Results for “Minerals” — Page 40

USGS1997

Natural and mining-related sources of dissolved minerals during low flow in the Upper Animas River Basin, southwestern Colorado

As part of the Clean Water Act of 1972 (Public Law 92-500), all States are required to establish water-quality standards for every river basin in the State. During 1994, the Colorado Department of Public Health and Environment proposed to the Colorado Water Quality Control Commission (CWQCC) an aquatic-life standard of 225 µg/L (micrograms per liter) for the dissolved-zinc concentration in the Animas River downstream from Silverton (fig.1). The CWQCC delayed implementation of this water-quality standard until further information was collected and a plan for the cleanup of abandoned mines was developed. Dissolved-zinc concentrations in this section of the river ranged from about 270 µg/L during high flow, when rainfall and snowmelt runoff dilute the dissolved minerals in the river (U.S. Geological Survey, 1996, p. 431), to 960 µg/L (Colorado Department of Public Health and Environment, written commun., 1996) during low flow (such as late summer and middle winter when natural springs and drainage from mines are the main sources for the streams). Mining sites in the basin were developed between about 1872 and the 1940's, with only a few mines operated until the early 1990's. For local governments, mining sites represent part of the Nation's heritage, tourists are attracted to the historic mining sites, and governments are obligated to protect the historic mining sites according to the National Historic Preservation Act (Public Law 89-665). In the context of this fact sheet, the term "natural sources of dissolved minerals" refers to springs and streams where no effect from mining were determined. "Mining-related sources of dissolved minerals" are assumed to be: (1 ) Water draining from mines , and (2) water seeping from mine-waste dump pile where the waste piles were saturated by water draining from mines. Although rainfall and snowmelt runoff from mine-waste piles might affect water quality in streams, work described in this fact sheet was done during low-flow conditions when springs and drainage from mine were the main sources of dissolved minerals affecting the streams. Data are being collected by the U.S. Geological Survey (USGS) to determine the magnitude and sources of dissolved minerals during rainfall- and snowmelt-runoff periods. This fact sheet presents results of studies done by the USGS in collaboration with the Animas River Stakeholders Group and was prepared in cooperation with the Southwestern Colorado Water Conservation District. The studies were done at selected sites in the Upper Animas River Basin to determine natural and mining-related sources of dissolved minerals and are continuing in the basin with the Animas River Stakeholders Group and as part of the Department of the Interior Abandoned Mine Lands Initiative. The results of these studies will provide useful information for determining water-quality standards in the basin.

Colorado↗

USGS2017

Geospatial analysis identifies critical mineral-resource potential in Alaska

Alaska consists of more than 663,000 square miles (1,717,000 square kilometers) of land—more than a sixth of the total area of the United States—and large tracts of it have not been system atically studied or sampled for mineral- resource potential. Many regions of the State are known to have significant mineral-resource potential, and there are currently six operating mines in the State along with numerous active mineral exploration projects. The U.S. Geologi cal Survey and the Alaska Division of Geological & Geophysical Surveys have developed a new geospatial tool that integrates and analyzes publicly available databases of geologic information and estimates the mineral-resource potential for criti cal minerals, which was recently used to evaluate Alaska. The results of the analyses highlight areas that have known mineral deposits and also reveal areas that were not previously considered to be prospective for these deposit types. These results will inform land manage ment decisions by Federal, State, and private landholders, and will also help guide future exploration activities and scientific investigations in Alaska.

