Denver Microbeam Laboratory: Mineral Resources Research Support
Science Center Objects
The USGS Denver Microbeam Laboratory provides chemical analysis and characterization of rocks, minerals, and environmental samples in support of a wide variety of USGS projects related to mineral resources, including research projects funded by the USGS Mineral Resources Program. The research applications for these projects range from mineral resource research and assessments, to geologic mapping and geochronology, to geologic hazards and radioactive waste disposal, to the environment and human health.
Additional Information
For additional information on the laboratory facilities and equipment, visit the Denver Microbeam Laboratory site.
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Date published: August 21, 2020Status: ActiveIsotope and Chemical Methods for Mineral and Geoenvironmental Assessments and Support of USGS Science Strategy
This Project integrates several geochemical tools—stable isotope geochemistry, noble gas geochemistry, active gas geochemistry, single fluid inclusion chemistry, and fluid inclusion solute chemistry—in studies of the processes that form mineral deposits and the processes that disrupt them during mining or natural weathering. Research is directed toward fundamental scientific questions or, in...
Contacts: Craig A Johnson, Ph.D. -
Date published: August 20, 2020Status: ActiveNational Geochemical Database
The National Geochemical Database project assembles, reformats, corrects, and archives historical data obtained from the geochemical analysis of millions of geologic samples collected for USGS studies. These data, representing hundreds of millions of dollars' worth of USGS research, are provided to USGS researchers; other Federal agencies; State Geological Surveys and Environmental Protection...
Contacts: Steven M Smith -
Date published: August 3, 2020Status: ActiveNon-Traditional Stable Isotopes
Understanding the genesis of ore deposits and their behavior in the environment is a subject of great importance to the Nation. A relatively new tool to aid in these efforts to investigate the origin and environmental effects of ore deposits is the use of "heavy" metal stable isotopes. Our research objectives are to utilize various isotopic systems to advance our understanding of ore genesis...
Contacts: Philip L Verplanck -
Date published: July 31, 2020Status: ActiveIntegrated Hyperspectral, Geophysical and Geochemical Studies of Yellowstone National Park Hydrothermal Systems
We are researching the subsurface groundwater flow systems in Yellowstone and the relation of these systems to understanding the regional movement of water in a volcanic center. New geophysical data will be integrated with existing data sets from hyperspectral data from Yellowstone's thermal areas and thermal water geochemistry to help define regionally extensive mineral assemblages, the...
Contacts: JoAnn Holloway -
Date published: July 31, 2020Status: ActiveDevelopment of USGS Geochemical Reference Materials
The project focus will be the development of traditional and microanalytical reference materials that support USGS geochemical investigations. Development of new microanalytical reference materials allows USGS scientists and outside customers to examine a greater range of sample types while maintaining a high degree of data reliability.
Contacts: Stephen A Wilson, Justin Birdwell -
Date published: June 19, 2020Status: ActiveCritical Elements in Carbonatites: From Exploration Targets to Element Distribution
Critical elements are essential to the modern economy and have potential supply chain disruptions, but compared to most base and precious metals, little work has been done in understanding ore-grade enrichments. Carbonatites are the primary source of the worlds light rare earth elements and niobium, and a potential source for heavy rare earths, scandium, tantalum, and thorium. Project...
Contacts: Philip L Verplanck -
Date published: May 29, 2020Status: ActiveArgon Geochronology
This project supports the USGS argon geochronology laboratory in Denver. The USGS 40Ar/39Ar geochronology laboratory is a state-of-the-art research facility for determining absolute ages of minerals and rocks. The 40Ar/39Ar laboratory contributes critical geochronology to individual USGS research projects and to partners in academia and other Federal...
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Date published: September 30, 2019Status: CompletedSediment-Hosted Copper Deposits in the Lake Superior Portion of the Midcontinent Rift System
This project is focused on the sediment-hosted copper deposits of the Midcontinent Rift, with three main objectives: 1) describe the ore mineralogy and geochemistry of the White Pine and Copperwood deposits, 2) evaluate whether hydrothermal alteration in footwall rocks can be used as a vector towards ore, and 3) provide a careful scoping study to evaluate whether unconventional platinum-group...
Contacts: Jeffrey L Mauk, Timothy Hayes -
Date published: November 6, 2018Status: ActiveIntegrated Uranium Resource and Environmental Assessment
The US Geological Survey has assembled a small group of scientists who are assessing the uranium resource potential of the United States. Uranium is used to fuel the 98 operable nuclear reactors in the United States, providing 20% of the nation’s electricity. More than 95% of this uranium is imported, and the rest is produced from uranium mines in Wyoming, Nebraska and Texas and a uranium...
