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Bradley S. Van Gosen

Publications and source records attributed to Bradley S. Van Gosen.

At least 55 records · Page 3Linked to original sources
USGS2011

Reported historic asbestos mines, historic asbestos prospects, and other natural occurrences of asbestos in California

The map (Plate.pdf), pamphlet (Pamphlet.pdf), and the accompanying datasets in this report provide information for 290 sites in California where asbestos occurs in natural settings, using descriptions found in the geologic literature. Data on location, mineralogy, geology, and relevant literature for each asbestos site are provided. Using the map and digital data in this report, the user can examine the distribution of previously reported asbestos and their geological characteristics in California. This report is part of an ongoing study by the U.S. Geological Survey to identify and map sites where asbestos mineralization occurs in the United States, which includes similar maps and datasets of natural asbestos localities within the Eastern United States (http://pubs.usgs.gov/of/2005/1189/), the Central United States (http://pubs.usgs.gov/of/2006/1211/), the Rocky Mountain States (http://pubs.usgs.gov/of/2007/1182/), the Southwestern United States (http://pubs.usgs.gov/of/2008/1095/), and the Northwestern United States (Oregon and Washington) (http://pubs.usgs.gov/of/2010/1041/). These reports are intended to provide State and local government agencies and other stakeholders with geologic information on reported asbestos mineralization in the United States.

California↗
USGS2011

Carbonatite and alkaline intrusion-related rare earth element deposits–A deposit model

The rare earth elements are not as rare in nature as their name implies, but economic deposits with these elements are not common and few deposits have been large producers. In the past 25 years, demand for rare earth elements has increased dramatically because of their wide and diverse use in high-technology applications. Yet, presently the global production and supply of rare earth elements come from only a few sources. China produces more than 95 percent of the world's supply of rare earth elements. Because of China's decision to restrict exports of these elements, the price of rare earth elements has increased and industrial countries are concerned about supply shortages. As a result, understanding the distribution and origin of rare earth elements deposits, and identifying and quantifying our nation's rare earth elements resources have become priorities. Carbonatite and alkaline intrusive complexes, as well as their weathering products, are the primary sources of rare earth elements. The general mineral deposit model summarized here is part of an effort by the U.S. Geological Survey's Mineral Resources Program to update existing models and develop new descriptive mineral deposit models to supplement previously published models for use in mineral-resource and mineral-environmental assessments. Carbonatite and alkaline intrusion-related REE deposits are discussed together because of their spatial association, common enrichment in incompatible elements, and similarities in genesis. A wide variety of commodities have been exploited from carbonatites and alkaline igneous rocks, such as rare earth elements, niobium, phosphate, titanium, vermiculite, barite, fluorite, copper, calcite, and zirconium. Other enrichments include manganese, strontium, tantalum, thorium, vanadium, and uranium.

Open-File Report↗
USGS2011

Data report for the geologic and scenic quality evaluation of selected sand and gravel sites on the Wind River Indian Reservation, Wyoming

In April 2005, the U.S. Geological Survey (USGS) conducted field studies on the Wind River Indian Reservation, Wyoming, to inventory and evaluate sand and gravel deposits underlying river terraces on tribal lands along the Wind River. This report contains the results for 12 sites of sand and gravel deposits evaluated for their potential use as aggregate in Portland cement concrete, asphalt, and base course. The report provides the results of: * The USGS geologic studies and engineering tests. * A conclusion and recommendation for the best use of sand and gravel materials. * Calculations of available sand and gravel materials. * A scenic quality landscape inventory and evaluation.

Wyoming↗
USGS2010

The dispersion of fibrous amphiboles by glacial processes in the area surrounding Libby, Montana, USA

Mining operations began at a world-class vermiculite deposit at Vermiculite Mountain near Libby, Montana, circa 1920 and ended in 1990. Fibrous and asbestiform amphiboles intergrown with vermiculite ore are suspected to be a causative factor in an abnormally high number of cases of respiratory diseases in former mine and mill workers, and in residents of Libby. The question addressed in this report is whether some of the amphibole from Vermiculite Mountain could have been dispersed by Pleistocene glacial processes rather than by human activity after vermiculite mining began. The history of Pinedale glaciation in the Libby area provides a framework for estimating the presence and distribution of asbestiform amphiboles derived from Vermiculite Mountain and found in naturally occurring sediments of Glacial Lake Kootenai that underlie the Libby Valley area. There were two situations where sediments derived from Vermiculite Mountain were deposited into Glacial Lake Kootenai: (1) as lake-bottom sediments derived from meltwater flowing down Rainy Creek when the valley south of Vermiculite Mountain was free of ice but active ice still covered Vermiculite Mountain; and (2) as lake-bottom sediments eroded from the Rainy Creek outwash and re-deposited during a re-advance of the Purcell Trench Glacier lobe near Moyie Springs, Idaho.