Alaska↗

USGS1992

Map showing mineral resource assessment for vein and replacement deposits of gold, silver, copper, lead, zinc, manganese, and tungsten in the Butte 1° x 2° quadrangle, Montana

The purpose of this report is to assess the potential for undiscovered vein and replacement deposits of gold, silver, copper, lead, zinc, manganese, and tungsten in the Butte 1° x 2° quadrangle. This quadrangle, in west-central Montana, is one of the most mineralized and productive regions in the United States. Its mining districts, including the world famous Butte or Summit Valley district, have produced a variety of metallic and nonmetallic mineral commodities valued at more than $6.4 billion. Because of its importance as a mineral producing region, the Butte quadrangle was selected for study by the U.S. Geological Survey under the Conterminous United States Mineral Assessment Program (CUSMAP). Under this program, new data on geology, geochemistry, geophysics, geochronology, mineral resources, and remote sensing were collected and synthesized. The field and laboratory studies were also supported by funding from the Geologic Framework and Synthesis Program and the Wilderness Program. The methods used in resource assessment include a compilation of all data into data sets, the development of a descriptive model for vein and replacement deposits in the quadrangle, and the analysis of data using techniques provided by the Geographic Information System (GIS). This map is one of a number of reports and maps on the Butte 1 °X2° quadrangle. Other publications resulting from this study include U.S. Geological Survey Miscellaneous Investigations Series Maps 1-2050-A (Rowan and Segal, in press) and I-2050-B (Purdy and Rowan, in press); Miscellaneous Field Studies Map MF-1925 (Wallace, 1987); and Open-File Reports 86-292 (Wallace and others, 1986) and 86--0632 (Elliott and others, 1986). Reports on mineral resource assessment for several other types of deposits in the Butte quadrangle are in preparation.

Montana↗

USGS1993

Maps showing mineral resource assessment for porphyry and stockwork deposits of copper, molybdenum, and tungsten and for stockwork and disseminated deposits of gold and silver in the Butte 1° x 2° quadrangle, Montana

This report documents the assessment for potential occurrences of undiscovered porphyry and stockwork deposits of copper, molybdenum, and tungsten (porphyry Cu-Mo-W) and stockwork and disseminated deposits of gold and silver (disseminated Au-Ag) in the Butte 1 °X2° quadrangle. The Butte quadrangle, in west-central Montana, is one of the best known mineral producing regions in the U.S. Mining districts in the quadrangle, including the world famous Butte or Summit Valley district, have produced a variety of metallic and nonmetallic mineral commodities valued at more than $6.4 billion (at the time of production). Because of its importance as a mineral producing region, the Butte quadrangle was selected for study by the U.S. Geological Survey under the Conterminous United States Mineral Assessment Program (CUSMAP). Under this program, new data on geology, geochemistry, geophysics, geochronology, mineral resources, and remote sensing were collected and synthesized. The field and laboratory studies were supported, in part, by funding from the Geologic Framework and Synthesis Program and the Wilderness Program. The methods used in this resource assessment for porphyry Cu-Mo-W and disseminated Au-Ag deposits in the quadrangle include a compilation of all data, the development of descriptive occurrence models, and the analysis of data using techniques provided by a Geographic Information System (GIS). This map is one of several maps on the Butte 1 °X2° quadrangle. Other deposit types have been assessed for the Butte quadrangle, and maps (U.S. Geological Survey (USGS) Miscellaneous Investigation Series Maps) for each of the following have been prepared: Vein and replacement deposits of gold, silver, copper, lead, zinc, manganese, and tungsten (Elliott, Wallace, and others, 1992a) and skarn deposits of gold, silver, copper, tungsten, and iron (Elliott and others, 1992b ). Other publications resulting from this study include linear features map (Rowan and others, 1991 ); limonite and hydrothermal alteration map (Rowan and Segal, 1989); mineral occurrence maps (Elliott and others, 1986; Elliott, Loen, and others, 1992); and geologic maps (Wallace, 1987; Wallace and others, 1987).

