology, and geophysics help to understand the spatial distribution of loading to the streams in a way that cannot be evaluated by monitoring at a catchment outlet, and (2) the combination of toxicology and hydrology combine to illustrate that seasonal variability of toxicity conditions occurs. Lessons have been learned by listening to and collaborating with land-management agencies to understand their needs and by applying interdisciplinary methods to answer their questions.

Colorado, Montana↗

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↗

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↗

Predicting methane emissions and developing reduction strategies for a Central Appalachian Basin, USA, longwall mine through analysis and modeling of geology and degasification system performance

Coal mine methane is a safety concern in active mines due to explosion risk and an environmental concern due to the greenhouse gas (GHG) properties of methane emissions to the atmosphere. Depending on the mine design and operation, structural and stratigraphic characteristics of the geology, and the properties of coal beds affected by mining, a significant amount of methane can be released during coal extraction. These emissions may be low and uniform, but they also can be high and abrupt, if not captured by using pre- and post-mining methods of degasification or not controlled by ventilation during mining. Therefore, emissions should be monitored and predicted accurately for underground safety and GHG reduction. Ventilation and degasification systems should be designed accordingly by taking into account the mine geological properties and the degasification system's performance. This paper presents a comprehensive study to predict emissions and proposes alternatives to reduce emissions in a longwall mine extracting metallurgical coal from the Pocahontas No. 3 coal bed in Virginia (Central Appalachian Basin), USA. The work focused on mining activity in four adjacent panels through analysis and modeling of geology and evaluation of the performance of the methane control system. Results showed that the mine geology contained a significant amount of gas within and around the panel areas, which was controlled by utilizing different degasification methods besides ventilation during mining. The study showed that after pre-mining degasification using fractured vertical wells and in-seam horizontal wells, each panel potentially contained ∼19 MMscf and ∼ 2 MMscf of gas remaining to be handled by the gob gas ventholes (GGVs) and the ventilation, respectively, per acre of mining. It was shown that extending the pre-mining degasification duration of vertical wells by as much as 4 years or drilling more horizontal wells with closer spacing could significantly reduce ventilation and gob emissions during the mining of coal.

Kentucky, Virginia, West Virginia↗

Bibliography and index of the geology of the Creede mining district and vicinity

This bibliography and index of the geology of the Creede mining district and vicinity was prepared in support of the increased number of studies being conducted in conjunction with the proposed deep drilling program at Creede. It was our intent to include in this compilation all papers, abstracts, and maps which contribute any information pertaining to the geology of the Creede district. Thus, references range from papers dealing entirely with Creede to those which contain only a small amount of data relevant to some aspect of Creede geology. Even abstracts of talks, which were later published as papers, are included in an effort to be as complete as possible. We would appreciate any corrections or additions to this bibliography and index.

Open-File Report↗