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Douglas B Yager (Former Employee)

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Filter Total Items: 33

Geophysical data provide three dimensional insights into porphyry copper systems in the Silverton caldera, Colorado, USA

The Silverton caldera in southwest Colorado, USA hosts polymetallic veins and pervasively altered rocks indicative of porphyry copper systems. Nearly a kilometer of erosion has exposed multiple levels of the hydrothermal systems from shallow lithocaps down to quartz-sericite-pyrite veins. New airborne electromagnetic and magnetic survey data are integrated with previous alteration mapping and porp
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Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center

GIS-Based Identification of Areas with Mineral Resource Potential for Six Selected Deposit Groups, Bureau of Land Management Central Yukon Planning Area, Alaska

This study, covering the Bureau of Land Management (BLM) Central Yukon Planning Area (CYPA), Alaska, was prepared to aid BLM mineral resource management planning. Estimated mineral resource potential and certainty are mapped for six selected mineral deposit groups: (1) rare earth element (REE) deposits associated with peralkaline to carbonatitic intrusive igneous rocks, (2) placer and paleoplacer
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Groundwater and Streamflow Information Program, Mineral Resources Program, Alaska Science Center, Geology, Minerals, Energy, and Geophysics Science Center, Geology, Geophysics, and Geochemistry Science Center

Geological and geophysical data for a three-dimensional view—Inside the San Juan and Silverton Calderas, Southern Rocky Mountains Volcanic Field, Silverton, Colorado

IntroductionThe San Juan-Silverton caldera complex located near Silverton, Colorado, in the Southern Rocky Mountains volcanic field is an ideal natural laboratory for furthering the understanding of shallow-to-deep volcanic-related mineral systems. Recent advances in geophysical data processing and three-dimensional (3D) model construction will help to characterize shallow properties important for
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Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center

Potash—A vital agricultural nutrient sourced from geologic deposits

This report summarizes the primary sources of potash in the United States. Potash is an essential nutrient that, along with phosphorus and nitrogen, is used as fertilizer for growing crops. Plants require sufficient potash to activate enzymes, which in turn catalyze chemical reactions important for water uptake and photosynthesis. When potassium is available in quantities necessary for healthy pla
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Energy and Minerals, Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center

Geology and mineral resources of the North-Central Montana Sagebrush Focal Area: Chapter D in Mineral resources of the Sagebrush Focal Areas of Idaho, Montana, Nevada, Oregon, Utah, and Wyoming

SummaryThe U.S. Department of the Interior has proposed to withdraw approximately 10 million acres of Federal lands from mineral entry (subject to valid existing rights) from 12 million acres of lands defined as Sagebrush Focal Areas (SFAs) in Idaho, Montana, Nevada, Oregon, Utah, and Wyoming (for further discussion on the lands involved see Scientific Investigations Report 2016–5089–A). The purpo
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Energy and Minerals, Energy Resources Program, Mineral Resources Program, National Laboratories Program, Science and Decisions Center, Geology, Energy & Minerals Science Center, Geology, Minerals, Energy, and Geophysics Science Center, Geology, Geophysics, and Geochemistry Science Center, National Minerals Information Center

Geology and mineral resources of the Southwestern and South-Central Wyoming Sagebrush Focal Area, Wyoming, and the Bear River Watershed Sagebrush Focal Area, Wyoming and Utah: Chapter E in Mineral resources of the Sagebrush Focal Areas of Idaho, Monta

SummaryThe U.S. Department of the Interior has proposed to withdraw approximately 10 million acres of Federal lands from mineral entry (subject to valid existing rights) from 12 million acres of lands defined as Sagebrush Focal Areas (SFAs) in Idaho, Montana, Nevada, Oregon, Utah, and Wyoming (for further discussion on the lands involved see Scientific Investigations Report 2016–5089–A). The purpo
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Energy and Minerals, Energy Resources Program, Mineral Resources Program, National Laboratories Program, Science and Decisions Center, Geology, Minerals, Energy, and Geophysics Science Center, Geology, Geophysics, and Geochemistry Science Center, National Minerals Information Center

Geology and mineral resources of the Sheldon-Hart Mountain National Wildlife Refuge Complex (Oregon and Nevada), the Southeastern Oregon and North-Central Nevada, and the Southern Idaho and Northern Nevada (and Utah) Sagebrush Focal Areas: Chapter B in

