Heather A Lowers
Heather Lowers is a Research Geologist with the Geology, Geophysics, and Geochemistry Science Center.
Science and Products
Spectroscopy of Expanded Vermiculite Products and Insulation
Electron Probe Microanalyses of apatite, rutile, and titanite from stream sediment and rock samples in the eastern Tanacross quadrangle, eastern Alaska
Table of Electron Probe Microanalyses of Native Copper and Sulfide Minerals from the White Pine Sediment-hosted Copper Deposit, Michigan
Table of Electron Probe Microanalyses of Cassiterite from the Sullivan Pb-Zn-Ag Deposit, British Columbia
Mineralogical analyses of drill core samples from the Canyon uranium-copper deposit, a solution-collapse breccia pipe, Grand Canyon area, Coconino County, Arizona, USA
Geochemical 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
Tables of electron probe microanalyses from the Copperwood sediment-hosted stratiform copper deposit, Michigan, USA
Data Dictionary for Electron Microprobe Data Collected with Probe for EPMA Software Package Developed by Probe Software
Lung Bioassay of Ground Dwelling Mammals from the Grand Canyon Uranium Breccia Pipe Region Using Scanning Electron Microscopy
In situ geochemical data related to the gold-quartz veins of Grass Valley, California, 2014-2015
Particulate Matter Identification in Lung Tissue from Deployers, Positive, and Negative controls Using Scanning Electron Microscopy and Energy Dispersive Spectroscopy (2013-2016)
USGS Spectral Library Version 7 Data
Demonstration of a novel quantitative microscopy technique for automated characterization of in situ particulate matter in coal miners with progressive massive fibrosis
The dynamic floor of Yellowstone Lake, Wyoming, USA: The last 14 k.y. of hydrothermal explosions, venting, doming, and faulting
Petrogenesis and rare earth element mineralization of the Elk Creek carbonatite, Nebraska, USA
Pathology and mineralogy demonstrate respirable crystalline silica is a major cause of severe pneumoconiosis in US coal miners
Approach for quantifying rare Earth elements at low keV
The challenges of analyzing bastnaesite (REECO3F) and hydroxylbastnaesite (REECO3OH) include beam sensitivity, quantification of light elements in a heavy element matrix, the presence of elements that cannot be analyzed with EPMA (H), and the use of x-ray lines whose physical constants are not well known. To overcome some of these challenges, Ca, La, Ce, Pr, Nd, and Sm were analyzed at 15 keV acce
Pyritization history in the middle to upper Cambrian Alum Shale, Scania Sweden: Evidence for ongoing diagenetic processes
The complexity of mudstone diagenesis - some insight from the Tøyen Formation, Lower to Middle Ordovician, southern Sweden
Absence of magnetite microlites, geochemistry of magnetite veins and replacements in IOA deposits, SE Missouri, USA: Relations to intermediate intrusions
Geochemistry of hematite veins in IOA-IOCG deposits of SE Missouri, USA: Relation to felsic magmatism and caldera lakes
Method to characterize inorganic particulates in lung tissue biopsies using field emission scanning electron microscopy
Characterizing the source of potentially asbestos-bearing commercial vermiculite insulation using in situ IR spectroscopy
Geochemistry and mineralogy of the Dotson Zone HREE deposit in the Bokan Mountain peralkaline igneous complex, southeastern Alaska, USA
Science and Products
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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, South Carolina; Libby,Electron Probe Microanalyses of apatite, rutile, and titanite from stream sediment and rock samples in the eastern Tanacross quadrangle, eastern Alaska
The exploration for porphyry deposits in some parts of Alaska may require unconventional exploration geochemical methods, depending on type of cover. The Taurus deposit and others in the region are mostly concealed by residual soils that in part include ash and loess, and therefore traditional stream sediment samples typically contain subdued geochemical signatures. Indicator mineral studies incluTable 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 NonesuchTable 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".Mineralogical analyses of drill core samples from the Canyon uranium-copper deposit, a solution-collapse breccia pipe, Grand Canyon area, Coconino County, Arizona, USA
This data release compiles the X-ray diffraction and electron microscopy analyses of drill core samples collected by the U.S. Geological Survey that were selected to typify the uranium-copper ore bodies of the Canyon deposit. The deposit is hosted by a solution-collapse breccia pipe, in which mineralization exists from about 650 to 2,100 ft (200 to 640 m) below the surface (Mathisen and others, 20Geochemical 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-1980s, wTables 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 between 98.5 and 101.5% show thaData 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 depend upon the endLung 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, inflammation, bIn 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 veins were collected underground at the Empire Mine State Historic Park and samples of the E-W veins were collected from drill core provided by the Idaho-Maryland Mining Corporation in 2008. These geochemical data were analyzed toParticulate 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 of the types 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 mattUSGS 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 man-made materials w - Multimedia
