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The growth in the use of Geographic Information Systems (GIS) has highlighted the need for regional and national digital geologic maps attributed with age and lithology information. Such maps can be conveniently used to generate derivative maps for purposes including mineral-resource assessment, metallogenic studies, tectonic studies, and environmental research. This Open-File Report is a preliminary version of part of a series of integrated state geologic map databases that cover the entire United States.The only national-scale digital geologic maps that portray most or all of the United States for the conterminous U.S. are the digital version of the King and Beikman (1974a, b) map at a scale of 1:2,500,000, as...
Categories: Publication; Types: Citation; Tags: Open-File Report
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This is a report of geochemical data from various media collected on Isle Royale, a large island in northeastern Lake Superior. Isle Royale became a national park in 1940 and was designated as a wilderness area in 1976.USGS sampling began in 1996 as part of a larger project on the Midcontinent Rift in the Lake Superior region. Data are given in nine Microsoft Excel spreadsheets. All the data are newly acquired by the USGS.
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Magmatic sulfide deposits containing nickel (Ni) and copper (Cu), with or without (?) platinum-group elements (PGEs), account for approximately 60 percent of the world's Ni production and are active exploration targets in the United States and elsewhere. On the basis of their principal metal production, magmatic sulfide deposits in mafic rocks can be divided into two major types: those that are sulfide-rich, typically with 10 to 90 percent sulfide minerals, and have economic value primarily because of their Ni and Cu contents; and those that are sulfide-poor, typically with 0.5 to 5 percent sulfide minerals, and are exploited principally for PGE. Because the purpose of this deposit model is to facilitate the assessment...
Categories: Publication; Types: Citation; Tags: Open-File Report
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This field trip examines the geology of rocks of the Keweenawan Supergroup (1 .1 Ga) and related intrusive rocks of the Midcontinent rift system (MRS) in the western part of the northern peninsula of Michigan. The combination of stops includes all formations of the Keweenawan Supergroup in this region. Examination of all described localities requires more than a single day and participants are encouraged to use this guidebook on their own to supplement the localities that will be visited on our one-day trip. Because of uncertainties of weather, road conditions, and remaining snow pack in early May in this region of very heavy snowfall, the stops that we will visitwill not be known until the date of the trip. Stops...
Categories: Publication; Types: Citation
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The growth in the use of Geographic Information Systems (GIS) has highlighted the need for regional and national digital geologic maps attributed with age and rock type information. Such spatial data can be conveniently used to generate derivative maps for purposes that include mineral-resource assessment, metallogenic studies, tectonic studies, human health and environmental research.In 1997, the United States Geological Survey’s Mineral Resources Program initiated an effort to develop national digital databases for use in mineral resource and environmental assessments. One primary activity of this effort was to compile a national digital geologic map database, utilizing state geologic maps, to support mineral...
Categories: Publication; Types: Citation; Tags: Open-File Report
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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...
Categories: Publication; Types: Citation; Tags: Open-File Report
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The growth in the use of Geographic Information Systems (GIS) has highlighted the need for regional and national digital geologic maps attributed with age and lithology information. Such maps can be conveniently used to generate derivative maps for purposes including mineral-resource assessment, metallogenic studies, tectonic studies, and environmental research. This Open-File Report is a preliminary version of part of a series of integrated state geologic map databases that cover the entire United States.The only national-scale digital geologic maps that portray most or all of the United States for the conterminous U.S. are the digital version of the King and Beikman (1974a, b) map at a scale of 1:2,500,000, as...
Categories: Publication; Types: Citation; Tags: Open-File Report
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In 1998 the U.S. Geological Survey (USGS) initiated a study to examine the natural regional environmental impact of sulfide mineralization exposed to episodic weathering and glaciation. The study focused on the Bend copper-gold massive sulfide deposit located in the Medford District of the Chequamegon National Forest in north central Wisconsin. The Bend massive sulfide deposit is a small, metal-rich sulfide body hosted by Paleoproterozoic metavolcanics. The mineralized horizon subcrops beneath 100-120 feet of glacial cover, and consists of massive pyrite and other sulfides. Bedrock and ore geochemistry are well characterized by analyses of diamond drill core provided to the USGS by Sharpe Energy and Resources. In...
Categories: Publication; Types: Citation; Tags: Open-File Report
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This report presents the results of the USGS Mineral Resources Program activity to compile a national-scale geologic map database to support national and regional level projects, including mineral resource and geoenvironmental assessments. The only comprehensive sources of regional- and national-scale geologic maps are state geologic maps with scales ranging from 1:100,000 to 1:1,000,000. Digital versions of these state maps form the core of what is presented here. Because no adequate geologic map exists for the state of Alaska, it is being compiled in regional blocks that also form part of this national database. It is expected that this series will completed by approximately the end of 2007. These maps and databases...
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The growth in the use of Geographic nformation Systems (GS) has highlighted the need for regional and national digital geologic maps attributed with age and rock type information. Such spatial data can be conveniently used to generate derivative maps for purposes that include mineral-resource assessment, metallogenic studies, tectonic studies, human health and environmental research. n 1997, the United States Geological Survey’s Mineral Resources Program initiated an effort to develop national digital databases for use in mineral resource and environmental assessments. One primary activity of this effort was to compile a national digital geologic map database, utilizing state geologic maps, to support mineral...