Montana↗
USGS2010

Reported Historic Asbestos Mines, Historic Asbestos Prospects, and Other Natural Occurrences of Asbestos in Oregon and Washington

This map and its accompanying dataset provide information for 51 natural occurrences of asbestos in Washington and Oregon, using descriptions found in the geologic literature. Data on location, mineralogy, geology, and relevant literature for each asbestos site are provided. Using the map and digital data in this report, the user can examine the distribution of previously reported asbestos occurrences and their geological characteristics in the Pacific Northwest States of Washington and Oregon. This report is part of an ongoing study by the U.S. Geological Survey to identify and map reported natural asbestos occurrences in the United States, which thus far includes similar maps and datasets of natural asbestos occurrences within the Eastern United States (http://pubs.usgs.gov/of/2005/1189/), the Central United States (http://pubs.usgs.gov/of/2006/1211/), the Rocky Mountain States (http://pubs.usgs.gov/of/2007/1182/), and the Southwestern United States (http://pubs.usgs.gov/of/2008/1095/). These reports are intended to provide State and local government agencies and other stakeholders with geologic information on natural occurrences of asbestos in the United States.

Open-File Report↗
USGS2010

Examination of Libby, Montana, Fill Material for Background Levels of Amphibole from the Rainy Creek Complex Using Scanning Electron Microscopy and X-Ray Microanalysis

Natural background levels of Libby-type amphibole in the sediment of the Libby valley in Montana have not, up to this point, been determined. The purpose of this report is to provide the preliminary findings of a study designed by both the U.S. Geological Survey and the U.S. Environmental Protection Agency and performed by the U.S. Geological Survey. The study worked to constrain the natural background levels of fibrous amphiboles potentially derived from the nearby Rainy Creek Complex. The material selected for this study was sampled from three localities, two of which are active open-pit sand and gravel mines. Seventy samples were collected in total and examined using a scanning electron microscope equipped with an energy dispersive x-ray spectrometer. All samples contained varying amounts of feldspars, ilmenite, magnetite, quartz, clay minerals, pyroxene minerals, and non-fibrous amphiboles such as tremolite, actinolite, and magnesiohornblende. Of the 70 samples collected, only three had detectable levels of fibrous amphiboles compatible with those found in the rainy creek complex. The maximum concentration, identified here, of the amphiboles potentially from the Rainy Creek Complex is 0.083 percent by weight.

Open-File Report↗
USGS2010

Chemistry of selected core samples, concentrate, tailings, and tailings pond waters: Pea Ridge iron (-lanthanide-gold) deposit, Washington County, Missouri

The Minerals at Risk and for Emerging Technologies Project of the U.S. Geological Survey (USGS) Mineral Resources Program is examining potential sources of lanthanide elements (rare earth elements) as part of its objective to provide up-to-date geologic information regarding mineral commodities likely to have increased demand in the near term. As part of the examination effort, a short visit was made to the Pea Ridge iron (-lanthanide-gold) deposit, Washington County, Missouri in October 2008. The deposit, currently owned by Wings Enterprises, Inc. of St. Louis, Missouri (Wings), contains concentrations of lanthanides that may be economic as a primary product or as a byproduct of iron ore production. This report tabulates the results of chemical analyses of the Pea Ridge samples and compares rare earth elements contents for world class lanthanide deposits with those of the Pea Ridge deposit. The data presented for the Pea Ridge deposit are preliminary and include some company data that have not been verified by the USGS or by the Missouri Department of Natural Resources, Division of Geology and Land Survey (DGLS), Geological Survey Program (MGS). The inclusion of company data is for comparative purposes only and does not imply an endorsement by either the USGS or MGS.

