Gregg A Swayze, Ph.D.
Gregg Swayze is a Scientist Emeritus in Denver. Gregg received a Doctorate in Geology from the University of Colorado in 1997. Since joining the USGS in 1985, Gregg has devoted his career to studying Remote Sensing and specializes in Imaging Spectroscopy. Presently, his science focuses on environmental and mineral exploration applications of imaging spectroscopy.
Research Interests
Over the years, Gregg has developed methods to spectrally map acid-mine drainage in Leadville, Colorado, naturally-occurring asbestos in the foothills of California, insulation asbestos in the World Trade Center dust, and oil emulsions formed during the 2010 BP oil spill. He has also developed a portable spectral fingerprinting technique to identify asbestos-bearing vermiculite in attic insulation. Gregg has used his imaging spectroscopy experience with relict hydrothermal systems in Nevada and Hawaii to help map similar mineral deposits on the surface of Mars with the NASA CRISM orbital spectrometer. His most recent focus is on spectrally mapping REE-bearing minerals at the Mt. Pass Mine in California. He was recently selected as a Co-Investigator of the NASA/JPL Earth Surface Mineral Dust Source Investigation (EMIT) team with the goal of putting an imaging spectrometer on the International Space Station to map the mineralogy of dust source regions on a global basis.
Professional Experience
1985 to present, U.S. Geological Survey, Denver, Colorado
Education and Certifications
Ph.D. degree/Geology, University of Colorado, 1997
M.S. degree/Geology, Colorado School of Mines, 1985
B.S. degree/Geology, Grand Valley State University, 1982
Affiliations and Memberships*
American Geophysical Union
Geological Society of America
Colorado Scientific Society
Society of Economic Geologists
Science and Products
A synthesis of Martian aqueous mineralogy after 1 Mars year of observations from the Mars Reconnaissance Orbiter
Identification of hydrated silicate minerals on Mars using MRO-CRISM: Geologic context near Nili Fossae and implications for aqueous alteration
Discovery of jarosite within the Mawrth Vallis region of Mars: Implications for the geologic history of the region
Mapping potentialy asbestos-bearing rocks using imaging spectroscopy
Opaline silica in young deposits on Mars
Phyllosilicate and sulfate-hematite deposits within Miyamoto crater in Southern Sinus Meridiani, Mars
Phyllosilicate diversity and past aqueous activity revealed at Mawrth Vallis, Mars
Hydrated silicate minerals on Mars observed by the Mars Reconnaissance Orbiter CRISM instrument
Orbital identification of carbonate-bearing rocks on Mars
USGS Digital Spectral Library splib06a
Mineralogy and Morphology of Amphiboles Observed in Soils and Rocks in El Dorado Hills, California
Spectroscopic and x-ray diffraction analyses of asbestos in the World Trade Center dust: Asbestos content of the settled dust
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Filter Total Items: 71
A synthesis of Martian aqueous mineralogy after 1 Mars year of observations from the Mars Reconnaissance Orbiter
Martian aqueous mineral deposits have been examined and characterized using data acquired during Mars Reconnaissance Orbiter's (MRO) primary science phase, including Compact Reconnaissance Imaging Spectrometer for Mars hyperspectral images covering the 0.4-3.9 ??m wavelength range, coordinated with higher-spatial resolution HiRISE and Context Imager images. MRO's new high-resolution measurements,AuthorsS.L. Murchie, J.F. Mustard, B.L. Ehlmann, R.E. Milliken, J.L. Bishop, N.K. McKeown, E.Z. Noe Dobrea, F.P. Seelos, D.L. Buczkowski, S.M. Wiseman, R. E. Arvidson, J.J. Wray, G. Swayze, R. N. Clark, D.J. Des Marais, A. S. McEwen, J.-P. BibringIdentification of hydrated silicate minerals on Mars using MRO-CRISM: Geologic context near Nili Fossae and implications for aqueous alteration
