Geology Reports⌕ Search

SEARCH · Geology Reports

Results for “General Mineral Resource Map”

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 37 records · Page 2Linked to original sources
USGS2006

Preliminary integrated geologic map databases for the United States: Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, Rhode Island and Vermont

The rapid growth in the use of Geographic Information Systems (GIS) has highlighted the need for regional and national scale digital geologic maps that have standardized information about geologic age and lithology. Such maps can be conveniently used to generate derivative maps for manifold special purposes such as mineral-resource assessment, metallogenic studies, tectonic studies, and environmental research. Although two digital geologic maps (Schruben and others, 1994; Reed and Bush, 2004) of the United States currently exist, their scales (1:2,500,000 and 1:5,000,000) are too general for many regional applications. Most states have digital geologic maps at scales of about 1:500,000, but the databases are not comparably structured and, thus, it is difficult to use the digital database for more than one state at a time. This report describes the result for a seven state region of an effort by the U.S. Geological Survey to produce a series of integrated and standardized state geologic map databases that cover the entire United States. In 1997, the United States Geological Survey's Mineral Resources Program initiated the National Surveys and Analysis (NSA) Project to develop national digital databases. One primary activity of this project was to compile a national digital geologic map database, utilizing state geologic maps, to support studies in the range of 1:250,000- to 1:1,000,000-scale. To accomplish this, state databases were prepared using a common standard for the database structure, fields, attribution, and data dictionaries. For Alaska and Hawaii new state maps are being prepared and the preliminary work for Alaska is being released as a series of 1:250,000 scale quadrangle reports. This document provides background information and documentation for the integrated geologic map databases of this report. This report is one of a series of such reports releasing preliminary standardized geologic map databases for the United States. The data products of the project consist of two main parts, the spatial databases and a set of supplemental tables relating to geologic map units. The datasets serve as a data resource to generate a variety of stratigraphic, age, and lithologic maps. This documentation is divided into four main sections: (1) description of the set of data files provided in this report, (2) specifications of the spatial databases, (3) specifications of the supplemental tables, and (4) an appendix containing the data dictionaries used to populate some fields of the spatial database and supplemental tables.

Connecticut, Maine, Massachusetts, New Hampshire, ↗
USGS1975

The Alaskan mineral resource assessment program; background information to accompany folio of geologic and mineral resource maps of the Nabesna Quadrangle, Alaska

The Nabesna quadrangle in south-central Alaska is the first of the l:250,000-scale Alaskan quadrangles to be investigated by an interdisciplinary research team in order to furnish a mineral resource assessment of the State. The assessment of the 17,600-km 2 16,800-mi21 quadrangle is based on field and laboratory investigations of the geology, geochemistry, geophysics, and satellite imagery. The results of the investigations are published as a folio of maps, diagrams, and accompanying discussions. This report provides background information on the investigations and integrates the published components of the resource assessment. A comprehensive bibliography cites both specific and general references to the geology and mineral deposits of the Nabesna quadrangle.

Circular↗
USGS1974

Selected U.S. Bureau of Mines reports on Alaska indexed by quadrangle

Most U.S. Bureau of Mines reports on the geology and mineral resources of Alaska that were published or placed in open files through April 30, 1974, are listed by the quadrangles (scale 1:250,000) into which Alaska has been divided for topographic mapping (p. 2). References to reports that deal with Alaska as a whole and cannot be readily assigned to individual quadrangles or deal with many scattered parts of the state are listed under ALASKA - GENERAL, which appears before the alphabetically arranged quadrangle listings. References to the Minerals Yearbook, published annually, are not included as this periodical contains mainly statistical data. Also omitted are reports on mining, milling, and metallurgical practices; compilations of coal, oil, and gas analyses unless data on geological occurrences are also given; and reports on permissible explosives, health, and safety. This index is the second in a planned series of specialized lists, arranged by quadrangle, that will facilitate library research on the geology and mineral resources of Alaska. The first in the series is "Geological Survey open-file reports on Alaska indexed by quadrangle," by Edward H. Cobb, which was released as open-file report 74-7 on May 16, 1974.

