A5079711008- Geochemistry and Elemental Analysis
- Radioactive element chemistry and processing
- Mine drainage and remediation techniques
- Heavy metals in environment
- Geological and Geochemical Analysis
- Extraction and Separation Processes
- Geochemistry and Geologic Mapping
- Iron oxide chemistry and applications
- Analytical chemistry methods development
- Groundwater and Isotope Geochemistry
- Mercury impact and mitigation studies
- Mining Techniques and Economics
- Planetary Science and Exploration
- Astro and Planetary Science
- Geotechnical and Geomechanical Engineering
- Space Exploration and Technology
- Aquatic and Environmental Studies
- Water Quality Monitoring and Analysis
- Water Quality and Pollution Assessment
- Arsenic contamination and mitigation
- Selenium in Biological Systems
- Geological Modeling and Analysis
- Bauxite Residue and Utilization
- Geology and Paleoclimatology Research
- Hydrocarbon exploration and reservoir analysis
Washington and Lee University
2020-2025
Smithsonian Institution
2022
Washington University in St. Louis
2015-2017
Mars Reconnaissance Orbiter HiRISE images and Opportunity rover observations of the ~22 km wide Noachian age Endeavour Crater on show that rim surrounding terrains were densely fractured during impact crater-forming event. Fractures have also propagated upward into overlying Burns formation sandstones. Opportunity's western crater segment, called Murray Ridge, is composed breccias with basaltic compositions, as well occasional fracture-filling calcium sulfate veins. Cook Haven, a gentle...
Layered Mn oxide minerals (phyllomanganates) often control trace metal fate in natural systems. The strong uptake of metals such as Ni and Zn by phyllomanganates results from adsorption on or incorporation into vacancy sites. Mn(II) also binds to vacancies subsequent comproportionation with structural Mn(IV) may alter sheet structures forming larger distorted Mn(III)O6 octahedra. Such Mn(II)-phyllomanganate reactions thus blocking key reactive Here we investigate the effect binding varying...
Selenium (Se) redox chemistry is a determining factor for its environmental toxicity and mobility. Currently, millions of people are impacted by Se deficiency or toxicity, in geologic history, several mass extinctions have been linked to extreme deficiency. Importantly, microbial activity interactions with other biogeochemically active elements can drastically alter oxidation state form, impacting bioavailability. Here, we use wet geochemistry, spectroscopy, electron microscopy identify...
Manganese oxides influence Ni partitioning in natural and metal-polluted systems through adsorption incorporation. Understanding behavior within environmental contexts requires knowledge of its binding to environmentally relevant minerals such as birnessite during after precipitation. Here, we compare at initial (48-h) aged (14-day) time frames onto fungal (via Stagonospora sp. SRC1lsM3a) abiotic birnessite, fungi are important Mn oxidizers contaminated sites, with two timing-of-addition...
Abstract Manganese (Mn) is of particular concern in groundwater, as low-level chronic exposure to aqueous Mn concentrations drinking water can result a variety health and neurodevelopmental effects. Much the global population relies on sourced from karst aquifers. Thus, we seek assess relative risk contamination by investigating Shenandoah Valley, VA region, it underlain both non-karst aquifers much wells spring water. Water soil samples were collected throughout supplement pre-existing well...
A method for determining nanogram quantities of mercury in geological materials is based on the catalytic effect reaction ferrocyanide with nitrosobenzene to produce a violet-covered compound whose intensity if proportional present. The released by heating sample soil or crushed rock about 650°C. As little as 30 nanograms (30 parts per billion 1 gram sample) can be detected. reliability adequate permit its use geochemical surveys that utilize pathfinder element.
A large titanium anomaly (anomaly A) was identified in Harrison, Taylor, and Doddridge Counties, West Virginia from a geochemical evaluation of statewide NURE stream sediment data.The is underlain by the Upper Pennsylvanian Monongahela Group, encompasses contact with overlying Dunkard Group coal measures.The is: (1) associated cerium-group rare earth elements (REE), Ba, Sr, Au, Sn, Cu, Pb, Mn, Al, Th, Fe, V; (2) elliptical plan on basis contour plot, crosscuts regional stratigraphic trends;...
The Mineral Hot Springs and Valley View Known Geothermal Resurce Areas are located in the northern part of San Luis Valley, Colo-ado.To seek evidence for possible extensions these hot spring systems, U.S. Geological Survey conducted surveys utilizing surficial geochendcal biogeochendcal exploration techniques.The objective study was to see if analyses soil samples, gases, rabbitbrush (genus Chrysathamnus) could detect springs.Many anomalies were observed be associated with large fault...