Montana↗

USGS1985

Maps showing distribution of copper in heavy-mineral concentrates, Richfield 1° x 2° quadrangle, Utah

These maps are part of a folio of maps of the Richfield 1° x 2 ° quadrangle, Utah, prepared under the Conterminuous United States Mineral Assessment Program. Other publications in this folio are listed in the selected references. Located in west-central Utah, the Richfield quadrangle covers the eastern part of the Plioche-Marysvale igneous and mineral belt, which extends from the vicinity of Plioche in southeastern Nevada east-northeastward for 250 km (155 mi) into central Utah. The western two-thirds of the Richfield quadrangle is in the Basin and Range province and the eastern third is in the High Plateaus of Utah, a subprovince of the Colorado Plateau. Bedrock in the northern part of the Richfield quadrangle consists predominantly of latest Precambrian and Paleozoic sedimentary strata that were thrust eastward during the Sevier orogeny in Cretaceous time onto an autochthon of Mesozoic sedimentary rocks in the eastern part of the quadrangle. The southern part of the quadrangle is largely underlain by Oligocene and younger volcanic rocks and related intrusions. Extensional tectonism in late Cenozoic time broke the bedrock terrane into a series of north-trending fault blocks; the uplifted mountain areas were deeply eroded and the resulting debris deposited in the adjacent basins. Most of the mineral deposits in the Pioche-Marysvale mineral belt were formed during igneous activity in middle and late Cenozoic time. The regional sampling program was designed to define broad geochemical patterns and trends which can be utilized along with geologic and geophysical data to assess the mineral resource potential for this quadrangle. These maps of the Richfield 1° x 2° quadrangle show the regional distributions of copper in two fractions of heavy-mineral concentrates of drainage sediments.

Utah↗

USGS1985

Maps showing distribution of lead in heavy-mineral concentrates, Richfield 1° x 2° quadrangle, Utah

These maps are part of a folio of maps of the Richfield 1° x 2 ° quadrangle, Utah, prepared under the Conterminuous United States Mineral Assessment Program. Other publications in this folio are listed in the selected references. Located in west-central Utah, the Richfield quadrangle covers the eastern part of the Plioche-Marysvale igneous and mineral belt, which extends from the vicinity of Plioche in southeastern Nevada east-northeastward for 250 km (155 mi) into central Utah. The western two-thirds of the Richfield quadrangle is in the Basin and Range province and the eastern third is in the High Plateaus of Utah, a subprovince of the Colorado Plateau. Bedrock in the northern part of the Richfield quadrangle consists predominantly of latest Precambrian and Paleozoic sedimentary strata that were thrust eastward during the Sevier orogeny in Cretaceous time onto an autochthon of Mesozoic sedimentary rocks in the eastern part of the quadrangle. The southern part of the quadrangle is largely underlain by Oligocene and younger volcanic rocks and related intrusions. Extensional tectonism in late Cenozoic time broke the bedrock terrane into a series of north-trending fault blocks; the uplifted mountain areas were deeply eroded and the resulting debris deposited in the adjacent basins. Most of the mineral deposits in the Pioche-Marysvale mineral belt were formed during igneous activity in middle and late Cenozoic time. The regional sampling program was designed to define broad geochemical patterns and trends which can be utilized along with geologic and geophysical data to assess the mineral resource potential for this quadrangle. These maps of the Richfield 1° x 2° quadrangle show the regional distributions of copper in two fractions of heavy-mineral concentrates of drainage sediments.

Utah↗

USGS1985

Maps showing distribution of thorium in heavy-mineral concentrates, Richfield 1° x 2° quadrangle, Utah

These maps are part of a folio of maps of the Richfield 1° x 2 ° quadrangle, Utah, prepared under the Conterminuous United States Mineral Assessment Program. Other publications in this folio are listed in the selected references. Located in west-central Utah, the Richfield quadrangle covers the eastern part of the Plioche-Marysvale igneous and mineral belt, which extends from the vicinity of Plioche in southeastern Nevada east-northeastward for 250 km (155 mi) into central Utah. The western two-thirds of the Richfield quadrangle is in the Basin and Range province and the eastern third is in the High Plateaus of Utah, a subprovince of the Colorado Plateau. Bedrock in the northern part of the Richfield quadrangle consists predominantly of latest Precambrian and Paleozoic sedimentary strata that were thrust eastward during the Sevier orogeny in Cretaceous time onto an autochthon of Mesozoic sedimentary rocks in the eastern part of the quadrangle. The southern part of the quadrangle is largely underlain by Oligocene and younger volcanic rocks and related intrusions. Extensional tectonism in late Cenozoic time broke the bedrock terrane into a series of north-trending fault blocks; the uplifted mountain areas were deeply eroded and the resulting debris deposited in the adjacent basins. Most of the mineral deposits in the Pioche-Marysvale mineral belt were formed during igneous activity in middle and late Cenozoic time. The regional sampling program was designed to define broad geochemical patterns and trends which can be utilized along with geologic and geophysical data to assess the mineral resource potential for this quadrangle. These maps of the Richfield 1° x 2° quadrangle show the regional distributions of copper in two fractions of heavy-mineral concentrates of drainage sediments.