Alaska↗
USGS1906

Geology of the Bighorn Mountains

This report is the result of studies made in the field during the seasons of 1901, 1902, 1903, 1904, and 1905. It relates to an area of about 9,000 square miles, situated mainly in the north-central portion of Wyoming and extending northward into Montana. Its location and general surroundings are shown on PL II. It covers the greater portion of the Bighorn uplift, together with an adjoining area of the Great Plains on the east. It also includes a small part of the Bighorn Basin and the eastern end of the Bridger Range. The report describes the various rocks, their structure, history, and mineral resources, including underground water, coal, gypsum, and various other products. It also contains information as to surface waters available for irrigation. Throughout the work assistance has been rendered by Mr. C. A. Fisher, who mapped portions of the area, measured numerous sections, collected fossils, and examined most of the crystalline rocks; and the author is indebted to Mr. Albert Johannsen for some of the petrographic descriptions. Previous observers have given but little information regarding the geology of the Bighorn Mountains, though Dr. F. V. Hayden ascertained the general relations of the uplift in his exploration of the Northwest, and Mr. George H. Eldridge, who crossed the range near Bald Mountain and southwest of Buffalo during the summer of 1893, described 0 some of the broader features of the geologic succession and structure in a remarkably comprehensive manner, considering how small an area he had the opportunity to examine. The Bighorn region is very thinly settled, there being no permanent habitations among the mountains, and it is but little visited by others than hunters, prospectors, and herders. There have recently been established two summer resorts in the mountains, and each year a larger number of persons visit the region. Unfortunately the mineral prospects have proved disappointing to the prospectors, and there appears to be but little promise that the area will become important on account of its mineral resources. In the Bridger uplift promising prospects of gold and copper have recently been discovered, which may prove of value. There are extensive, forests in the mountains, which are now included in a Government forest reserve, but their timber is not of great value. Much of the area below timber line contains an abundance of luxuriant grasses and other plants, which afford excellent pasturage for stock, and large herds of sheep and cattle are ranged in the region during the short summer season. Game is moderately abundant, and most of the streams contain large numbers of trout. The region is one of great interest geologically on account of its variety of sedimentary rocks, interesting structure, and remarkably instructive glacial features. The central area, with its high peaks, presents alpine scenery of notable character. Doubtless in the future the region will be extensively visited by tourists, hunters, and geologists.

Montana, Wyoming↗
USGS1987

BIA interpretation techniques for vegetation mapping using thematic mapper false color composites (interim report for San Carlos Reservation)

The Bureau of Indian Affairs (BIA) is responsible for the natural resource management of approximately 52 million acres of Trust lands in the contiguous United States. The lands are distributed in a "patchwork" fashion throughout the country. Management responsibilities on these areas include: minerals, range, timber, fish and wildlife, agricultural, cultural, and archaeological resources. In an age of decreasing natural resources and increasing natural resource values, effective multiple resource management is critical. BIA has adopted a "systems approach" to natural resource management which utilizes Geographic Information System (GIS) technology. The GIS encompasses a continuum of spatial and relational data elements, and included functional capabilities such as: data collection, data entry, data base development, data analysis, data base management, display, and report generalization. In support of database development activities, BIA and BLM/TGS conducted a cooperative effort to investigate the potential of 1:100,000 scale Thematic Mapper (TM) False Color Composites (FCCs) for providing vegetation information suitable for input to the GIS and to later be incorporated as a generalized Bureau wide land cover map. Land cover information is critical as the majority of reservations currently have no land cover information in either map or digital form. This poster outlines an approach which includes the manual interpretation of land cover using TM FCCs, the digitizing of interpreted polygons, and the editing of digital data, used upon ground truthing exercises. An efficient and cost-effective methodology for generating large area land cover information is illustrated for the Mineral Strip area on the San Carlos Indian Reservation in Arizona. Techniques which capitalize on the knowledge of the local natural resources professionals, while minimizing machine processing requirements, are suggested.