SummaryThe U.S. Department of the Interior has proposed to withdraw approximately 10 million acres of Federal lands from mineral entry (subject to valid existing rights) from 12 million acres of lands defined as Sagebrush Focal Areas (SFAs) in Idaho, Montana, Nevada, Oregon, Utah, and Wyoming (for further discussion on the lands involved see Scientific Investigations Report 2016–5089–A). The purpo
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Energy and Minerals, Energy Resources Program, Mineral Resources Program, National Laboratories Program, Science and Decisions Center, Geology, Minerals, Energy, and Geophysics Science Center, Geology, Geophysics, and Geochemistry Science Center, National Minerals Information Center

Use of mineral/solution equilibrium calculations to assess the potential for carnotite precipitation from groundwater in the Texas Panhandle, USA

This study investigated the potential for the uranium mineral carnotite (K2(UO2)2(VO4)2·3H2O) to precipitate from evaporating groundwater in the Texas Panhandle region of the United States. The evolution of groundwater chemistry during evaporation was modeled with the USGS geochemical code PHREEQC using water-quality data from 100 groundwater wells downloaded from the USGS National Water Informati
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Ecosystems, Toxic Substances Hydrology, Environmental Health Program, Geology, Geophysics, and Geochemistry Science Center

The geochemical atlas of Alaska, 2016

A rich legacy of geochemical data produced since the early 1960s covers the great expanse of Alaska; careful treatment of such data may provide significant and revealing geochemical maps that may be used for landscape geochemistry, mineral resource exploration, and geoenvironmental investigations over large areas. To maximize the spatial density and extent of data coverage for statewide mapping of
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Energy and Minerals, Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center, Alaska Science Center

New perspectives on a 140-year legacy of mining and abandoned mine cleanup in the San Juan Mountains, Colorado

The Gold King mine water release that occurred on 5 August 2015 near the historical mining community of Silverton, Colorado, highlights the environmental legacy that abandoned mines have on the environment. During reclamation efforts, a breach of collapsed workings at the Gold King mine sent 3 million gallons of acidic and metal-rich mine water into the upper Animas River, a tributary to the Color
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Energy and Minerals, Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center

A GIS and statistical approach to identify variables that control water quality in hydrothermally altered and mineralized watersheds, Silverton, Colorado, USA

Hydrothermally altered bedrock in the Silverton mining area, southwest Colorado, USA, contains sulfide minerals that weather to produce acidic and metal-rich leachate that is toxic to aquatic life. This study utilized a geographic information system (GIS) and statistical approach to identify watershed-scale geologic variables in the Silverton area that influence water quality. GIS analysis of mine
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Geology, Geophysics, and Geochemistry Science Center

Miscellaneous geochemical data from waters in the Upper Animas River Watershed, Colorado

This report releases geochemistry data in waters from the upper Animas River watershed that have been analyzed by inductively coupled plasma–mass spectrometry. These samples were collected at various sites and at various dates (41 sites and 86 samples from 2008 to 2010). A main data table is provided and the text discusses the sampling methods and locations in relation to other published reports.
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Geology, Minerals, Energy, and Geophysics Science Center, Geology, Geophysics, and Geochemistry Science Center
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Red Mountain CO

A Shallow to Deep View Inside the Hydrothermally Altered and Mineralized Silverton Caldera Complex: New Geologic Insights Gained From Modern Geophysical Interpretations

The Silverton caldera complex in southwest Colorado hosts base and precious metals that have been mined since the late 1800s. Extensive mine workings, excellent bedrock exposures, and deeply incised drainages make this area a natural laboratory ideally suited for furthering our understanding of the mineral systems in a volcanic environment. In addition, state-of-the-art geophysical data processing...
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Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center
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A Shallow to Deep View Inside the Hydrothermally Altered and Mineralized Silverton Caldera Complex: New Geologic Insights Gained From Modern Geophysical Interpretations

The Silverton caldera complex in southwest Colorado hosts base and precious metals that have been mined since the late 1800s. Extensive mine workings, excellent bedrock exposures, and deeply incised drainages make this area a natural laboratory ideally suited for furthering our understanding of the mineral systems in a volcanic environment. In addition, state-of-the-art geophysical data processing...
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Microscopic view of Saint Peter frac sand

Nonmetallic Industrial Mineral Resources of the U.S.