Contacts: Susan M Hall -
Date published: September 28, 2018Status: CompletedTrace Metal Mobility in the Yellow Pine Mining District, Idaho
The study objective is to conduct an integrated, interdisciplinary study on source areas, biogeochemical transformations, and physical and biological pathways for trace metal transport in a tributary of the Snake River watershed, focusing on the Sugar Creek watershed. The historical Cinnabar mercury mine site is at the headwaters of Cinnabar Creek, a tributary to Sugar Creek. This integrated...
The complexity of mudstone diagenesis - some insight from the Tøyen Formation, Lower to Middle Ordovician, southern Sweden
The Lower to Middle Ordovician Tøyen Shale in southern Sweden, a biostratigraphically well-dated siliciclastic mudstone unit, shows 18 distinct authigenic cements that include sulfides, carbonates, silicates, clays, and phosphates. Marcasite, sphalerite, galena, and six texturally distinct types of pyrite characterize the sulfides whereas only one...
Egenhoff, Sven; Fishman, Neil; Lowers, Heather A.; Ahlberg, Per Geochemistry of hematite veins in IOA-IOCG deposits of SE Missouri, USA: Relation to felsic magmatism and caldera lakes
The paragenesis, textures, and chemical compositions of secondary hematite in regional potassic altered rhyolites, four IOA deposits, the sedimentary iron deposit at Pilot Knob and the Boss IOCG deposit in SE Missouri were determined and compared to primary magnetite from the IOA and IOCG deposits. Magnetite is composed of elements characteristics...
Meighan, Corey J.; Hofstra, Albert H.; Marsh, Erin E.; Lowers, Heather A.; Koenig, Alan Absence of magnetite microlites, geochemistry of magnetite veins and replacements in IOA deposits, SE Missouri, USA: Relations to intermediate intrusions
The paragenesis, textures, and chemical compositions of magnetite in two mafic to intermediate intrusions and four IOA deposits in SE Missouri were studied to discriminate between igneous and hydrothermal sources. In this study, we found that replacement magnetite with mineral inclusion-rich cores yields erroneously high Ti, Al, Si, Mg, and Mn...
Meighan, Corey J.; Hofstra, Albert H.; Adams, David; Marsh, Erin E.; Lowers, Heather A.; Koenig, Alan Method to characterize inorganic particulates in lung tissue biopsies using field emission scanning electron microscopy
Humans accumulate large numbers of inorganic particles in their lungs over a lifetime. Whether this causes or contributes to debilitating disease over a normal lifespan depends on the type and concentration of the particles. We developed and tested a protocol for in situ characterization of the types and distribution of inorganic...
Lowers, Heather A.; Breit, George N.; Strand, Matthew; Pillers, Renee M.; Meeker, Gregory P.; Todorov, Todor I.; Plumlee, Geoffrey S.; Wolf, Ruth E.; Robinson, Maura; Parr, Jane; Miller, Robert J.; Groshong, Steve; Green, Francis; Rose, Cecile Characterizing the source of potentially asbestos-bearing commercial vermiculite insulation using in situ IR spectroscopy
Commercially produced vermiculite insulation from Libby, Montana, contains trace levels of asbestiform amphibole, which is known to cause asbestos-related diseases. When vermiculite insulation is found in a building, evaluation for its potential asbestos content traditionally involves collecting a sample from an attic or wall and submitting it for...
Swayze, Gregg A.; Lowers, Heather A.; Benzel, William M.; Clark, Roger N.; Driscoll, Rhonda L.; Perlman, Zac S.; Hoefen, Todd M.; Dyar, M. Darby Geochemistry and mineralogy of the Dotson Zone HREE deposit in the Bokan Mountain peralkaline igneous complex, southeastern Alaska, USA
The Bokan Mountain igneous complex (BMIC) is a typical example of a peralkaline intrusive system that has evolved to the point of developing late stage HFSE- and REE-rich silicic pegmatites and dikes. The Dotson Zone comprises a series of felsic dikes that extend from the southeast margin of the composite pluton and may represent an important...