Arizona↗
USGS1979

Investigations needed to stimulate the development of Jordan's mineral resources

The level of living that any society can attain is a direct function of the use it makes of all kinds of raw materials (soil, water, metals, nonmetals, etc.), all kinds of energy (both animate and inanimate), and all kinds of human ingenuity; and is an inverse function of the size of the population that must share the collective product. The relation between raw materials, energy and ingenuity is such that use of a large amount of one may offset the need for large amounts of others. The most vital raw materials are water, soil, and construction materials, for these are needed in large quantities and are hard to import. Metals, chemicals, and inanimate energy are necessary for industrialization. The more of these minerals a nation possess, the better, but not nation can hope to be self-sufficient in all of the m and therefore must trade for some essential materials. Jordan’s natural resources have been little explored. The grantitc-metamorphic terrane in the southeastern part of the Kingdom could contain deposits of tungsten, rare earths, feldspar, mica, fluorite etc. and the sedimentary terrane over much of the rest of the county is favorable for the occurrence of oil. Even if none of these minerals is found, however, Jordan’s other mineral resource, if fully explored and developed in the light of modern technology, will support a far higher level of living than her people now enjoy. Very likely she can increase her rainfall by about 10 percent by cloud seeding, and she undeveloped supplies in both surface and ground water that are sufficient to nearly double her usable water supply. Even if she does not have oil or have it in large quantities, she can buy it cheaply from neighboring counties, and in addition has undeveloped sources of hydroelectric power, large reserves of bituminous limestone, large reserves of nuclear power as uranium in phosphate rock, and can use solar and wind power for special purposes. Her large supplies of construction, fertilizer, and other chemical raw materials will not only satisfy her own needs, but will yield both raw materials and some manufactured products for export. And she has valuable resource of touristic interest in the form of incomparable scenery, antiquities, and holy places, which, if properly advertised, could well become her largest single source of foreign currency. Revenues obtained from this source and from the export of agricultural products, nonmetallic minerals, and mineral products should support foreign oil purchase of oil, machinery, and other products not mined or produced internally. Full development of Jordan’s economic potential will take years to achieve and involves many complex activities. One of the most essential is one that can be pressed in the early years, namely the gathering of facts and basic data concerning the character, extent, and distribution of her resources, and the uses that can be made of them. Without each fundamental data or the understanding of their meaning or the ways to use and apply them, costly developmental projects and similar efforts to raise the level of living are likely to have limited success at best. Basic data and mineral resources are best gathered and published by permanent government agencies, for private organizations and individual cannot afford to take the risks involved in gathering data that may not have an immediate economic return; and even if private parties do collect such data they are not likely to make them general available. Of the activities needed in the field of mineral resources, some are already underway as the established function of government agencies. No bureau however, seems to have responsibility for making geologic maps and for gathering data on such things as steam flow, composition and properties of minerals and rocks, or for investigating the uses to which Jordan’s minerals might be put. To satisfy these needs, a Geological Survey and a Bureau of Mineral Industries should be formed and placed in operation as quickly as possible. The task of collecting and interpreting basic data or mineral resources must be done largely by Jordanians, for only in this way will Jordan acquire the technical competence needed to use the information. Few Jordanians have enough training or experience to work independently in these fields now, however, so help from outside technicians would be necessary over an initial training period of several years. But the number of outside technicians should never exceed the number of Jordanian technicians, and for this reason, neither organization could have a staff of more than a few people during the early years of operation.