In 2012, this project initiated a multi-year effort to characterize domestic nonmetallic industrial mineral resources that are important for national infrastructure, agriculture, and energy development. Activities included (1) a national-scale compilation of production data, providing a snapshot of the nonmetallic industrial mineral deposits that were of significance through the 20th century and...
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Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center
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Nonmetallic Industrial Mineral Resources of the U.S.

In 2012, this project initiated a multi-year effort to characterize domestic nonmetallic industrial mineral resources that are important for national infrastructure, agriculture, and energy development. Activities included (1) a national-scale compilation of production data, providing a snapshot of the nonmetallic industrial mineral deposits that were of significance through the 20th century and...
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Airborne electromagnetic and magnetic survey data, Silverton, Colorado, 2019

Airborne electromagnetic (AEM) and magnetic survey data were collected during April and May 2019 along 1,467 line-kilometers in the San Juan-Silverton Caldera complex, Colorado, in the Southern Rocky Mountain Volcanic Field. Data were acquired by Geotech, Ltd. with the versatile time-domain electromagnetic (VTEM-ET) system together with a Geometrics optically pumped cesium vapor magnetometer. The
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Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center

Magnetic susceptibility measurements on hydrothermally altered rocks in the Silverton caldera, southwest Colorado

The U.S. Geological Survey (USGS) collected magnetic susceptibility measurements on rock outcrops to help understand causative sources of magnetic survey anomalies in the Silverton caldera region, southwest Colorado. A total of 1,400 measurements of magnetic susceptibility from 87 locations have been conducted on Paleogene volcanic and plutonic rocks that have been hydrothermally altered. Magnetic
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Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center

Magnetotelluric sounding data in the Silverton Caldera complex, Colorado, 2018

This data release includes magnetotelluric (MT) sounding data collected in July 2018 in the Silverton Caldera complex, Colorado, in the Southern Rocky Mountain Volcanic Field, by the U.S. Geological Survey (USGS). Along with geologic mapping, airborne magnetics, airborne electromagnetics, and audiomagnetotellurics, the USGS collected MT data at 22 sites along four profiles ranging from 3 to 6 kilo
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Geology, Geophysics, and Geochemistry Science Center

Audiomagnetotelluric sounding data in the Silverton Caldera complex, Colorado, 2019

This dataset includes audiomagnetotelluric (AMT) sounding data collected in July 2019 in the Silverton Caldera complex, Colorado, in the Southern Rocky Mountain Volcanic Field, by the U.S. Geological Survey (USGS). Along with geologic mapping, airborne magnetics, airborne electromagnetics, and magnetotellurics, the USGS collected AMT data at 26 sites along five profiles ranging from 2 to 5 kilomet
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Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center

Magnetotelluric sounding data in the Silverton Caldera complex, Colorado, 2019

This dataset includes magnetotelluric (MT) sounding data collected in July 2019 in the Silverton Caldera complex, Colorado, in the Southern Rocky Mountain Volcanic Field, by the U.S. Geological Survey (USGS). Along with geologic mapping, airborne magnetics, airborne electromagnetics, and audiomagnetotellurics, the USGS collected MT data at 24 sites along five profiles ranging from 2 to 5 kilometer
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Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center

Airborne electromagnetic and magnetic survey data of the San Juan-Silverton Caldera complex, Silverton, Colorado, 2019

Airborne electromagnetic (AEM) and magnetic survey data were collected during April and May 2019 along 1,467 line-kilometers in the San Juan-Silverton Caldera complex, Colorado, in the Southern Rocky Mountain Volcanic Field. Data were acquired by Geotech, Ltd. with the versatile time-domain electromagnetic (VTEM) system together with a Geometrics optically pumped cesium vapor magnetometer. The sur
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Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center

High resolution helicopter-borne magnetic and electromagnetic survey Eureka Graben area, Colorado September 1999

On September 25, 1998, SIAL Gosciences Inc. (SIAL) was awarded Department of Interior, contract 98CRCN1018, by the U.S. Geological Survey. This contract required SIAL to carry out a high-sensitivity magnetic and electromagnetic helicopter survey over one block located in the Eureka Graben Area near Silverton, Colorado. The primary goal of this project was to provide digitally recorded and processe
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Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center

