A5008721009- Geological and Geochemical Analysis
- Planetary Science and Exploration
- Geochemistry and Geologic Mapping
- Geology and Paleoclimatology Research
- Paleontology and Stratigraphy of Fossils
- High-pressure geophysics and materials
- Astro and Planetary Science
- earthquake and tectonic studies
- Geochemistry and Elemental Analysis
- Isotope Analysis in Ecology
- Clay minerals and soil interactions
- Mineralogy and Gemology Studies
- Geomagnetism and Paleomagnetism Studies
- Geological and Geophysical Studies
- Space Science and Extraterrestrial Life
- Evolution and Paleontology Studies
- Space Exploration and Technology
- Geological Studies and Exploration
- Pleistocene-Era Hominins and Archaeology
- Methane Hydrates and Related Phenomena
- Iron oxide chemistry and applications
- Building materials and conservation
- Crystal Structures and Properties
- Laser-induced spectroscopy and plasma
- Geological Modeling and Analysis
Franklin & Marshall College
2014-2024
Case Western Reserve University
1978-1979
Smithsonian Institution
1974
Major element, multispectral, and magnetic properties data were obtained at Ares Vallis during the Mars Pathfinder mission. To understand compositional, mineralogical, process implications of these data, we major for well‐crystalline nanophase ferric minerals, terrestrial analogue samples with known geologic context, SNC meteorites. Analogue include unaltered, palagonitic, sulfatetic tephra from Mauna Kea Volcano (hydrolytic acid‐sulfate alteration), steam vent material Kilauea impactites...
Middle to late Cenozoic mafic lavas from the Ethiopian volcanic province exhibit considerable chemical and isotopic diversity that is linked eruption age location. These variations provide a geochemical framework in which continental rifting can be examined. Trace element Sr, Nd, Pb data are interpreted indicate involvement of up two depleted enriched mantle reservoirs throughout rift development Ethiopia. Superimposed on characteristics imparted by varying degrees melting these distinct...
Research Article| February 01, 1984 Areal distribution and age of low-K, high-alumina olivine tholeiite magmatism in the northwestern Great Basin WILLIAM K. HART; HART 1Department Geological Sciences, Case Western Reserve University, Cleveland, Ohio 44106 Search for other works by this author on: GSW Google Scholar JAMES L. ARONSON; ARONSON STANLEY A. MERTZMAN 2Department Geology, Franklin Marshall College, Lancaster, Pennsylvania 17604 Author Article Information Publisher: Society America...
The mineralogical and elemental composition of dust size fractions (<2 <5 μm) eight samples phyllosilicate‐poor palagonitic tephra from the upper slopes Mauna Kea Volcano (Hawaii) were studied by X‐ray diffraction (XRD), fluorescence (XRF), visible near‐IR reflectance spectroscopy, Mössbauer magnetic properties methods, transmission electron microscopy (TEM). are spectral analogues Martian bright regions at wavelengths. crystalline phases in are, variable proportions, plagioclase...
We studied visible to near‐infrared (VNIR, 0.35–2.5 μ m) and middle infrared (MIR, 1800–250 cm −1 , also called thermal vibrational) spectra of basaltic tephras from Mauna Kea volcano that were altered under ambient, hydrothermal (hydrolytic acid sulfate), dry heat conditions. Although models MIR generally produce fits whose quality is reduced compared deconvolutions primary lithologies, they successfully identify major alteration phases (cristobalite, oxide, phyllosilicate, sulfate) except...
Midinfrared (∼1600–200 cm −1 ) spectral data received from the Mars Global Surveyor Thermal Emission Spectrometer (MGS TES) have provided evidence for a large hematite‐bearing (α‐Fe 2 O 3 deposit in Sinus Meridiani, Mars. We report here results of laboratory spectroscopic investigation 24 hematite samples, including polycrystalline hand samples (massive and schistose textures), single‐crystal particle‐size fractions (single‐crystal discrete particles). Laboratory midinfrared analyses...
Acid‐sulfate weathering of basaltic materials is a candidate formation process for the sulfate‐rich outcrops and rocks at MER rover Opportunity Spirit landing sites. To determine style acid‐sulfate on Mars, we weathered (olivine‐rich glassy sand plagioclase feldspar‐rich tephra) in laboratory under different oxidative, conditions characterized alteration products. We investigated by (1) sulfuric‐acid vapor (acid fog), (2) three‐step hydrothermal leaching treatment approximating an “open...