Book review: Discovery of Oyu Tolgoi: A case study of mineral and geological exploration
No abstract available.
Economic Geology↗
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Results for “Explorer”
Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.
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Workshop 4: Use of bulk standards in exploration geochemistry
[No abstract available]
Conference Paper↗
Tourmaline in Appalachian - Caledonian massive sulphide deposits and its exploration significance.
Tourmaline is a common gangue mineral in several types of stratabound mineral deposits, including some massive base-metal sulphide ores of the Appalachian - Caledonian orogen. It is most abundant (sometimes forming massive foliated tourmalinite) in sediment-hosted deposits, such as those at the Elizabeth Cu mine and the Ore Knob Cu mine (North Carolina, USA). Trace amounts of tourmaline occur associated with volcanic-hosted deposits in the Piedmont and New England and also in the Trondheim district. Tourmaline associated with the massive sulphide deposits are Mg- rich dravites with major- and trace-element compositions significantly different from schorl. It is suggested that the necessary B was produced by submarine exhalative processes as a part of the same hydrothermal system that deposited the ores. An abundance of dravite in non-evaporitic terrains is believed to indicate proximity to former subaqueous fumarolic centres.-R.A.H.
Transactions of the Institution of Mining and Meta↗
MAJOR SOURCE OF SIDE-LOOKING AIRBORNE RADAR IMAGERY FOR RESEARCH AND EXPLORATION: THE U. S. GEOLOGICAL SURVEY.
The US Geological Survey (USGS) instituted a program in 1980 to acquire side-looking airbore radar (SLAR) data and make these data readily available to the public in a mosaic format comparable to the USGS 1:250,000-scale topographic map series. The SLAR data are also available as strip images at an acquisition scale of 1:250,000 or 1:400,000 (depending on the acquisition system), as a variety of print products and indexes, and in a limited amount in digital form on computer compatible tapes. Three different commercial X-band (3-cm) systems were used to acquire the imagery for producing the mosaics.
Conference Paper↗
TRENDS IN BOREHOLE GEOPHYSICS FOR MINERAL EXPLORATION: ASSAYING AND REMOTE DETECTION.
Several borehole geophysical techniques have been developed in recent years. Assaying technique development has been concentrated on nuclear methods, with some progress being made on using electrical and magnetic properties for mineral identification. Adaptation of conventional surface geophysical techniques to the borehole for locating near-misses of mineralized zones has led to the development of borehole resistivity, electromagnetic (EM), gravity and magnetic methods to the borehole environment. This paper discusses some of the applications and pitfalls of these new techniques.
Conference Paper↗
Southeastern extension of the Lake Basin fault zone in south- central Montana: implications for coal and hydrocarbon exploration ( USA).
The Lake Basin fault zone consists mainly of en echelon NE-striking normal faults that have been interpreted to be surface expressions of left-lateral movement along a basement wrench fault. Information gathered from recent field mapping of coal beds and from shallow, closely-spaced drill holes resulted in detailed coal bed correlations, which revealed another linear zone of en echelon faulting directly on the extended trend of the Lake Basin fault zone. This faulted area, referred to as the Sarpy Creek area, is located 48 km E of Hardin, Montana. It is about 16 km long, 13 km wide, and contains 21 en echelon normal faults that have an average strike of N 63oE. We therefore extend the Lake Basin fault zone 32 km farther SE than previously mapped to include the Sarpy Creek area. The Ash Creek oil field, Wyoming, 97 km due S of the Sarpy Creek area, produces from faulted anticlinal structues that have been interpreted to be genetically related to the primary wrench-fault system known as the Nye-Bowler fault zone. The structural similarities between the Sarpy Creek area and the Ash Creek area indicate that the Sarpy Creek area is a possible site for hydrocarbon accumulation.-from Authors
Mountain Geologist↗
Recent exploration and development of geothermal energy resources in the Escalante desert region, Southwestern Utah