Data Supporting The Geochemical Atlas of Alaska, 2016

A rich legacy of geochemical data produced since the early 1960s covers the great expanse of Alaska, and there are significant opportunities for applying this information. To maximize the spatial density and extent of data coverage for statewide mapping of element distributions, we compiled and integrated analyses of more than 175,000 sediment and soil samples from three major, separate sources:
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Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center
Filter Total Items: 18

Alteration Map Showing Major Faults and Veins and Associated Water-Quality Signatures of the Animas River Watershed Headwaters Near Silverton, Southwest Colorado

This map was produced to provide hard-copy and digital data for alteration assemblages in the historical mining area centered on the Tertiary San Juan and Silverton calderas. The data have direct application to geoenvironmental and mineral exploration objectives. This dataset represents alteration mapping for the upper Animas River watershed near Silverton, Colorado. The map is based on detaile

Map showing antimony concentrations from stream sediments and soils throughout the Humboldt River basin and surrounding areas, northern Nevada

No abstract available.
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Geology, Geophysics, and Geochemistry Science Center, Geology, Energy & Minerals Science Center

Map showing gold concentrations from stream sediments and soils throughout the Humboldt River basin and surrounding areas, northern Nevada

No abstract available.

Map showing selenium concentrations from stream sediments and soils throughout the Humboldt River basin and surrounding areas, northern Nevada

No abstract available.

Ferricrete, manganocrete, and bog iron occurrences with selected sedge bogs and active iron bogs and springs in the upper Animas River watershed, San Juan County, Colorado

During 1996 to 2000, the Bureau of Land Management, National Park Service, Environmental Protection Agency, United States Department of Agriculture (USDA) Forest Service, and the U.S. Geological Survey (USGS) developed a coordinated strategy to (1) study the environmental effects of historical mining on Federal lands, and (2) remediate contaminated s
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Ecosystems, Toxic Substances Hydrology, Environmental Health Program

Map showing arsenic concentrations from stream sediments and soils throughout the Humboldt River basin and surrounding areas, northern Nevada

No abstract available.
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Geology, Geophysics, and Geochemistry Science Center, Geology, Energy & Minerals Science Center

Map showing zinc concentrations from stream sediments and soils throughout the Humboldt River basin and surrounding areas, northern Nevada

No abstract available.
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Geology, Geophysics, and Geochemistry Science Center, Geology, Energy & Minerals Science Center

Map showing copper concentrations from stream sediments and soils throughout the Humboldt River basin and surrounding areas, northern Nevada

No abstract available.

Map showing nickel concentrations from stream sediments and soils throughout the Humboldt River basin and surrounding areas, northern Nevada

No abstract available.
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Geology, Geophysics, and Geochemistry Science Center, Geology, Energy & Minerals Science Center

Map showing lead concentrations from stream sediments and soils throughout the Humboldt River basin and surrounding areas, northern Nevada

No abstract available.

Map showing iron concentrations from stream sediments and soils throughout the Humboldt River basin and surrounding areas, northern Nevada

No abstract available.
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Geology, Geophysics, and Geochemistry Science Center, Geology, Energy & Minerals Science Center

Map showing cobalt concentrations from stream sediments and soils throughout the Humboldt River basin and surrounding areas, northern Nevada

No abstract available.
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Geology, Geophysics, and Geochemistry Science Center, Geology, Energy & Minerals Science Center
Moab, Utah, Potash In Situ Solution Mining and Solar Evaporation
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Ross Basin, Colorado
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Image: Ferricrete Formation at Base of Cement Creek
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Image: Ross basin, upper Cement Creek in Watershed above North Fork Cement Creek
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Image: Panorama of Silverton, Colorado
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Image: Brown's Gulch Below Brooklyn Mine near Silverton, Colorado
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Image: Cement Creek Following Storm Event
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USGS April 2 Open House in Silverton Colorado Well Received

On April 2, the USGS hosted an Open House in Silverton, Colorado, about planned airborne geophysical surveys in the Silverton region.

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Potash Cache: USGS Study Summarizes U.S. Sources of an Essential Nutrient for Agriculture

A new USGS report summarizes the primary sources of potash in the United States. Potash is an essential nutrient that, along with phosphorus and...

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