Utah↗

USGS1985

Maps showing distribution of tin in heavy-mineral concentrates, Richfield 1° x 2° quadrangle, Utah

These maps are part of a folio of maps of the Richfield 1° x 2 ° quadrangle, Utah, prepared under the Conterminuous United States Mineral Assessment Program. Other publications in this folio are listed in the selected references. Located in west-central Utah, the Richfield quadrangle covers the eastern part of the Plioche-Marysvale igneous and mineral belt, which extends from the vicinity of Plioche in southeastern Nevada east-northeastward for 250 km (155 mi) into central Utah. The western two-thirds of the Richfield quadrangle is in the Basin and Range province and the eastern third is in the High Plateaus of Utah, a subprovince of the Colorado Plateau. Bedrock in the northern part of the Richfield quadrangle consists predominantly of latest Precambrian and Paleozoic sedimentary strata that were thrust eastward during the Sevier orogeny in Cretaceous time onto an autochthon of Mesozoic sedimentary rocks in the eastern part of the quadrangle. The southern part of the quadrangle is largely underlain by Oligocene and younger volcanic rocks and related intrusions. Extensional tectonism in late Cenozoic time broke the bedrock terrane into a series of north-trending fault blocks; the uplifted mountain areas were deeply eroded and the resulting debris deposited in the adjacent basins. Most of the mineral deposits in the Pioche-Marysvale mineral belt were formed during igneous activity in middle and late Cenozoic time. The regional sampling program was designed to define broad geochemical patterns and trends which can be utilized along with geologic and geophysical data to assess the mineral resource potential for this quadrangle. These maps of the Richfield 1° x 2° quadrangle show the regional distributions of copper in two fractions of heavy-mineral concentrates of drainage sediments.

Utah↗

USGS1985

Maps showing distribution of tungsten in heavy-mineral concentrates, Richfield 1° x 2° quadrangle, Utah

These maps are part of a folio of maps of the Richfield 1° x 2 ° quadrangle, Utah, prepared under the Conterminuous United States Mineral Assessment Program. Other publications in this folio are listed in the selected references. Located in west-central Utah, the Richfield quadrangle covers the eastern part of the Plioche-Marysvale igneous and mineral belt, which extends from the vicinity of Plioche in southeastern Nevada east-northeastward for 250 km (155 mi) into central Utah. The western two-thirds of the Richfield quadrangle is in the Basin and Range province and the eastern third is in the High Plateaus of Utah, a subprovince of the Colorado Plateau. Bedrock in the northern part of the Richfield quadrangle consists predominantly of latest Precambrian and Paleozoic sedimentary strata that were thrust eastward during the Sevier orogeny in Cretaceous time onto an autochthon of Mesozoic sedimentary rocks in the eastern part of the quadrangle. The southern part of the quadrangle is largely underlain by Oligocene and younger volcanic rocks and related intrusions. Extensional tectonism in late Cenozoic time broke the bedrock terrane into a series of north-trending fault blocks; the uplifted mountain areas were deeply eroded and the resulting debris deposited in the adjacent basins. Most of the mineral deposits in the Pioche-Marysvale mineral belt were formed during igneous activity in middle and late Cenozoic time. The regional sampling program was designed to define broad geochemical patterns and trends which can be utilized along with geologic and geophysical data to assess the mineral resource potential for this quadrangle. These maps of the Richfield 1° x 2° quadrangle show the regional distributions of copper in two fractions of heavy-mineral concentrates of drainage sediments.