Open-File Report↗
USGS2013

Tectonic map of the Circum-Pacific region, Pacific basin sheet

Circum-Pacific Map Project : The Circum-Pacific Map Project was a cooperative international effort designed to show the relationship of known energy and mineral resources to the major geologic features of the Pacific basin and surrounding continental areas. Available geologic, mineral, and energy-resource data are being complemented by new, project-developed data sets such as magnetic lineations, seafloor mineral deposits, and seafloor sediment. Earth scientists representing some 180 organizations from more than 40 Pacific-region countries are involved in this work. Six overlapping equal-area regional maps at a scale of 1:10,000,000 form the cartographic base for the project: the four Circum-Pacific Quadrants (Northwest, Southwest, Southeast, and Northeast), and the Antarctic and Arctic Sheets. There is also a Pacific Basin Sheet at a scale of 1:17,000,000. The Base Map Series and the Geographic Series (published from 1977 to 1990), the Plate-Tectonic Series (published in 1981 and 1982), the Geodynamic Series (published in 1984 and 1985), and the Geologic Series (published from 1984 to 1989) all include six map sheets. Other thematic map series in preparation include Mineral-Resources, Energy-Resources and Tectonic Maps. Altogether, more than 50 map sheets are planned. The maps were prepared cooperatively by the Circum-Pacific Council for Energy and Mineral Resources and the U.S. Geological Survey and are available from the Branch of Distribution, U. S. Geological Survey, Box 25286, Federal Center, Denver, Colorado 80225, U.S.A. The Circum-Pacific Map Project is organized under six panels of geoscientists representing national earth-science organizations, universities, and natural-resource companies. The six panels correspond to the basic map areas. Current panel chairmen are Tomoyuki Moritani (Northwest Quadrant), R. Wally Johnson (Southwest Quadrant), Ian W.D. Dalziel (Antarctic Region), vacant. (Southeast Quadrant), Kenneth J. Drummond (Northeast Quadrant), and George W. Moore (Arctic Region). Project coordination and final cartography was being carried out through the cooperation of the Office of the Chief Geologist of the U.S. Geological Survey, under the direction of General Chairman, George Gryc of Menlo Park, California. Project headquarters were located at 345 Middlefield Road, MS 952, Menlo Park, California 94025, U.S.A. The framework for the Circum-Pacific Map Project was developed in 1973 by a specially convened group of 12 North American geoscientists meeting in California. The project was officially launched at the First Circum-Pacific Conference on Energy and Mineral Resources, which met in Honolulu, Hawaii, in August 1974. Sponsors of the conference were the AAPG, Pacific Science Association (PSA), and the Coordinating Committee for Offshore Prospecting for Mineral Resources in Offshore Asian Areas (CCOP). The Circum-Pacific Map Project operates as an activity of the Circum-Pacific Council for Energy and Mineral Resources, a nonprofit organization that promotes cooperation among Circum-Pacific countries in the study of energy and mineral resources of the Pacific basin. Founded by Michel T. Halbouty in 1972, the Council also sponsors conferences, topical symposia, workshops and the Earth Science Series books. Tectonic Map Series : The tectonic maps distinguish areas of oceanic and continental crust. Symbols in red mark active plate boundaries, and colored patterns show tectonic units (volcanic or magmatic arcs, arc-trench gaps, and interarc basins) associated with active plate margins. Well-documented inactive plate boundaries are shown by symbols in black. The tectonic development of oceanic crust is shown by episodes of seafloor spreading. These correlate with the rift and drift sequences at passive continental margins and episodes of tectonic activity at active plate margins. The recognized episodes of seafloor spreading seem to reflect major changes in plate kinematics. Oceanic plateaus and other prominences of greater than normal oceanic crustal thickness such as hotspot traces are also shown. Colored areas on the continents show the ages of deformation and metamorphism of basement rocks and the emplacement of igneous rocks. Transitional tectonic (molassic) and reactivation basins are shown by a colored boundary, and if they are deformed, a colored horizontal line pattern indicates the age of deformation. Colored bands along basin boundaries indicate age of inception, and isopachs indicate thickness of platform strata on continental crust and cover on oceanic crust. Colored patterns at separated continental margins show the age of inception of rift and drift (breakup) sequences. Symbols mark folds and faults, and special symbols show volcanoes and other structural features. Affiliations are as of compilation of the data. This map was created in quadrants and then compiled together. They are the Northwest land, Northwest Marine (different compilers), Northeast, Southwest and Southeast, and parts in plate-boundary sections.

