Bradley, Dwight C.

About the author

U.S. Geological Survey, Western Region, Alaska area, Director's office
Abandoned mines and quarries, Antimony, Atomic absorption analysis, Atomic emission spectroscopy, Barium, Bedrock geologic units, Beryllium, Carbon, Cerium, Cobalt, Copper, Data services, Dysprosium, Economic geology, Ecosystem management, Erbium, Europium, Fluorine, Gadolinium, Gallium, Geochemistry, Geologic maps, Geologic structure, Geology, Geospatial datasets, Germanium, Hafnium, Holmium, Indium, Iridium, Lanthanide series elements, Lanthanum, Laws and regulations, Lead, Lithium, Lutetium, Manganese, Maps and atlases, Metallic mineral resources, Mine drainage, Mine waste, Mineral deposits, Mineral resources, Mineralogy, Mining and quarrying, Natural resource assessment, Natural resource exploration, Neodymium, Niobium, Nonmetallic mineral resources, Ore formation, Osmium, Palladium, Placer deposit mining, Platinum, Praseodymium, Promethium, Rare earth elements, Resource supply and demand, Rhenium, Rhodium, Risk assessment, Rocks and deposits, Ruthenium, Samarium, Scandium, Sedimentary rocks, Selenium, Silver, Study areas, Tantalum, Tellurium, Terbium, Thorium, Thulium, Tin, Titanium, Vanadium, Waste treatment and disposal, Web map services, Ytterbium, Yttrium, Zinc, Zirconium, Mineral deposit areas, Copper, Lead, Silver, Zinc, ArcInfo interchange, DBF, FileMaker, HTML table, KML, Microsoft Excel format, OGC WFS, OGC WMS, Comma-delimited text, File geodatabase (ESRI), Shapefile, Tab-delimited text, Antimony, Barite, Beryllium, Cobalt, Gallium, Germanium, Graphite (natural), Hafnium, Indium, Lithium, Manganese, Niobium, Platinum-group metals, Rare earths, Rhenium, Selenium, Tantalum, Tellurium, Tin, Titanium, Vanadium, Zirconium

A preliminary deposit model for lithium brines

This report is part of an effort by the U.S. Geological Survey to update existing mineral deposit models and to develop new ones. The global transition away from hydrocarbons toward energy alternatives increases demand for many scarce metals. Among these

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A preliminary deposit model for lithium-cesium-tantalum (LCT) pegmatites

This report is part of an effort by the U.S. Geological Survey to update existing mineral deposit models and to develop new ones. We emphasize practical aspects of pegmatite geology that might directly or indirectly help in exploration for lithium-cesium-

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Mineral evolution and Earth history

<p><span>The field of mineral evolution&mdash;a merger of mineralogy and Earth history&mdash;coalesced in 2008 with the first of several global syntheses by Robert Hazen and coworkers in the&nbsp;</span><i>American Mineralogist.</i><span>&nbsp;They showed

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Lithium

Lithium, the lightest of all metals, is used in air treatment, batteries, ceramics, glass, metallurgy, pharmaceuticals, and polymers.

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U-Pb geochronology and tectonic implications of a Silurian ash in the Farewell Terrane, Alaska

The Farewell terrane is an exotic continental fragment in interior Alaska that during the early Paleozoic was the site of a passive margin. We report a <sup>238</sup>U/<sup>206</sup>Pb zircon age of 432.9±3.0 Ma from a Farewell terrane ash in Mt. McKinle

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Geologic map of central (interior) Alaska

Geologic map and associated digital databases of central Alaska. Compilation and reinterpretation of previously published and unpublished mapping at 1:250,000 scale, with limited 1:125,000 and 1:63,360 scale mapping.

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Major- and trace-element concentrations in rock samples collected in 2006 from the Taylor mountains 1:250,000-scale quadrangle, Alaska

138 rock geochemistry samples collected during the 2006 field season were analyzed using the ICP-AES/MS42, ICP-AES10, fire assay, and cold vapor atomic absorption methods

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Compilation of mineral resource data for Mississippi Valley-Type and clastic-dominated sediment-hosted lead-zinc deposits

Global compilation of information on the sediment-hosted Pb-Zn deposits traditionally called sedimentary exhalative (SEDEX) and Mississippi Valley Type (MVT) deposits, including updated updated grade and tonnage data.

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Mineral resource data for Mississippi Valley-Type and clastic-dominated sediment-hosted lead-zinc deposits

Map interface and data download of Sed Zn-Pb data including KML and GIS data formats

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Critical Mineral Resources of the United States—An Introduction

An overview of the mineral resource classifications, terms, and definitions used in PP 1802. Includes a review of the history of the use and meaning of the term “critical” applied to minerals or materials.