Development of geothermal resources in southwest Utah's Sevier thermal area continued in the early 1990s with expansion of existing power-generation facilities. Completion of the Bud L. Bonnett geothermal power plant at the Cove Fort-Sulphurdale geothermal area brought total power generation capacity of the facility to 13.5 MWe (gross). At Cove Fort-Sulphurdate, recent declines in steam pressures within the shallow, vapor-dominated part of the resource prompted field developers to complete additional geothermal supply wells into the deeper, liquid-dominated portion of the resource. At Roosevelt Hot Springs near Milford, Intermountain Geothermal Company completed an additional supply well for Utah Power and Light Company's single-flash, Blundell plant. with the increased geothermal fluid supply from the new well, the Blundell plant now produces about 26 MWe (gross). The authors conducted several geothermal resource studies in undeveloped thermal areas in southwest Utah. Previous studies at Newcastle revealed a well-defined, self-potential minimum coincident with the intersection of major faults and the center of the heatflow anomaly. A detailed self-potential survey at Wood's Ranch, an area in northwest Iron County where thermal water was encountered in shallow wells, revealed a large (5,900 ?? 2,950 feet [1,800 ?? 900 m]) northeast-oriented self-potential anomaly which possibly results from the flow of shallow thermal fluid. Chemical geothermometry applied to Wood's Ranch water samples suggest reservoir temperatures between 230 and 248??F (110 and 120??C). At the Thermo Hot Springs geothermal area near Minersville, detailed self-potential surveys have also revealed an interesting 100 mV negative anomaly possibly related to the upward flow of hydrothermal fluid.
Bulletin. Geothermal Resources Council↗
New explorations along the northern shores of Lake Bonneville
This field trip begins in Salt Lake City and makes a clockwise circuit of Great Salt Lake, with primary objectives to observe stratigraphie and geomorphic records of Lake Bonneville. Stops include Stansbury Island, Puddle Valley, gravel pits at Lakeside and the south end of the Hogup Mountains, several stops in Curlew Valley and Hansel Valley, and a final stop at the north end of Great Salt Lake east of the Promontory Mountains. Stratigraphie observations at gravel-pit and natural exposures will be linked to interpretations of lake-level change, which were caused by climate change. Evidence of paleoseismic and volcanic activity will be discussed at several sites, and will be tied to the lacustrine stratigraphic record. The trip provides an overview of the history of Lake Bonneville and introduces participants to some new localities with excellent examples of Lake Bonneville landforms and stratigraphy.
Brigham Young University Geology Studies↗
Mapping the petroleum system - An investigative technique to explore the hydrocarbon fluid system
Creating a petroleum system map includes a series of logical steps that require specific information to explain the origin in time and space of discovered hydrocarbon occurrences. If used creatively, this map provides a basis on which to develop complementary plays and prospects. The logical steps include the characterization of a petroleum system (that is, to identify, map, and name the hydrocarbon fluid system) and the summary of these results on a folio sheet. A petroleum system map is based on the understanding that there are several levels of certainty from "guessing" to "knowing" that specific oil and gas accumulations emanated from a particular pod of active source rock. Levels of certainty start with the close geographic proximity of two or more accumulations, continues with the close stratigraphic proximity, followed by the similarities in bulk properties, and then detailed geochemical properties. The highest level of certainty includes the positive geochemical correlation of the hydrocarbon fluid in the accumulations to the extract of the active source rock. A petroleum system map is created when the following logic is implemented. Implementation starts when the oil and gas accumulations of a petroleum province are grouped stratigraphically and geographically. Bulk and geochemical properties are used to further refine the groups through the determination of genetically related oil and gas types. To this basic map, surface seeps and well shows are added. Similarly, the active source rock responsible for these hydrocarbon occurrences are mapped to further define the extent of the system. A folio sheet constructed for a hypothetical case study of the Deer-Boar(.) petroleum system illustrates this methodology.