Missouri↗
USGS2010

Processes of Terrace Formation on the Piedmont of the Santa Cruz River Valley During Quaternary Time, Green Valley-Tubac Area, Southeastern Arizona

In this report we describe a series of stepped Quaternary terraces on some piedmont tributaries of the Santa Cruz River valley in southeastern Arizona. These terraces began to form in early Pleistocene time, after major basin-and-range faulting ceased, with lateral planation of basin fill and deposition of thin fans of alluvium. At the end of this cycle of erosion and deposition, tributaries of the Santa Cruz River began the process of dissection and terrace formation that continues to the present. Vertical cutting alternated with periods of equilibrium, during which streams cut laterally and left thin deposits of channel fill. The distribution of terraces was mapped and compiled with adjacent mapping to produce a regional picture of piedmont stream history in the middle part of the Santa Cruz River valley. For selected tributaries, the thickness of terrace fill was measured, particle size and lithology of gravel were determined, and sedimentary features were photographed and described. Mapping of terrace stratigraphy revealed that on two tributaries, Madera Canyon Wash and Montosa Canyon Wash, stream piracy has played an important role in piedmont landscape development. On two other tributaries, Cottonwood Canyon Wash and Josephine Canyon Wash, rapid downcutting preempted piracy. Two types of terraces are recognized: erosional and depositional. Gravel in thin erosional terraces has Trask sorting coefficients and sedimentary structures typical of streamflood deposits, replete with bar-and-swale surface topography on young terraces. Erosional-terrace fill represents the channel fill of the stream that cuts the terrace; the thickness of the fill indicates the depth of channel scour. In contrast to erosional terraces, depositional terraces show evidence of repeated deposition and net aggradation, as indicated by their thickness (as much as 20+ m) and weakly bedded structure. Depositional terraces are common below mountain-front canyon mouths where streams drop their load in response to abrupt flattening of gradients and expansion of channel banks, and they extend down the piedmont along Josephine Canyon Wash. Gravel in depositional terraces also has sorting coefficients typical of streamflood deposits. Sedimentary features in both types of terraces are consistent with deposition by flash floods in ephemeral streams, suggesting the climate was arid. Bedding and clast armor are weakly developed, clast clusters and imbrication are common, and crossbedding is generally absent. Debris-flow deposits, even near the mountain front, are surprisingly rare. On the tectonically stable piedmont of southeastern Arizona, stream piracy and climate change are the most likely agents of terrace formation. Both piracy and climate change can cause rapid changes in discharge and sediment supply, which initiate cycles of incision, lateral cutting, and aggradation. Increased stream discharge initiates downcutting, but increased sediment supply interrupts downcutting and causes streams to cut laterally and aggrade. At times, on Madera Canyon Wash and Montosa Canyon Wash, stream piracy affected stream discharge and sediment supply, but on Cottonwood Canyon Wash and Josephine Canyon Wash, only climate change could have initiated terrace cutting. Terraces probably formed during extended arid intervals when sparse vegetation and flashy stream discharge combined to increase sediment supply. In most cases, sediment supply was sufficient to promote lateral cutting but not long-term aggradation. Thus, most streams formed erosional terraces. The middle Pleistocene Josephine Canyon Wash formed a depositional terrace because it had a source of abundant unconsolidated sediment.

Scientific Investigations Report↗
USGS2010

The principal rare earth elements deposits of the United States: A summary of domestic deposits and a global perspective

The rare earth elements (REE) are fifteen elements with atomic numbers 57 through 71, from lanthanum to lutetium ('lanthanides'), plus yttrium (39), which is chemically similar to the lanthanide elements and thus typically included with the rare earth elements. Although industrial demand for these elements is relatively small in tonnage terms, they are essential for a diverse and expanding array of high-technology applications. REE-containing magnets, metal alloys for batteries and light-weight structures, and phosphors are essential for many current and emerging alternative energy technologies, such as electric vehicles, energy-efficient lighting, and wind power. REE are also critical for a number of key defense systems and other advanced materials. Section 843 of the National Defense Authorization Act for Fiscal Year 2010, Public Law 111-84, directs the Comptroller General to complete a report on REE materials in the defense supply chain. The Office of Industrial Policy, in collaboration with other U.S. Government agencies, has initiated (in addition to this report) a detailed study of REE. This latter study will assess the Department of Defense's use of REE, as well as the status and security of domestic and global supply chains. That study will also address vulnerabilities in the supply chain and recommend ways to mitigate any potential risks of supply disruption. To help conduct this study, the Office of Industrial Policy asked the U.S. Geological Survey (USGS) to report on domestic REE reserves and resources in a global context. To this end, the enclosed report is the initial USGS contribution to assessing and summarizing the domestic REE resources in a global perspective. In 2009, the Mineral Resources Program of the USGS organized a new project under the title Minerals at Risk and For Emerging Technologies in order to evaluate mineral resource and supply issues of rare metals that are of increasing importance to the national economy. Leaders and members of this project, with the assistance of the USGS National Minerals Information Center, prepared the enclosed USGS report on domestic REE resources. The USGS Mineral Resources Program has investigated domestic and selected foreign REE resources for many decades, and this report summarizes what has been learned from this research. The USGS National Minerals Information Center (formerly Minerals Information Team) has monitored global production, trade, and resources for an equally long period and is the principal source of statistics used in this report. The objective of this study is to provide a nontechnical overview of domestic reserves and resources of REE and possibilities for utilizing those resources. At the present time, the United States obtains its REE raw materials from foreign sources, almost exclusively from China. Import dependence upon a single country raises serious issues of supply security. In a global context, domestic REE resources are modest and of uncertain value; hence, available resources in traditional trading partners (such as Canada and Australia) are of great interest for diversifying sources of supply. This report restates basic geologic facts about REE relevant to assessing security of supply, followed by a review of current United States consumption and imports of REE, current knowledge of domestic resources, and possibilities for future domestic production. Further detail follows in a deposit-by-deposit review of the most significant domestic REE deposits (see index map). Necessary steps to develop domestic resources are discussed in a separate section, leading into a review of current domestic exploration and a discussion of the value of a future national mineral resource assessment of REE. The report also includes an overview of known global REE resources and discusses the reliability of alternative foreign sources of REE.