[1] The Noachian terrain west of the Isidis basin hosts a diverse collection of alteration minerals in rocks comprising varied geomorphic units within a 100,000 km2 region in and near the Nili Fossae. Prior investigations in this region by the Observatoire pour l'Minéralogie, l'Eau, les Glaces, et l'Activité (OMEGA) instrument on Mars Express revealed large exposures of both mafic minerals and iroAuthorsB.L. Ehlmann, J.F. Mustard, G.A. Swayze, R. N. Clark, J.L. Bishop, F. Poulet, D.J. Des Marais, L.H. Roach, R.E. Milliken, J.J. Wray, O. Barnouin-Jha, S.L. MurchieDiscovery of jarosite within the Mawrth Vallis region of Mars: Implications for the geologic history of the region
Analysis of visible to near infrared reflectance data from the MRO CRISM hyperspectral imager has revealed the presence of an ovoid-shaped landform, approximately 3 by 5 km in size, within the layered terrains surrounding the Mawrth Vallis outflow channel. This feature has spectral absorption features consistent with the presence of the ferric sulfate mineral jarosite, specifically a K-bearing jarAuthorsW. H. Farrand, T.D. Glotch, J. W. Rice, J.A. Hurowitz, G.A. SwayzeMapping potentialy asbestos-bearing rocks using imaging spectroscopy
Rock and soil that may contain naturally occurring asbestos (NOA), a known human carcinogen, were mapped in the Sierra Nevada, California, using the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) to determine if these materials could be uniquely identified with spectroscopy. Such information can be used to prepare or refine maps of areas that may contain minerals that can be asbestiform,AuthorsG.A. Swayze, R.F. Kokaly, C.T. Higgins, J.P. Clinkenbeard, R. N. Clark, H.A. Lowers, S. J. SutleyOpaline silica in young deposits on Mars
High spatial and spectral resolution reflectance data acquired by the Mars Reconnaissance Orbiter Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) instrument reveal the presence of H2O- and SiOH-bearing phases on the Martian surface. The spectra are most consistent with opaline silica and glass altered to various degrees, confirming predictions based on geochemical experiments and modeAuthorsRalph E. Milliken, Gregg A. Swayze, Raymond E. Arvidson, Janice L Bishop, Roger N. Clark, Bethany L. Ehlmann, Robert O. Green, John P. Grotzinger, R.V. Morris, Scott L. Murchie, John F. Mustard, C. WeitzPhyllosilicate and sulfate-hematite deposits within Miyamoto crater in Southern Sinus Meridiani, Mars
Orbital topographic, image, and spectral data show that sulfate- and hematite-bearing plains deposits similar to those explored by the MER rover Opportunity unconformably overlie the northeastern portion of the 160 km in diameter Miyamoto crater. Crater floor materials exhumed to the west of the contact exhibit CRISM and OMEGA NIR spectral signatures consistent with the presence of Fe/Mg-rich smecAuthorsS.M. Wiseman, R. E. Arvidson, J. C. Andrews-Hanna, R. N. Clark, N.L. Lanza, D. des Marais, G.A. Marzo, R.V. Morris, S.L. Murchie, Horton E. Newsom, E.Z. Noe Dobrea, A.M. Ollila, F. Poulet, T. L. Roush, F.P. Seelos, G.A. SwayzePhyllosilicate diversity and past aqueous activity revealed at Mawrth Vallis, Mars
Observations by the Mars Reconnaissance Orbiter/Compact Reconnaissance Imaging Spectrometer for Mars in the Mawrth Vallis region show several phyllosilicate species, indicating a wide range of past aqueous activity. Iron/magnesium (Fe/Mg)-smectite is observed in light-toned outcrops that probably formed via aqueous alteration of basalt of the ancient cratered terrain. This unit is overlain by rockAuthorsJ.L. Bishop, E.Z.N. Dobrea, N.K. McKeown, M. Parente, B.L. Ehlmann, J.R. Michalski, R.E. Milliken, F. Poulet, G.A. Swayze, J.F. Mustard, S.L. Murchie, J.-P. BibringHydrated silicate minerals on Mars observed by the Mars Reconnaissance Orbiter CRISM instrument
