Heather A Lowers
Heather Lowers is a Research Geologist with the Geology, Geophysics, and Geochemistry Science Center.
Science and Products
Filter Total Items: 31
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 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
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...
Tables of electron probe microanalyses from the Copperwood sediment-hosted stratiform copper deposit, Michigan, USA 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 between 98.5 and 101.5...
Data Dictionary for Electron Microprobe Data Collected with Probe for EPMA Software Package Developed by Probe Software 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 depend...
Lung Bioassay of Ground Dwelling Mammals from the Grand Canyon Uranium Breccia Pipe Region Using Scanning Electron Microscopy 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...
In situ geochemical data related to the gold-quartz veins of Grass Valley, California, 2014-2015 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 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...
Particulate Matter Identification in Lung Tissue from Deployers, Positive, and Negative controls Using Scanning Electron Microscopy and Energy Dispersive Spectroscopy (2013-2016) 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 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...
USGS Spectral Library Version 7 Data 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 man-made...
Filter Total Items: 106
Formation of orogenic gold deposits by progressive movement of a fault-fracture mesh through the upper crustal brittle-ductile transition zone Formation of orogenic gold deposits by progressive movement of a fault-fracture mesh through the upper crustal brittle-ductile transition zone
Orogenic gold deposits are comprised of complex quartz vein arrays that form as a result of fluid flow along transcrustal fault zones in active orogenic belts. Mineral precipitation in these deposits occurs under variable pressure conditions, but a mechanism explaining how the pressure regimes evolve through time has not previously been proposed. Here we show that extensional quartz...
Authors
Miguel Tavares Nassif, Thomas Monecke, T. James Reynolds, Yvette D. Kuiper, Richard J. Goldfarb, Sandra Piazolo, Heather A. Lowers
Quantitative and qualitative correlation of CL and X-ray signals in Cr-bearing jade from Chichén-Itzá Archaeological Zone, Mexico Quantitative and qualitative correlation of CL and X-ray signals in Cr-bearing jade from Chichén-Itzá Archaeological Zone, Mexico
No abstract available.
Authors
E Vicenzi, Thomas Lam, Heather A. Lowers, Paul K. Carpenter, David T. Adams
Cathodoluminescence response of barite at room and liquid nitrogen temperatures Cathodoluminescence response of barite at room and liquid nitrogen temperatures
Rare earth element (REE) enrichment in the Elk Creek carbonatite, Nebraska USA, is comparable to ore grade enrichment in carbonatite-hosted REE deposits[1]. Petrographic examination of textures documents a complex history of crystallization, brecciation, recrystallization, oxidation, and near surface alteration. Barite (BaSO4) is present in most units, including REE-enriched zones, such...
Authors
Heather A. Lowers, Colin MacRae, Nick Wilson, Philip Verplanck
The geochemical and textural transition between the Reef Package and its hanging wall, Stillwater Complex, Montana, USA The geochemical and textural transition between the Reef Package and its hanging wall, Stillwater Complex, Montana, USA
The highest grade Pd-Pt deposit on Earth, the J-M Reef, is hosted in coarse-grained to pegmatoidal cumulates called the Reef Package. Decades of mine development of the J-M Reef have revealed that a distinct discontinuity in rock fabric marks the top of the rock unit that hosts economic-grade sulfide mineralization. Mine geologists refer to this discontinuity as the hanging wall contact...
Authors
M. Christopher Jenkins, James E. Mungall, Michael L. Zientek, Kevin Butak, Sam R. Corson, Paul Holick, Ryan McKinley, Heather A. Lowers
Demonstration of a novel quantitative microscopy technique for automated characterization of in situ particulate matter in coal miners with progressive massive fibrosis 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...
Authors
Jeremy 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. Rose
The dynamic floor of Yellowstone Lake, Wyoming, USA: The last 14 k.y. of hydrothermal explosions, venting, doming, and faulting The 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...
Authors
Lisa 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. Licciardi
Petrogenesis and rare earth element mineralization of the Elk Creek carbonatite, Nebraska, USA Petrogenesis 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...
Authors
Philip Verplanck, G. Lang Farmer, Richard M. Kettler, Heather A. Lowers, Craig A. Johnson, Alan E. Koenig, Michael J. Blessington
Pathology and mineralogy demonstrate respirable crystalline silica is a major cause of severe pneumoconiosis in US coal miners Pathology 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...
Authors
R. 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. Green
Approach for quantifying rare Earth elements at low keV 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...
Authors
Heather A. Lowers
Pyritization history in the middle to upper Cambrian Alum Shale, Scania Sweden: Evidence for ongoing diagenetic processes Pyritization 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...
Authors
Neil S. Fishman, Sven O. Egenhoff, Heather A. Lowers, Adam Boehlke, Per Ahlberg
The complexity of mudstone diagenesis - some insight from the Tøyen Formation, Lower to Middle Ordovician, southern Sweden 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 type of dolomite and three different...
Authors
Sven Egenhoff, Neil Fishman, Heather A. Lowers, Per Ahlberg
Absence of magnetite microlites, geochemistry of magnetite veins and replacements in IOA deposits, SE Missouri, USA: Relations to intermediate intrusions 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 contents as determined by EMP and LA-ICP-MS...