Scientific Investigations Report↗
USGS2009

Thorium deposits of the United States — Energy resources for the future?

Many nations are exploring new ways to meet their growing energy supply needs, with a particular focus upon methods that produce lower carbon dioxide emissions compared to traditional oil, natural gas, and coal power plants. As a result, thorium-based nuclear power has experienced renewed attention as a potential energy source. Thus, it benefits the United States and other countries to identify and evaluate their indigenous thorium resources. This report describes the geology and resources of the principal thorium districts of the United States.

Circular↗
USGS2009

The Iron Hill (Powderhorn) carbonatite complex, Gunnison County, Colorado — A potential source of several uncommon mineral resources

A similar version of this slide show was presented on three occasions during 2008: two times to local chapters of the Society for Mining, Metallurgy, and Exploration (SME), as part of SME's Henry Krumb lecture series, and the third time at the Northwest Mining Association's 114th Annual Meeting, held December 1-5, 2008, in Sparks (Reno), Nevada. In 2006, the U.S. Geological Survey (USGS) initiated a study of the diverse and uncommon mineral resources associated with carbonatites and associated alkaline igneous rocks. Most of these deposit types have not been studied by the USGS during the last 25 years, and many of these mineral resources have important applications in modern technology. The author chose to begin this study at Iron Hill in southwestern Colorado because it is the site of a classic carbonatite complex, which is thought to host the largest known resources of titanium and niobium in the United States.

Colorado↗
USGS2009

Geophysical delineation of Mg-rich ultramafic rocks for mineral carbon sequestration

This presentation covers three general topics: (1) description of a new geologic compilation of the United States that shows the location of magnesium-rich ultramafic rocks in the conterminous United States; (2) conceptual illustration of the potential ways that ultramafic rocks could be used to sequester carbon dioxide; and (3) description of ways to use geophysical data to refine and extend the geologic mapping of ultramafic rocks and to better characterize their mineralogy. The geophysical focus of this research is twofold. First, we illustrate how airborne magnetic data can be used to map the shallow subsurface geometry of ultramafic rocks for the purpose of estimating the volume of rock material available for mineral CO 2 sequestration. Secondly, we explore, on a regional to outcrop scale, how magnetic mineralogy, as expressed in magnetic anomalies, may vary with magnesium minerals, which are the primary minerals of interest for CO 2 sequestration.

Open-File Report↗
USGS2008

Relational database for the geology of the northern Rocky Mountains— Idaho, Montana, and Washington

A relational database was created to prepare and organize geologic map-unit and lithologic descriptions for input into a spatial database for the geology of the northern Rocky Mountains, a compilation of forty-three geologic maps for parts of Idaho, Montana, and Washington in U.S. Geological Survey Open File Report 2005-1235. Not all of the information was transferred to and incorporated in the spatial database due to physical file limitations. This report releases that part of the relational database that was completed for that earlier product. In addition to descriptive geologic information for the northern Rocky Mountains region, the relational database contains a substantial bibliography of geologic literature for the area. The relational database nrgeo.mdb (linked below) is available in Microsoft Access version 2000, a proprietary database program. The relational database contains data tables and other tables used to define terms, relationships between the data tables, and hierarchical relationships in the data; forms used to enter data; and queries used to extract data.