Phyllosilicates, a class of hydrous mineral first definitively identified on Mars by the OMEGA (Observatoire pour la Mineralogie, L’Eau, les Glaces et l’Activitié) instrument1,2, preserve a record of the interaction of water with rocks on Mars. Global mapping showed that phyllosilicates are widespread but are apparently restricted to ancient terrains and a relatively narrow range of mineralogy (FeAuthorsJ.F. Mustard, S.L. Murchie, S.M. Pelkey, B.L. Ehlmann, R.E. Milliken, J. A. Grant, J.-P. Bibring, F. Poulet, J. Bishop, E. N. Dobrea, L. Roach, F. Seelos, R. E. Arvidson, S. Wiseman, R. Green, C. Hash, D. Humm, E. Malaret, J.A. McGovern, K. Seelos, T. Clancy, R. Clark, D. des Marais, N. Izenberg, A. Knudson, Y. Langevin, T. Martin, P. McGuire, Robert Morris, M. Robinson, T. Roush, M. Smith, G. Swayze, H. Taylor, T. Titus, M. WolffOrbital identification of carbonate-bearing rocks on Mars
Geochemical models for Mars predict carbonate formation during aqueous alteration. Carbonate-bearing rocks had not previously been detected on Mars' surface, but Mars Reconnaissance Orbiter mapping reveals a regional rock layer with near-infrared spectral characteristics that are consistent with the presence of magnesium carbonate in the Nili Fossae region. The carbonate is closely associated withAuthorsB.L. Ehlmann, J.F. Mustard, S.L. Murchie, F. Poulet, J.L. Bishop, A.J. Brown, W. M. Calvin, R. N. Clark, D.J. Des Marais, R.E. Milliken, L.H. Roach, T. L. Roush, G.A. Swayze, J.J. WrayUSGS Digital Spectral Library splib06a
Introduction We have assembled a digital reflectance spectral library that covers the wavelength range from the ultraviolet to far infrared along with sample documentation. The library includes samples of minerals, rocks, soils, physically constructed as well as mathematically computed mixtures, plants, vegetation communities, microorganisms, and man-made materials. The samples and spectra collAuthorsRoger N. Clark, Gregg A. Swayze, Richard A. Wise, K. Eric Livo, Todd M. Hoefen, Raymond F. Kokaly, Stephen J. SutleyMineralogy and Morphology of Amphiboles Observed in Soils and Rocks in El Dorado Hills, California
From the Executive Summary: At the request of the U.S. Environmental Protection Agency (USEPA), the U.S. Geological Survey (USGS) has conducted an independent study of amphiboles in rocks and soils in the El Dorado Hills, California, area. The purpose of this study is to investigate specific issues regarding the presence of 'naturally occurring asbestos' raised by an USEPA activity-based samplingAuthorsG.P. Meeker, H.A. Lowers, G.A. Swayze, B. S. Van Gosen, S. J. Sutley, I. K. BrownfieldSpectroscopic and x-ray diffraction analyses of asbestos in the World Trade Center dust: Asbestos content of the settled dust
On September 17 and 18, 2001, samples of settled dust and airfall debris were collected from 34 sites within a 1-km radius of the WTC collapse site, including a sample from an indoor location unaffected by rainfall, and samples of insulation from two steel beams at Ground Zero. Laboratory spectral and x-ray diffraction analyses of the field samples detected trace levels of serpentine minerals, incAuthorsGregg A. Swayze, Roger N. Clark, Stephen J. Sutley, Todd M. Hoefen, Geoffrey S. Plumlee, Gregory P. Meeker, Isabelle Brownfield, Keith E. Livo, Laurie C. Morath - Web Tools
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*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government