Circum-Pacific Map↗
USGS1883

Geology of Wisconsin: Survey of 1873-1879, Volume I

The leading purpose df this volume was determined by the following enactment, being section 1, chapter 121, of the Laws of 1876. " The people of the State of Wisconsin, represented in Senate and Assembly, do enact as follows: Section 1. That in the preparation of his final report, the chief geologist be, and he is hereby authorized to collate the general geology and the leading facts and principles relating to the material resources of the State, together with practical suggestions as to the methods of detecting and utilizing the same, so as to constitute the material for a volume suited to the wants of explorers, miners, land owners, and manufacturers, who use crude native products, and to the needs of the schools of the State, and the masses of intelligent people who are not familiar with the principles of geology; said volume to be written in clear, plain language, with explanations of technical terms, and to be properly illustrated with maps and diagrams, and to be so arranged as to constitute a key to the more perfect understanding of the whole report." To subserve the purposes thus legally defined, the volume will be found to consist of three distinct portions; Part I, embracing the General Geology of the State, with explanatory matter; Part II, consisting of lists of the minerals, rocks and life-products of the State, with descriptions and auxiliary discussions; and Part III, embracing industrial descriptions and practical suggestions with reference to the leading natural resources of the State.

Wisconsin↗
USGS1992

Map, tables, and summary of fossil and isotopic age data, Mount Hayes Quadrangle, eastern Alaska range, Alaska

This report describes, summarizes, and interprets all known bedrock fossil and isotopic age studies for the Mount Hayes quadrangle, eastern Alaska Range, Alaska. The accompanying map shows the location of all known bedrock fossil and isotopic sample localities in the quadrangle on a generalized geologic base map. These fossil and isotopic age data are obtained from new studies, unpublished data of the U.S. Geological Survey, contributed unpublished data, and published data. This report is one result of a five-year mineral resource assessment of the quadrangle that was done during the summers of 1978 through 1982, with additional topical studiesin 1985 and 1986. This report is one part of a folio on the geological, geochemical, geophysical, and mineral-resource assessment studies of the quadrangle prepared as part of the Alaskan Mineral Resource Assessment Program (AMRAP) of the U.S. Geological Survey.

Alaska↗
USGS1991

Regional study of mineral resources in Nevada: Insights from three-dimensional analysis of gravity and magnetic anomalies

A three-dimensional interpretation of the basins of Nevada was developed based on statewide data bases of digital-gravity, magnetic, geologic, well, and topographic information. An iterative technique was applied to isostatic residual gravity anomalies in Nevada in order to define the location and shape of pre-Tertiary basement and to produce a gravity map that reflects variations of density within the pre-Tertiary basement. The dominant feature of the basement gravity of Nevada is an enormous area of low gravity that spans the entire state between latitudes 37°N and 40.5°N. This regional low strongly correlates with the distribution of middle and late Tertiary volcanic rocks and may reflect silicic intrusions within the mid-crust and upper crust that are the counterparts of volcanic rocks at the surface. Although 80% of Nevada is covered by Cenozoic deposits, these deposits are thicker than 1 km over only about 20% of the state. The remaining 60% of Nevada may have pre-Tertiary basement rocks within reach of current mineral-exploration techniques. Aeromagnetic profiles from the National Uranium Resource Evaluation (NURE) were analyzed in order to produce a map showing the location of shallow magnetic sources in Nevada. This analysis shows that 46% of the state has magnetic sources, generally Mesozoic and Cenozoic igneous rocks, within 1 km of the surface. A linear magnetic anomaly in north-central Nevada has been interpreted by others as a rift zone active during middle Miocene time. The rift also is evident in NURE magnetic profiles, but our interpretation suggests that the magnetic expression of the rift continues south-southeast with similar strike to at least 38°N and perhaps to the amagmatic zone (lat. 37°N). The survival since the middle Miocene of this narrow crustal feature, essentially linear over a distance of 500 km, is difficult to interpret in light of later Basin and Range deformation. Our analysis of gravity anomalies shows that many deep Cenozoic basins are located near the rift, yet only two basins cut across it, and at least five others change strike near the rift, as if to avoid it. The rift may have remained linear because it is associated with crustal structures that acted to resist subsequent deformation.