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Global distribution of selected mines, deposits, and districts of critical minerals

Approximate locations and short descriptions of mines, deposits, and districts where critical minerals are found. The critical minerals are discussed in USGS Professional Paper 1802 many of these locations are described in further detail in that report.

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Selenium

Selenium is a trace element in Earth's crust. Modern uses for selenium include energy-efficient windows that limit heat transfer and thin-film photovoltaic cells that convert solar energy into electricity.

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Barite (Barium)

Barite (barium sulfate, BaSO4) is vital to the oil and gas industry because it is a key constituent of the mud used to drill oil and gas wells. Elemental barium is an additive in optical glass, ceramic glazes, and other products.

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Cobalt

Cobalt is a silvery gray metal that has diverse uses due to its ferromagnetism, hardness and wear-resistance when alloyed with other metals, low thermal and electrical conductivity, high melting point, multiple valences, and color effects with silica.

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Graphite

Steelmaking and refractory applications in metallurgy use the largest amount of produced graphite; however, emerging technology uses in large-scale fuel cell, battery, and lightweight high-strength composites promise more uses.

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Manganese

Manganese is used to make steel, where it serves as a purifying agent in iron-ore refining and as an alloy.

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Niobium and Tantalum

Niobium and tantalum are found together in nature because they have similar physical and chemical properties. Niobium is used in high-strength steel alloys, while tantalum is used in electronic capacitors.

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Rhenium

Rhenium is a rare metal that has an extremely high melting point and a heat-stable crystalline structure. It is used in high-temperature superalloys, to make turbine blades for jet aircraft engines and is a catalyst for petroleum refining.

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Tin

Tin (Sn) is one of the first metals to be used by humans. Almost without exception, tin is used as an alloy. Its major uses today are for cans and containers, construction materials, transportation materials, and solder.

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Titanium

Titanium colors paint, paper, plastic, rubber, and wallboard. Because of its strength and corrosion resistance, titanium metal and its alloys are used in the aerospace industry as well as for welding rod coatings, biological implants, and consumer goods.

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Zirconium and Hafnium

Zirconium and hafnium are corrosion-resistant metals that are widely used in the chemical and nuclear industries. Most zirconium is consumed in the form of the main ore mineral zircon or as zirconium oxide or other zirconium chemicals.

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Beryllium

Beryllium is a mineral commodity that is used in a variety of industries to make products that are essential for the smooth functioning of a modern society.

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Environmental Considerations Related to Mining of Nonfuel Minerals

A key aspect of identifying and mitigating environmental risks of mining is understanding how they vary from one deposit type to another—a concept that forms the basis for geoenvironmental mineral-deposit models.

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Fluorine

Fluorine compounds are essential in numerous chemical and manufacturing processes. Fluorspar is the commercial name for fluorite (isometric CaF2), which is the only fluorine mineral that is mined on a large scale.

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Gallium

Gallium is a soft, silvery metallic element with an atomic number of 31 and the chemical symbol Ga. Gallium is used in a wide variety of products that have microelectronic components containing either gallium arsenide (GaAs) or gallium nitride (GaN).

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Germanium and Indium

Germanium and indium are used in electronics devices, flat-panel display screens, light-emitting diodes, night vision devices, optical fiber, optical lens systems, and solar power arrays.

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Vanadium

Vanadium is used primarily in the production of steel alloys; as a catalyst for the chemical industry; in the making of ceramics, glasses, and pigments; and in vanadium redox-flow batteries (VRBs) for large-scale storage of electricity.

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GIS and data tables for focus areas for potential domestic nonfuel sources of rare earth elements

Locations of focus areas to be used for planning and collection of geophysical, geological, and topographic (lidar) data pertaining to the study of rare earth element resources in the US.

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Tellurium

Tellurium is a rare element obtained as a byproduct of mining for other commodities whose main uses are in photovoltaic solar cells and as an additive to copper, lead, and steel alloys in various types of machinery.

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Platinum-Group Elements

The platinum-group elements (PGEs)—platinum, palladium, rhodium, ruthenium, iridium, and osmium—are metals that have similar physical and chemical properties and tend to occur together in nature. PGEs are indispensable to many industrial applications.

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Rare-Earth Elements

Because of their unusual physical and chemical properties, the REEs have diverse defense, energy, industrial, and military technology applications including glass, petroleum refining, automobiles, and magnets.

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Antimony

Antimony’s leading use is as a fire retardant in safety equipment and in household goods such as mattresses. The U.S. Government has considered antimony to be a critical mineral mainly because of its use in military applications.

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