Taylor, Cliff D.; Lowers, Heather A.; Adams, David; Robinson, R. James
USGS Spectral Library Version 7
We have assembled a library of spectra measured with laboratory, field, and airborne spectrometers. The instruments used cover wavelengths from the ultraviolet to the far infrared (0.2 to 200 microns [μm]). Laboratory samples of specific minerals, plants, chemical compounds, and manmade materials were measured. In many cases, samples were purified...
Kokaly, Raymond F.; Clark, Roger N.; Swayze, Gregg A.; Livo, K. Eric; Hoefen, Todd M.; Pearson, Neil C.; Wise, Richard A.; Benzel, William M.; Lowers, Heather A.; Driscoll, Rhonda L.; Klein, Anna J. Mineral thermometry and fluid inclusion studies of the Pea Ridge iron oxide-apatite–rare earth element deposit, Mesoproterozoic St. Francois Mountains Terrane, southeast Missouri, USA
Mineral thermometry and fluid inclusion studies were conducted on variably altered and mineralized samples from the Mesoproterozoic Pea Ridge iron oxide-apatite (IOA)-rare earth element (REE) deposit in order to constrain P-T conditions, fluid chemistry, and the source of salt and volatiles during early magnetite and later REE mineralization....
Hofstra, Albert H.; Meighan, Corey J.; Song, Xinyu; Samson, Iain; Marsh, Erin E.; Lowers, Heather A.; Emsbo, Poul; Hunt, Andrew G.
Hydrogeologic investigations of the Miocene Nogales Formation in the Nogales Area, Upper Santa Cruz Basin, Arizona
Hydrogeologic investigations were conducted to evaluate the groundwater resource potential for the Miocene Nogales Formation in the Nogales area, southern Arizona. Results indicate that parts of the formation may provide new, deeper sources of groundwater for the area. Geologic mapping determined the hydrogeologic framework of the formation by...
Page, William R.; Gray, Floyd; Bultman, Mark W.; Menges, Christopher M.
Developing integrated methods to address complex resource and environmental issues
IntroductionThis circular provides an overview of selected activities that were conducted within the U.S. Geological Survey (USGS) Integrated Methods Development Project, an interdisciplinary project designed to develop new tools and conduct innovative research requiring integration of geologic, geophysical, geochemical, and remote-sensing...
Smith, Kathleen S.; Phillips, Jeffrey D.; McCafferty, Anne E.; Clark, Roger N. The distribution and composition of REE-bearing minerals in placers of the Atlantic and Gulf coastal plains, USA
Rare earth element (REE) resources are currently of great interest because of their importance as raw materials for high-technology manufacturing. The REE-phosphates monazite (light REE enriched) and xenotime (heavy REE enriched) resist weathering and can accumulate in placer deposits as part of the heavy mineral assemblage. The Atlantic and Gulf...
Bern, Carleton R.; Shah, Anjana K.; Benzel, William M.; Lowers, Heather A. Ore mineralogy and textural zonation in the world-class epithermal Waihi Vein System, Hauraki Goldfield
The Waihi district in the Hauraki Goldfield of New Zealand contains adularia-sericite epithermal gold-silver veins that have produced more than 7.7 Moz gold. The outermost veins of the district (Martha, Favona, Moonlight, and Cowshed) contain abundant colloform, cherty, and black quartz fill textures, with minor crustiform and massive quartz. The...
Mauk, Jeffrey L.; Skinner, Erin G; Fyfe, Sarah J; Menzies, Andrew H; Lowers, Heather A.; Koenig, Alan E.-
Date published: August 14, 2020Geochemical and mineralogical analyses of uranium ores from the Hack II and Pigeon deposits, solution-collapse breccia pipes, Grand Canyon region, Mohave and Coconino Counties, Arizona, USA
This data release compiles the whole-rock geochemistry, X-ray diffraction, and electron microscopy analyses of samples collected from the uranium ore bodies of two mined-out deposits in the Grand Canyon region of northwestern Arizona - the Hack II and Pigeon deposits. The samples are grab samples of ore collected underground at each mine by the U.S. Geological Survey (USGS) during the mid
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Date published: August 4, 2020
Table of electron probe microanalyses of native copper and sulfide minerals from the White Pine sediment-hosted copper deposit, Michigan
This data release provides electron microprobe geochemical data that was collected as part of a scoping study to evaluate whether unconventional critical element resources may be associated with sediment-hosted copper systems in the Midcontinent Rift. We report abundances of trace elements in native copper and sulfide minerals in 12 thin sections from samples of the Mesoproterozoic lower...