Authors
Corey J. Meighan, Albert H. Hofstra, David Adams, Erin E. Marsh, Heather A. Lowers, Alan Koenig
Science and Products
Filter Total Items: 31
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 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
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...
Tables of electron probe microanalyses from the Copperwood sediment-hosted stratiform copper deposit, Michigan, USA 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 between 98.5 and 101.5...
Data Dictionary for Electron Microprobe Data Collected with Probe for EPMA Software Package Developed by Probe Software 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 depend...
Lung Bioassay of Ground Dwelling Mammals from the Grand Canyon Uranium Breccia Pipe Region Using Scanning Electron Microscopy 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...
In situ geochemical data related to the gold-quartz veins of Grass Valley, California, 2014-2015 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 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...
Particulate Matter Identification in Lung Tissue from Deployers, Positive, and Negative controls Using Scanning Electron Microscopy and Energy Dispersive Spectroscopy (2013-2016) 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 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...
USGS Spectral Library Version 7 Data 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 man-made...
Filter Total Items: 106
Formation of orogenic gold deposits by progressive movement of a fault-fracture mesh through the upper crustal brittle-ductile transition zone Formation of orogenic gold deposits by progressive movement of a fault-fracture mesh through the upper crustal brittle-ductile transition zone
Orogenic gold deposits are comprised of complex quartz vein arrays that form as a result of fluid flow along transcrustal fault zones in active orogenic belts. Mineral precipitation in these deposits occurs under variable pressure conditions, but a mechanism explaining how the pressure regimes evolve through time has not previously been proposed. Here we show that extensional quartz...
Authors
Miguel Tavares Nassif, Thomas Monecke, T. James Reynolds, Yvette D. Kuiper, Richard J. Goldfarb, Sandra Piazolo, Heather A. Lowers
Quantitative and qualitative correlation of CL and X-ray signals in Cr-bearing jade from Chichén-Itzá Archaeological Zone, Mexico Quantitative and qualitative correlation of CL and X-ray signals in Cr-bearing jade from Chichén-Itzá Archaeological Zone, Mexico
No abstract available.
Authors
E Vicenzi, Thomas Lam, Heather A. Lowers, Paul K. Carpenter, David T. Adams
Cathodoluminescence response of barite at room and liquid nitrogen temperatures Cathodoluminescence response of barite at room and liquid nitrogen temperatures
Rare earth element (REE) enrichment in the Elk Creek carbonatite, Nebraska USA, is comparable to ore grade enrichment in carbonatite-hosted REE deposits[1]. Petrographic examination of textures documents a complex history of crystallization, brecciation, recrystallization, oxidation, and near surface alteration. Barite (BaSO4) is present in most units, including REE-enriched zones, such...
Authors
Heather A. Lowers, Colin MacRae, Nick Wilson, Philip Verplanck
The geochemical and textural transition between the Reef Package and its hanging wall, Stillwater Complex, Montana, USA The geochemical and textural transition between the Reef Package and its hanging wall, Stillwater Complex, Montana, USA
The highest grade Pd-Pt deposit on Earth, the J-M Reef, is hosted in coarse-grained to pegmatoidal cumulates called the Reef Package. Decades of mine development of the J-M Reef have revealed that a distinct discontinuity in rock fabric marks the top of the rock unit that hosts economic-grade sulfide mineralization. Mine geologists refer to this discontinuity as the hanging wall contact...
Authors
M. Christopher Jenkins, James E. Mungall, Michael L. Zientek, Kevin Butak, Sam R. Corson, Paul Holick, Ryan McKinley, Heather A. Lowers
Demonstration of a novel quantitative microscopy technique for automated characterization of in situ particulate matter in coal miners with progressive massive fibrosis 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...
Authors
Jeremy 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. Rose
The dynamic floor of Yellowstone Lake, Wyoming, USA: The last 14 k.y. of hydrothermal explosions, venting, doming, and faulting The 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...
Authors
Lisa 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. Licciardi
Petrogenesis and rare earth element mineralization of the Elk Creek carbonatite, Nebraska, USA Petrogenesis 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...
Authors
Philip Verplanck, G. Lang Farmer, Richard M. Kettler, Heather A. Lowers, Craig A. Johnson, Alan E. Koenig, Michael J. Blessington
Pathology and mineralogy demonstrate respirable crystalline silica is a major cause of severe pneumoconiosis in US coal miners Pathology 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...
Authors
R. 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. Green
Approach for quantifying rare Earth elements at low keV 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...
Authors
Heather A. Lowers
Pyritization history in the middle to upper Cambrian Alum Shale, Scania Sweden: Evidence for ongoing diagenetic processes Pyritization 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...
Authors
Neil S. Fishman, Sven O. Egenhoff, Heather A. Lowers, Adam Boehlke, Per Ahlberg
The complexity of mudstone diagenesis - some insight from the Tøyen Formation, Lower to Middle Ordovician, southern Sweden 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 type of dolomite and three different...
Authors
Sven Egenhoff, Neil Fishman, Heather A. Lowers, Per Ahlberg
Absence of magnetite microlites, geochemistry of magnetite veins and replacements in IOA deposits, SE Missouri, USA: Relations to intermediate intrusions 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 contents as determined by EMP and LA-ICP-MS...
Authors
Corey J. Meighan, Albert H. Hofstra, David Adams, Erin E. Marsh, Heather A. Lowers, Alan Koenig