Nevada↗
USGS1988

Heavy-Mineral Placer Potential Map of the U.S. Continental Shelf, Western and Northern Gulf of Mexico

The establishment of the Exclusive Economic Zone (EEZ) in 1983 by Presidential Proclamation opened for natural resource exploration a vast offshore frontier area contiguous to the United States and its territories. The EEZ extends from the seaward limit of state waters (3 nautical mi from shore) to 200 nautical mi offshore, and it includes the continental shelves. Within the context of the EEZ natural resource assessment effort, the purpose of this study is to delineate, on a regional basis, the potential for heavy-mineral placers on the U.S. Continental Shelf in the western and northern Gulf of Mexico from the United States-Mexico border to the Alabama-Florida state line. This map is intended to serve as a general guide for placer exploration. It shows favorable sea-floor areas for placer occurrence in water depths ranging from 0 to 100 fathoms (600 ft). The map can be used as a guide for focusing costly exploratory efforts, such as coring operations and geophysical surveys. The potential economic value of heavy-mineral placer concentrations on the U.S. Continental Shelf is a function of both geologic and economic variables. Geologic variables include the composition and concentration of the heavy-mineral assemblages and their environment of deposition. Economic variables include the current world market price of extracted metals, as well as the cost of mining, processing, and marketing the metals. These economic factors, in turn, are tempered by the nation1s socio-political climate, which determines its need for specific mineral resources at any given time.

Miscellaneous Field Studies Map↗
USGS2012

Lineament analysis of mineral areas of interest in Afghanistan

During a preliminary mineral resource assessment of Afghanistan (Peters and others, 2007), 24 mineralized areas of interest (AOIs) were highlighted as the focus for future economic development throughout various parts of the country. In addition to located mineral resources of value, development of a viable mining industry in Afghanistan will require the location of suitable groundwater resources for drinking, processing of mineral ores for use or for export, and for agriculture and food production in areas surrounding and supporting future mining enterprises. This report and accompanying GIS datasets describe the results of both automated and manual mapping of lineaments throughout the 24 mineral occurrence AOIs described in detail by Peters and others (2007; 2011). For this study, we define lineaments as "mappable linear or curvilinear features of a surface whose parts align in a straight or slightly curving relationship that may be the expression of a fault or other linear zones of weakness" as derived from remote sensing sources such as optical imagery, radar imagery or digital elevation models (DEMs) (Sabins, 2007). Water wells in bedrock aquifers are generally more productive where boreholes intersect fractures or fracture zones. Lineament identification and analysis have long been used as a reconnaissance tool to identify such favorable conditions for groundwater resources in carbonate bedrock environments (Lattman and Parizek, 1964; Siddiqui and Parizek, 1971). More recently, lineament analysis has been used to identify areas of greater well yields in other bedrock settings, such as crystalline bedrock (Mabee and other, 1994; Moore and others, 2002). Lineaments provide an indication of bedrock areas that warrant further investigation for optimal water well placement. They may also indicate areas of preferential flow and storage of groundwater, and, thus, areas with a greater density of lineaments may indicate greater secondary porosity. Lineaments may indicate structurally trending mineralized areas (for example, Mars and Rowan, 2007), or locations of near-surface water resources, especially when surface vegetation growth coincides with lineaments. The purpose of this report and accompanying GIS data is to provide lineament maps that give one indication of areas that warrant further investigation for optimal bedrock water-well placement within 24 target areas for mineral resources (Peters and others, 2011). These data may also support the identification of faults related to modern seismic hazards (for example, Wheeler and others, 2005; Ruleman and others, 2007), as well as support studies attempting to understand the relationship between tectonic and structural controls on hydrothermal fluid flow, subsequent mineralization, and water-quality issues near mined and unmined mineral deposits (for example, Eppinger and others, 2007).