Idaho, Montana, Washington↗
USGS2008

Reported Historic Asbestos Mines, Historic Asbestos Prospects, and Natural Asbestos Occurrences in the Southwestern United States (Arizona, Nevada, and Utah)

This map and its accompanying dataset provide information for 113 natural asbestos occurrences in the Southwestern United States (U.S.), using descriptions found in the geologic literature. Data on location, mineralogy, geology, and relevant literature for each asbestos site are provided. Using the map and digital data in this report, the user can examine the distribution of previously reported asbestos occurrences and their geological characteristics in the Southwestern U.S., which includes sites in Arizona, Nevada, and Utah. This report is part of an ongoing study by the U.S. Geological Survey to identify and map reported natural asbestos occurrences in the U.S., which thus far includes similar maps and datasets of natural asbestos occurrences within the Eastern U.S. (http://pubs.usgs.gov/of/2005/1189/), the Central U.S. (http://pubs.usgs.gov/of/2006/1211/), and the Rocky Mountain States (http://pubs.usgs.gov/of/2007/1182/. These reports are intended to provide State and local government agencies and other stakeholders with geologic information on natural occurrences of asbestos in the U.S.

Open-File Report↗
USGS2008

Geochemistry of Rock Samples Collected from the Iron Hill Carbonatite Complex, Gunnison County, Colorado

A study conducted in 2006 by the U.S. Geological Survey collected 57 surface rock samples from nine types of intrusive rock in the Iron Hill carbonatite complex. This intrusive complex, located in Gunnison County of southwestern Colorado, is known for its classic carbonatite-alkaline igneous geology and petrology. The Iron Hill complex is also noteworthy for its diverse mineral resources, including enrichments in titanium, rare earth elements, thorium, niobium (columbium), and vanadium. This study was performed to reexamine the chemistry and metallic content of the major rock units of the Iron Hill complex by using modern analytical techniques, while providing a broader suite of elements than the earlier published studies. The report contains the geochemical analyses of the samples in tabular and digital spreadsheet format, providing the analytical results for 55 major and trace elements.

Open-File Report↗
USGS2007

A compilation of spatial digital databases for selected U.S. Geological Survey nonfuel mineral resource assessments for parts of Idaho and Montana

This report compiles selected results from 13 U.S. Geological Survey (USGS) mineral resource assessment studies conducted in Idaho and Montana into consistent spatial databases that can be used in a geographic information system. The 183 spatial databases represent areas of mineral potential delineated in these studies and include attributes on mineral deposit type, level of mineral potential, certainty, and a reference. The assessments were conducted for five 1? x 2? quadrangles (Butte, Challis, Choteau, Dillon, and Wallace), several U.S. Forest Service (USFS) National Forests (including Challis, Custer, Gallatin, Helena, and Payette), and one Bureau of Land Management (BLM) Resource Area (Dillon). The data contained in the spatial databases are based on published information: no new interpretations are made. This digital compilation is part of an ongoing effort to provide mineral resource information formatted for use in spatial analysis. In particular, this is one of several reports prepared to address USFS needs for science information as forest management plans are revised in the Northern Rocky Mountains.

Open-File Report↗
USGS2007

Reported Historic Asbestos Mines, Historic Asbestos Prospects, and Natural Asbestos Occurrences in the Rocky Mountain States of the United States (Colorado, Idaho, Montana, New Mexico, and Wyoming)

This map and its accompanying dataset provide information for 48 natural asbestos occurrences in the Rocky Mountain States of the United States (U.S.), using descriptions found in the geologic literature. Data on location, mineralogy, geology, and relevant literature for each asbestos site are provided. Using the map and digital data in this report, the user can examine the distribution of previously reported asbestos occurrences and their geological characteristics in the Rocky Mountain States. This report is part of an ongoing study by the U.S. Geological Survey to identify and map reported natural asbestos occurrences in the U.S., which thus far includes similar maps and datasets of natural asbestos occurrences within the Eastern U.S. (http://pubs.usgs.gov/of/2005/1189/) and the Central U.S. (http://pubs.usgs.gov/of/2006/1211/). These reports are intended to provide State and local government agencies and other stakeholders with geologic information on natural occurrences of asbestos in the U.S.

Open-File Report↗