Utah↗

USGS1985

Maps showing distribution of zinc in heavy-mineral concentrates, Richfield 1° by 2° quadrangle, Utah

These maps are part of a folio of maps of the Richfield 1° x 2° quadrangle, Utah, prepared under the Coterminous United States Mineral Assessment Program. Other publications in this folio are listed in the selected references. Located in west-central Utah, the Richfield quadrangle covers the eastern part of the Plioche-Marysvale igneous mineral belt, which extends from the vicinity of Plioche in southeastern Nevada east-northeastward for 250 km (155 mi) into central Utah. The western two-thirds of the Richfield quadrangle is in the Basin and Range province and the eastern third is in the High Plateaus of Utah, a subprovince of the Colorado Plateau. Bedrock in the northern part of the Richfield quadrangle consists predominantly of latest Precambrian and Paleozoic sedimentary strata that were thrust eastward during the Sevier orogeny in Cretaceous time onto an autochthon of Mesozoic sedimentary rocks in the eastern part of the quadrangle. The southern part of the quadrangle is largely underlain by Oligocene and younger volcanic rocks and related instrusions. Extensional tectonism in late Cenozoic time broke the bedrock terrane into a series of north-trending fault blocks; the uplifted mountain areas were deeply eroded and the resulting debris deposited in the adjacent basins. Most of the mineral deposits in the Pioche-Marysvale mineral belt were formed during igneous activity in middle and late Cenozoic time. The regional sampling program was designed to define broad geochemical patterns and trends which can be utilized along with geologic and geophysical data to assess the mineral resource potential for this quadrangle. These maps of the Richfield 1° x 2° quadrangle show the regional distributions of zinc in two fractions of heavy-mineral concentrates of drainage sediments.

Utah↗

USGS1988

Maps showing distribution of copper, lead, zinc, cadmium, and silver in samples of minus-60-mesh (0.25-MM) stream sediment and nonmagnetic heavy-mineral concentrate, Walker Lake 1 degree by 2 degrees Quadrangle, California and Nevada

This report is part of a folio of maps of the Walker Lake 1 o x 2 o quadrangle, California and Nevada, prepared under the Conterminous United States Mineral Assessment Program. The folio includes geological, geochemical, and geophysical maps, as well as mineral resources assessment maps, which identify selected known or possible mineral-deposit environments in the quadrangle. The geochemical maps show the distributions of selected individual elements (Chaffee and others, 1988 a, b, c) and the distributions of selected groups of elements (Chaffee, 1988a, b, c). Discussions accompanying the individual element maps are restricted to mineral residences of the individual elements as well as to what types of mineral deposits and environments may be represented by anomalies of a particular element. Discussions accompanying the multielemental maps describe the types of mineral deposits that may be related to each element group and indicate the most favorable localities for these deposits.

California, Nevada↗

USGS1988

Maps showing distribution of iron, cobalt, barium, strontium, arsenic, antimony, and bismuth in samples of minus-60-mesh (0.25-MM) stream sediment and (or) nonmagnetic heavy-mineral concentrate, Walker Lake 1 degree by 2 degrees Quadrangle, California and Nevada

This report is part of a folio of maps of the Walker Lake 1 o x 2 o quadrangle, California and Nevada, prepared under the Conterminous United States Mineral Assessment Program. The folio includes geological, geochemical, and geophysical maps, as well as mineral resources assessment maps, which identify selected known or possible mineral-deposit environments in the quadrangle. The geochemical maps show the distributions of selected individual elements (Chaffee and others, 1988 a, b, c) and the distributions of selected groups of elements (Chaffee, 1988a, b, c). Discussions accompanying the individual element maps are restricted to mineral residences of the individual elements as well as to what types of mineral deposits and environments may be represented by anomalies of a particular element. Discussions accompanying the multielemental maps describe the types of mineral deposits that may be related to each element group and indicate the most favorable localities for these deposits.