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Date published: June 30, 2020
Tables of electron probe microanalyses from the Copperwood sediment-hosted stratiform copper deposit, Michigan, USA
This data release provides electron microprobe analyses of ore minerals from the Copperwood sediment-hosted stratiform copper deposit in the Upper Peninsula of Michigan. The minerals include bornite, chalcocite, native copper, native silver, and pyrite. Minerals were analyzed for Ag, As, Co, Cu, Fe, Hg, Ni, Pb, S, Sb, and Zn. Results with acceptable totals that lie bet
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Date published: January 6, 2020
Table of Electron Probe Microanalyses of Cassiterite from the Sullivan Pb-Zn-Ag Deposit, British Columbia
This dataset contains results from electron microprobe analyses of cassiterite from the Sullivan Pb-Zn-Ag deposit, British Columbia. These data were collected from two samples and may not reflect the overall variability present at the deposit. An ASCII text file of results is provided in comma-separated by value (csv) format. The file has the name “2019-07-09_Sullivan_Cassiterite%
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Date published: October 16, 2019
Data Dictionary for Electron Microprobe Data Collected with Probe for EPMA Software Package Developed by Probe Software
This data dictionary describes most of the possible output options given in the Probe for EPMA software package developed by Probe Software. Examples of the data output options include sample identification, analytical conditions, elemental weight percents, atomic percents, detection limits, and stage coordinates. Many more options are available and the data that is output will depen
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Date published: September 12, 2018
Lung Bioassay of Ground Dwelling Mammals from the Grand Canyon Uranium Breccia Pipe Region Using Scanning Electron Microscopy
Small mammal lung tissue sections were examined to help assess the effects of weathering on bioavailability and toxicity from sites in different phases of the mine cycle within the Grand Canyon area. Hematoxylin and eosin slides of lung tissue from brush mouse, deer mice, and pocket gophers were examined by a veterinary pathologist who marked areas of the tissue that showed normal, inflamm...
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Date published: July 5, 2018
In situ geochemical data related to the gold-quartz veins of Grass Valley, California, 2014-2015
In situ geochemical data were obtained for pyrite crystals and native gold from two distinct vein sets in the Grass Valley gold district, California. Samples of the N-S (north-south-trending) veins were collected underground at the Empire Mine State Historic Park and samples of the E-W (east-west-trending) veins were collected from drill core provided by the Idaho-Maryland Mining Corpor
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Date published: January 24, 2018
Spectroscopy of Expanded Vermiculite Products and Insulation
This dataset contains descriptions and analytical data (i.e., electron microprobe, X-ray diffraction, spectral reflectance, and scanning electron microprobe analyses) for unexpanded and expanded vermiculite samples. These data are provided for 52 samples of vermiculite attic insulation, horticultural products, aggregate, and packing materials derived from mines near Enoree, So
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Date published: April 6, 2017
USGS Spectral Library Version 7 Data
This data release provides the U.S. Geological Survey (USGS) Spectral Library Version 7 and all related documents. The library contains spectra measured with laboratory, field, and airborne spectrometers. The instruments used cover wavelengths from the ultraviolet to the far infrared (0.2 to 200 microns). Laboratory samples of specific minerals, plants, chemical compounds, and m
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Date published: November 16, 2016
Particulate Matter Identification in Lung Tissue from Deployers, Positive, and Negative controls Using Scanning Electron Microscopy and Energy Dispersive Spectroscopy (2013-2016)
We developed and tested a new method for in situ characterization and distribution of inorganic particles in biopsied lung tissue from three diverse human subject groups using field emission scanning electron microscopy with an energy dispersive analyzer. Backscattered electron and secondary electron images of particulate matter in lung tissue were acquired. Inorganic particulate matter in the...
Microscopic Gold and Lead Particles
Microscopic gold and lead particles surrounded by organic and phosphorus-rich material in a municipal biosolids sample (combined surface topography and atomic weight images).
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Date published: October 1, 2017New Uranium Mineral Named for USGS Scientist
Everyone’s seen the news–scientists discover a new species of fly and name it for Beyonce; scientists discover a new species of monkey and auction its name off; etc. Hundreds of new species of animals, plants, and other organisms are discovered and named every year. But did you know that dozens of minerals are discovered every year too?
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Date published: April 6, 2017How an Electron Microprobe Helps Find Minerals (and Makes Pretty Pictures!)
Today’s high-end electronics increasingly rely on mineral commodities...and research into those mineral commodities is increasingly using high-end electronics too!