Open-File Report↗
USGS1905

Geology of the central Copper River region, Alaska

It is an interesting evidence of the prompt responsiveness of our governmental organization to popular needs that the year 1898, which saw the first rush of argonauts to Alaska as a result of the discovery of the Klondike in 1986, saw also several well-equipped Federal parties at work in the Territory, mapping its great waterways and mountain ranges, investigating the feasible means of transportation within it, laying out routes for future lines of communication, and studying the mineral resources and the plant and animal life. It is true that before that year, in which the general attention of the world was fixed upon our heretofore lightly regarded northern province, fur traders, adventurous travelers, and hardy prospectors had made little-heralded journeys through the interior, and that one or another of the governmental departments had had representatives on special errands within its borders, but the amount of private and public energy expended there in 1898 probably exceeded that of any ten previous years.

Alaska↗
USGS2006

Preliminary integrated geologic map databases for the United States: Digital data for the generalized bedrock geologic map, Yukon Flats region, east-central Alaska

The growth in the use of Geographic Information Systems (GIS) has highlighted the need for digital geologic maps that have been attributed with information about age and lithology. Such maps can be conveniently used to generate derivative maps for manifold special purposes such as mineral-resource assessment, metallogenic studies, tectonic studies, and environmental research. This report is part of a series of integrated geologic map databases that cover the entire United States. Three national-scale geologic maps that portray most or all of the United States already exist; for the conterminous U.S., King and Beikman (1974a,b) compiled a map at a scale of 1:2,500,000, Beikman (1980) compiled a map for Alaska at 1:2,500,000 scale, and for the entire U.S., Reed and others (2005a,b) compiled a map at a scale of 1:5,000,000. A digital version of the King and Beikman map was published by Schruben and others (1994). Reed and Bush (2004) produced a digital version of the Reed and others (2005a) map for the conterminous U.S. The present series of maps is intended to provide the next step in increased detail. State geologic maps that range in scale from 1:100,000 to 1:1,000,000 are available for most of the country, and digital versions of these state maps are the basis of this product. The digital geologic maps presented here are in a standardized format as ARC/INFO export files and as ArcView shape files. Data tables that relate the map units to detailed lithologic and age information accompany these GIS files. The map is delivered as a set 1:250,000-scale quadrangle files. To the best of our ability, these quadrangle files are edge-matched with respect to geology. When the maps are merged, the combined attribute tables can be used directly with the merged maps to make derivative maps.

Alaska↗
USGS2004

Book review: The future of Antarctica

A conference on Antarctica: an Exploitable Resource too Valuable to Develop? took place at the Sir Robert Menzies Centre for Australian studies at the University of London in either late 1989 or early 1990. The papers were compiled into this small book (only 104 pages of text exclusive of useful appendices containing maps, texts of the Antarctic treaty and the Convention on the regulation of Antarctic Mineral Resource Activity [CRAMRA]) which addresses the hottest issues confronting the Antarctic Treaty Consultative Parties in the early 1990’s. Some of the discussion is being overtaken by events, but fortunately, the general quality and broadness of the coverage will make the book useful to diplomats, historians, international lawyers, scientists and other environmentalists for some time to come.