California, Nevada↗

USGS1988

Maps showing distribution of anomalies based on the use of R-mode factor analysis for selected groupings of elements in samples of minus-60-mesh (0.25-MM) stream sediment and nonmagnetic heavy-mineral concentrate, Walker Lake 1 degree by 2 degrees Quadrangle, California and Nevada

This report is part of a folio of maps of the Walker Lake 1 o x 2 o quadrangle, California and Nevada, prepared under the Conterminous United States Mineral Assessment Program. The folio includes geological, geochemical, and geophysical maps, as well as mineral resources assessment maps, which identify selected known or possible mineral-deposit environments in the quadrangle. The geochemical maps show the distributions of selected individual elements (Chaffee and others, 1988 a, b, c) and the distributions of selected groups of elements (Chaffee, 1988a, b, c). Discussions accompanying the individual element maps are restricted to mineral residences of the individual elements as well as to what types of mineral deposits and environments may be represented by anomalies of a particular element. Discussions accompanying the multielemental maps describe the types of mineral deposits that may be related to each element group and indicate the most favorable localities for these deposits.

California, Nevada↗

USGS1988

Maps showing distribution of anomalies based on the use of scoresum plots for selected groupings of elements in samples of nonmagnetic heavy-mineral concentrate, Walker Lake 1 degree by 2 degrees Quadrangle, California and Nevada

This report is part of a folio of maps of the Walker Lake 1 o x 2 o quadrangle, California and Nevada, prepared under the Conterminous United States Mineral Assessment Program. The folio includes geological, geochemical, and geophysical maps, as well as mineral resource assessment maps which identify selected known or possible mineral-deposit environments in the quadrangle. The geochemical maps show the distributioins of selected individual elements (Chaffee and others 1988a, b, c, d) and the distributions of selected groups of elements (Chaffee, 1988a, b). Discussions accompanying the individual element maps are restricted to possible mineral residences of the individual elements as well as to what types of mineral deposits and environments may be represented by anomalies of a particular element. Discussions accompanying the multielement maps describe the types of mineral deposits that may be related to each element group and indicate the most favorable localities for these deposits.

California, Nevada↗

USGS1993

Mineral resource assessment of rare-earth elements, thorium, titanium, and uranium in the Greenville 1° x 2° quadrangle, South Carolina, Georgia, and North Carolina

Mineral resources of the Greenville 1° x 2° quadrangle, South Carolina, Georgia, and North Carolina, were assessed between 1984 and 1990 under the Conterminuous United States Mineral Assessment Program (CUSMAP) of the U.S. Geological Survey (USGS). The mineral resource assessments were made on the basis of geologic, geochemical, and geophysical investigations and the presence of mines, prospects, and mineral occurrences from the literature. This report is an assessment of the rare-earth elements (REE), thorium, titanium, and uranium resources in the Greenville quadrangle and is based on heavy mineral concentrates collected in 1951-54 by the USGS (Overstreet and others, 1968; Caldwell and White, 1973; Cuppels and White, 1973); on the results of the U.S. Department of Energy, National Uranium Resource Evaluation (NURE) sampling program (Ferguson, 1978, 1979); on analyses of stream-sediment and heavy-mineral-concentrate samples (Jackson and Moore, 1992, G.C Cullin, USGS, unpub. data, 1992) on maps showing aerial gamma radiation in the Greenville quadrangle (D.L. Daniels, USGS, unpub. data, 1992); and on the geology as mapped by Nelson and others (1987, 1989).