Categories: Publication; Types: Citation
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This descriptive model for magmatic iron-titanium-oxide (Fe-Ti-oxide) deposits hosted by Proterozoic age massif-type anorthosite and related rock types presents their geological, mineralogical, geochemical, and geoenvironmental attributes. Although these Proterozoic rocks are found worldwide, the majority of known deposits are found within exposed rocks of the Grenville Province, stretching from southwestern United States through eastern Canada; its extension into Norway is termed the Rogaland Anorthosite Province. This type of Fe-Ti-oxide deposit dominated by ilmenite rarely contains more than 300 million tons of ore, with between 10- to 45-percent titanium dioxide (TiO2), 32- to 45-percent iron oxide (FeO), and...
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This descriptive model for magmatic iron-titanium-oxide (Fe-Ti-oxide) deposits hosted by Proterozoic age massif-type anorthosite and related rock types presents their geological, mineralogical, geochemical, and geoenvironmental attributes. Although these Proterozoic rocks are found worldwide, the majority of known deposits are found within exposed rocks of the Grenville Province, stretching from southwestern United States through eastern Canada; its extension into Norway is termed the Rogaland Anorthosite Province. This type of Fe-Ti-oxide deposit dominated by ilmenite rarely contains more than 300 million tons of ore, with between 10- to 45-percent titanium dioxide (TiO2), 32- to 45-percent iron oxide (FeO), and...
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The area of this data set includes the classic geology and mineral deposits of the Keweenaw Peninsula, renowned for the occurrence of great volumes of Middle Proterozoic flood basalts and the world's largest concentration of native copper. Native copper was mined there continuously from the 1840's to the 1960's. For the earlier part of that period the Keweenawan native copper district was the principal source of copper for the United States.
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The growth in the use of Geographic Information Systems (GIS) has highlighted the need for regional and national digital geologic maps attributed with age and lithology information. Such maps can be conveniently used to generate derivative maps for purposes including mineral-resource assessment, metallogenic studies, tectonic studies, and environmental research. This Open-File Report is a preliminary version of part of a series of integrated state geologic map databases that cover the entire United States.The only national-scale digital geologic maps that portray most or all of the United States for the conterminous U.S. are the digital version of the King and Beikman (1974a, b) map at a scale of 1:2,500,000, as...
Categories: Publication; Types: Citation; Tags: Open-File Report
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The Rough Mountain Roadless Area comprises about 9,300 acres of George Washington National Forest land in the Valley and Ridge province in west-central Virginia. The area, which is about 6 mi long and 2 mi wide, is in Bath and Alleghany Counties, about 3 mi south of Millboro Springs, Va. (Index Map). State Route 42 forms part of the western boundary of the area, the Cowpasture River forms part of the southern boundary and the Chesapeake and Ohio Railroad and Pads Creek form the eastern boundary. The northern boundary follows the crests of two small ridges that lead east and west from the main ridgeline of Rough Mountain.
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Magmatic sulfide deposits containing nickel (Ni) and copper (Cu), with or without (±) platinum-group elements (PGE), account for approximately 60 percent of the world’s nickel production. Most of the remainder of the Ni production is derived from lateritic deposits, which form by weathering of ultramafic rocks in humid tropical conditions. Magmatic Ni-Cu±PGE sulfide deposits are spatially and genetically related to bodies of mafic and/or ultramafic rocks. The sulfide deposits form when the mantle-derived mafic and/or ultramafic magmas become sulfide-saturated and segregate immiscible sulfide liquid, commonly following interaction with continental crustal rocks. Deposits of magmatic Ni-Cu sulfides occur with mafic...
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Isle Royale National Park, Michigan, is a large island in northeastern Lake Superior that became a national park in 1940 and was designated as a wilderness area in 1976. The relative isolation of Isle Royale (Figure 1), 25 kilometers out in Lake Superior from the Canadian mainland, its generally harsh climate, and its status as a wilderness national park have minimized human influence on the geochemical evolution of its landscape. USGS sampling on Isle Royale began in 1996 as part of a larger project on the geology of the Midcontinent rift in the Lake Superior region and continued through 2000. Sampling began with collecting bedrock samples to characterize the geochemistry of the volcanic rocks that make up the...
Categories: Publication; Types: Citation; Tags: Open-File Report


map background search result map search result map A deposit model for magmatic iron-titanium-oxide deposits related to Proterozoic massif anorthosite plutonic suites Bedrock, soil, and lichen geochemistry from Isle Royale National Park, Michigan Geology and Mineral Deposits of the Keweenaw Peninsula and Vicinity, Michigan Geology of Keweenawan Supergroup Rocks near the Porcupine Mountains, Ontonagon and Gogebic Counties, Michigan A deposit model for magmatic iron-titanium-oxide deposits related to Proterozoic massif anorthosite plutonic suites: Chapter K in <i>Mineral Deposit Models for Resource Assessment</i> Preliminary Integrated Geologic Map Databases for West Virginia Bedrock, soil, and lichen geochemistry from Isle Royale National Park, Michigan Geology and Mineral Deposits of the Keweenaw Peninsula and Vicinity, Michigan Preliminary Integrated Geologic Map Databases for West Virginia Geology of Keweenawan Supergroup Rocks near the Porcupine Mountains, Ontonagon and Gogebic Counties, Michigan A deposit model for magmatic iron-titanium-oxide deposits related to Proterozoic massif anorthosite plutonic suites A deposit model for magmatic iron-titanium-oxide deposits related to Proterozoic massif anorthosite plutonic suites: Chapter K in <i>Mineral Deposit Models for Resource Assessment</i>