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Demonstration of a novel quantitative microscopy technique for automated characterization of in situ particulate matter in coal miners with progressive massive fibrosis
Rationale: Increasing exposure to respirable crystalline silica (RCS) linked to changes in mining production processes has been implicated in the resurgence of severe lung disease in U.S. coal miners. Lung mineralogy can provide insight into particle pathogenesis. However, standard approaches to characterizing in situ particulate matter (PM) by pulmonary pathologists have poor inter-rater comparabAuthorsJeremy T. Hua, Lauren M. Zell-Baran, L. H. Go, Carlyne D. Cool, Heather A. Lowers, K. S. Almberg, Emily A. Sarver, Susan M. Majka, Kathy D. Pang, R. A. Cohen, Cecil S. RoseThe dynamic floor of Yellowstone Lake, Wyoming, USA: The last 14 k.y. of hydrothermal explosions, venting, doming, and faulting
Hydrothermal explosions are significant potential hazards in Yellowstone National Park, Wyoming, USA. The northern Yellowstone Lake area hosts the three largest hydrothermal explosion craters known on Earth empowered by the highest heat flow values in Yellowstone and active seismicity and deformation. Geological and geochemical studies of eighteen sublacustrine cores provide the first detailed synAuthorsLisa Ann Morgan Morzel, Wayne (Pat) Shanks, Kenneth L. Pierce, Nels Iverson, Christopher Schiller, Sabrina R. Brown, Petra Zahajska, Rosine Cartier, Ron Cash, James Best, Cathy Whitlock, Sherilyn Fritz, William Benzel, Heather A. Lowers, D. A. Lovalvo, J. M. LicciardiPetrogenesis and rare earth element mineralization of the Elk Creek carbonatite, Nebraska, USA
Although carbonatites are the primary source of the world’s rare earth elements (REEs), the processes responsible for ore-grade REE enrichment in carbonatites are still poorly understood. In this study, we present a petrologic, geochemical, and isotopic evaluation of the Elk Creek carbonatite in southeast Nebraska to constrain the origin of REE mineralization. The Elk Creek carbonatite is a multilAuthorsPhilip Verplanck, G. Lang Farmer, Richard M. Kettler, Heather A. Lowers, Craig A. Johnson, Alan E. Koenig, Michael J. BlessingtonPathology and mineralogy demonstrate respirable crystalline silica is a major cause of severe pneumoconiosis in US coal miners
Rationale: The reasons for resurgent coal workers’ pneumoconiosis and its most severe forms, rapidly progressive pneumoconiosis and progressive massive fibrosis (PMF), in the United States (US) are not yet fully understood. Objective: To compare the pathologic and mineralogic features of contemporary coal miners suffering severe pneumoconiosis to their historical counterparts. Methods: Lung patholAuthorsR. A. Cohen, Cecil S. Rose, L. H. Go, Lauren M. Zell-Baran, K. S. Almberg, Emily A. Sarver, Heather A. Lowers, C. Iwaniuk, S. Clingerman, D. Richardson, J.L. Abraham, Carlyne D. Cool, A. Franko, A.F. Hubbs, J. D. Murray, M.S. Orandle, S. Sanyal, N.I. Vorajee, E.L. Petsonk, R. Zulfikar, F.H. GreenApproach for quantifying rare Earth elements at low keV
The challenges of analyzing bastnaesite (REECO3F) and hydroxylbastnaesite (REECO3OH) include beam sensitivity, quantification of light elements in a heavy element matrix, the presence of elements that cannot be analyzed with EPMA (H), and the use of x-ray lines whose physical constants are not well known. To overcome some of these challenges, Ca, La, Ce, Pr, Nd, and Sm were analyzed at 15 keV acce
AuthorsHeather A. LowersPyritization history in the middle to upper Cambrian Alum Shale, Scania Sweden: Evidence for ongoing diagenetic processes
Detailed diagenetic studies of the late Cambrian Alum Shale in southern Sweden were undertaken across an interval that includes the peak Steptoean Positive Carbon Isotope Excursion (SPICE) event to evaluate the pyrite mineralization history in the formation. Samples were collected from the Andrarum-3 core (Scania, Sweden); here the Alum was deposited in the distal, siliciclastic mudstone-rich endAuthorsNeil S. Fishman, Sven O. Egenhoff, Heather A. Lowers, Adam Boehlke, Per AhlbergThe 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 type of dolomite and three different generations oAuthorsSven Egenhoff, Neil Fishman, Heather A. Lowers, Per AhlbergAbsence 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 contents as determined by EMP and LA-ICP-MS due to ruAuthorsCorey J. Meighan, Albert H. Hofstra, David Adams, Erin E. Marsh, Heather A. Lowers, Alan KoenigGeochemistry 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 of mafic to intermediate intrusions whereas hematiAuthorsCorey J. Meighan, Albert H. Hofstra, Erin E. Marsh, Heather A. Lowers, Alan KoenigMethod 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 particles in biopsied lung tissue from three human groups using fielAuthorsHeather A. Lowers, George N. Breit, Matthew Strand, Renee M. Pillers, Gregory P. Meeker, Todor I. Todorov, Geoffrey S. Plumlee, Ruth E. Wolf, Maura Robinson, Jane Parr, Robert J. Miller, Steve Groshong, Francis Green, Cecile RoseCharacterizing 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 time-consuming analyses at an off-site laboratory.AuthorsGregg A. Swayze, Heather A. Lowers, William Benzel, Roger N. Clark, Rhonda L. Driscoll, Zac S. Perlman, Todd M. Hoefen, M. Darby DyarGeochemistry 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 resource of critical HREEs. Petrographically, the primaAuthorsCliff D. Taylor, Heather A. Lowers, David Adams, R. James Robinson - News