Georgia, North Carolina, South Carolina↗

USGS2002

Progress on geoenvironmental models for selected mineral deposit types

Since the beginning of economic geology as a subdiscipline of the geological sciences, economic geologists have tended to classify mineral deposits on the basis of geological, mineralogical, and geochemical criteria, in efforts to systematize our understanding of mineral deposits as an aid to exploration. These efforts have led to classifications based on commodity, geologic setting (Cox and Singer, 1986), inferred temperatures and pressures of ore formation (Lindgren, 1933), and genetic setting (Park and MacDiarmid, 1975; Jensen and Bateman, 1979). None of these classification schemes is mutually exclusive; instead, there is considerable overlap among all of these classifications. A natural outcome of efforts to classify mineral deposits is the development of “mineral deposit models.” A mineral deposit model is a systematically arranged body of information that describes some or all of the essential characteristics of a selected group of mineral deposits; it presents a concept within which essential attributes may be distinguished and from which extraneous, coincidental features may be recognized and excluded (Barton, 1993). Barton (1993) noted that the grouping of deposits on the basis of common characteristics forms the basis for a classification, but the specification of the characteristics required for belonging to the group is the basis for a model. Models range from purely descriptive to genetic. A genetic model is superior to a descriptive model because it provides a basis to distinguish essential from extraneous attributes, and it has flexibility to accommodate variability in sources, processes, and local controls. In general, a descriptive model is a necessary prerequisite to a genetic model.

Open-File Report↗

USGS2002

Policy, a factor shaping minerals supply and demand

Valuable insights about the future availability of minerals for the U.S. economy can be gained from a study of the history of U.S. mineral development. From the beginning, first as corporate ventures, next as colonies, then as States united, American governments have pursued policies that had the effect to encourage development of mineral and other resources. During the frontier period, 1781-1890, all levels of government in the United States spent public money for infrastructure development (canals, forts, ports, railroads, roads, and other), and the Federal government was particularly active in land acquisition, land surveys, and resource title transfer to private interests. These activities were effective support for the development of the nation?s mineral resources. This was a period of rapid growth, wealth building, and substantial land disturbance. During the post-frontier period, 1891-present, the consequences of resource development helped to move values for ecology and culture to the forefront of public policy, making them more competitive with development values. To date, American history?s lesson has been that policy is very important with regard to where and how minerals are placed into the service of human needs. This is also the history of global mining, as mining capital has moved to friendly policy environments. Although policy can create regional dislocations of mining, it has had little effect on the long-term global availability of minerals at continuously decreasing prices.

Open-File Report↗

USGS2003

Preliminary metallogenic belt and mineral deposit maps for northeast Asia

The metallogenic belts and locations of major mineral deposits of Northeast Asia are portrayed on Sheets 1-4. Sheet 1 portrays the location of significant lode deposits and placer districts at a scale of 1:7,500,000. Sheets 2-4 portray the metallogenic belts of the region in a series of 12 time-slices from the Archean through the Quaternary at a scale of 1:15,000,000. For all four map sheets, a generalized geodynamics base map, derived from a more detailed map by Parfenov and others (2003), is used as an underlay for the metallogenic belt maps. This geodynamics map underlay permits depicts the major host geologic units and structures that host metallogenic belts. Four tables are included in this report. A hierarchial ranking of mineral deposit models is listed in Table 1. And summary features of lode deposits, placer districts, and metallogenic belts are described in Tables 2, 3, and 4, respectively. The metallogenic belts for Northeast Asia are synthesized, compiled, described, and interpreted with the use of modern concepts of plate tectonics, analysis of terranes and overlap assemblages, and synthesis of mineral deposit models. The data supporting the compilation are: (1) comprehensive descriptions of mineral deposits; (2) compilation and synthesis of a regional geodynamics map the region at 5 million scale with detailed explanations and cited references; and (3) compilation and synthesis of metallogenic belt maps at 15 million scale with detailed explanations and cited references. These studies are part of a major international collaborative study of the Mineral Resources, Metallogenesis, and Tectonics of Northeast Asia that is being conducted from 1997 through 2002 by geologists from earth science agencies and universities in Russia, Mongolia, Northeastern China, South Korea, Japan, and the USA. Companion studies and previous publications are: (1) a detailed geodynamics map of Northeast Asia (Parfenov and 2003); (2) a compilation of major mineral deposit models (Rodionov and Nokleberg, 2000; Rodionov and others, 2000; Obolenskiy and others, 2003); and (3) a database on significant metalliferous and selected nonmetalliferous lode deposits, and selected placer districts (Ariunbileg and others, 2003).

Open-File Report↗