Antarctic Science↗
USGS1996

Digital representation of the Washington state geologic map: a contribution to the Interior Columbia River Basin Ecosystem Management Project

This report describes the digital representation of the Washington state geologic map (Hunting and others, 1961). This report contains an explantion of why the data were prepared, a description of the digital data, and information on obtaining the digital files. This report is one in a series of digital maps, data files, and reports generated by the U.S. Geological Survey to provide geologic process and mineral resource information to the Interior Columbia Basin Ecosystem Management Project (ICBEMP). The various digital maps and data files are being used in a geographic information system (GIS)-based ecosystem assessment including an analysis of diverse questions relating to past, present, and future conditions within the general area of the Columbia River Basin east of the Cascade Mountains.

Open-File Report↗
USGS1982

The Alaska Mineral Resource Assessment Program: Guide to information about the geology and mineral resources of the Ketchikan and Prince Rupert quadrangles, southeastern Alaska

The Ketchikan and Prince Rupert 1-degree by 2-degree quadrangles, which encompass about 16,000 km2 at the south tip of southeastern Alaska, have been investigated by integrated field and laboratory studies in the disciplines of geology, geochemistry, geophysics, and Landsat data interpretation to determine their mineral-resource potential. Mineral deposits in the study area have been mined or prospected intermittently since about 1900, and production of small tonnages of ores containing gold, silver, copper, lead, zinc, and tungsten has been recorded. Extensive exploration and development currently (1981) is underway at a molybdenum prospect about 65 km east of Ketchikan. Our mineral-resource assessment indicates that the area contains potentially significant amounts of those metallic commodities, as well as of molybdenum, iron, antimony, and barite. The results of these studies have been published in a folio of maps accompanied by descriptive texts, diagrams, tables, and pertinent references. The present report serves as a guide to these investigations, provides relevant background information, and integrates the component maps and reports. It also describes revisions to the geology based on studies completed since the folio was published and includes a list of specific and general references on the geology and mineral deposits of the study area.

Alaska↗
USGS1987

Oblique map of the northern Sierra Nevada, California, showing location of gold-bearing areas

More than a third of the gold produced by the United States was mined in California. The bulk of this gold was recovered from the western slope of the northern half of the Sierra Nevada between the Merced River in the south and the Feather River to the north, a distance of about 170 mi. Gold was first discovered, in this region, on the American River at Coloma in 1848, triggering the famed California gold rush. Mining was continuously active, somewhere in the area, from the discovery of gold until World War II when mining was legally prohibited. Dramatic increases in gold prices in the past decade coupled with recent advances in extractive techniques have revitalized prospecting, and major deposits are currently being explored and developed. Gold has been found in a variety of geologic environments in the region. In addition to production from the complex vein systems of the historically famous Mother Lode and associated East Gold Belt and West Gold Belt, large amounts of gold have also been recovered from the Grass Valley-Nevada City and other isolated lode districts and from Tertiary river channels and Quaternary alluvium. This oblique map illustrates the relation of the different gold-bearing environments to each other and to the general terrain of the northern Sierra Nevada. The map was derived from the 1970 U.S. Geological Survey 1:500,000-scale topographic map of California and the 1976 U.S. Geological Survey 1:500,000-scale topographic map of Nevada, using an isometrograph, a mechanical instrument that produces an oblique framework by tracing individual contours. Form lines sketched over this framework graphically portray the physiographic configuration of the region. Relief on the oblique map has a 3:1 vertical exaggeration and appears as if viewed from a 30° angle above the horizon. Locations of lode gold prospects and mines shown on the map were obtained from the U.S. Geological Survey's Mineral Resource Data System (MRDS), a computerized mineral-resource information file, and plotted in their respective locations (D.F. Huber, written commun., 1986). Some locations from two northern counties, missing from the MRDS retrival, were added. The twenty lode mines believed to be the most productive are cited in table 1. A total of nearly 4,000 sites, including both prospects and mines, were initially plotted, but about a third of those were obscured by topography on the oblique map. Locations of Tertiary river channels and gold-dredging fields were taken from published general references modified by examining specific sources and by cursory field examination. Seven of the major dredge fields are identified in table 2.

California↗