AAPG Memoir↗
Geothermal GIS coverage of the Great Basin, USA: Defining regional controls and favorable exploration terrains
A geographic information system (GIS) of geothermal resources, built last year for the state of Nevada, is being expanded to cover the Great Basin, USA. Data from that GIS is being made available to industry, other researchers, and the public via a web site at the Great Basin Center for Geothermal Energy, Reno, Nevada. That web site features a search engine, supports ArcExplorer?? for on-line map construction, and provides downloadable data layers in several formats. Though data collection continues, preliminary analysis has begun. Contour maps of geothermal temperatures, constructed using geothermometer temperatures calculated from a Great Basin geochemical database compiled by the Geo-Heat Center, reveal distinctive trends and patterns. As expected, magmatic-type and extensional-type geothermal systems have profoundly different associations, with magmatic-type systems following major tectonic boundaries, and extensional-type systems associating with regionally high heat flow, thin crust, active faulting, and high extensional strain rates. As described by earlier researchers, including Rowen and Wetlaufer (1981) and Koenig and McNitt (1983), high-temperature (> 100??C) geothermal systems appear to follow regional northeast trends, most conspicuously including the Humboldt structural zone in Nevada, the "Black Rock-Alvord Desert" trend in Oregon and Nevada, and the "Newcastle-Roosevelt" trend in Utah and Nevada. Weights-of-evidence analyses confirm a preference of high-temperature geothermal systems for young northeast-trending faults, but the distribution of geothermal systems correlates even better with high rates of crustal extension, as measured from global positioning system (GPS) stations in Nevada. A predictive map of geothermal potential based only on areas of high extensional strain rates and high heat flux does an excellent job of regionally predicting the location of most known geothermal systems in Nevada, and may prove useful in identifying blind systems.
Conference Paper↗
New insights into the exploration for Mississippi Valley-type lead-zinc deposits
[No abstract available]
Transactions of the Institution of Mining and Meta↗
Titanic exploration with GIS
To help teachers and students investigate one of the world's most famous historical events using the geographic perspective and GIS tools and methods, the U.S. Geological Survey (USGS) created a set of educational lessons based on the RMS Titanic's April 1912 sailing. With these lessons, student researchers can learn about latitude and longitude, map projections, ocean currents, databases, maps, and images through the analysis of the route, warnings, sinking, rescue, and eventual discovery of the submerged ocean liner in 1985. They can also consider the human and physical aspects of the maiden voyage in the North Atlantic Ocean at a variety of scales, from global to regional to local. Likewise, their investigations can reveal how the sinking of the Titanic affected future shipping routes.
GeoSpatial Solutions↗
Recent exploration activities and coal gas resource potential of the Gulf of Mexico Coastal Plain
No abstract available.
Conference Paper↗
Results of subsurface exploration in the Mid-Island area of western Suffolk County, Long Island, New York
Explore the source record for details and available documents.
New York↗
An exploration of Bureau of Reclamation approaches for managing conflict over diverging science
As a major institutional agent supplying Western water resources, the Bureau of Reclamation (Reclamation) provides important leadership, technical, and financial resources in water management, serving as the West's "water broker" (Bowersox 2000; Pisani 2003). In recent years, growing numbers of constituencies using water and the over-allocation of water resources have contributed to conflict over the resource in the American West (National Research Council 2004). Although the conflicts arise from many sources, one common theme is that Reclamation managers often must make decisions about water use and allocation when scientific studies provide uncertain or competing recommendations. We conducted a preliminary study of Reclamation water managers and water scientists to try to understand the approaches or techniques they use or consider useful for dealing with scientific conflicts over water allocation and how these compare to techniques found in the relevant literature. We report the results of (1) an electronic survey of Reclamation senior managers and (2) a panel discussion amongst Reclamation senior managers as to the current institutional capabilities for managing diverging scientific findings in water dispute resolution processes. We conclude with a discussion of the strengths and weaknesses of the different tools and techniques managers reported in the survey and in the panel discussion.
Technical Memorandum↗