Research Topics

Application of chemical thermodynamics, kinetics and surface chemistry to the characterization of mineral-solution interactions in aquatic environments, carbonate geochemistry, early diagenesis of marine and coastal sediments, trace metal and environmental geochemistry in freshwater and marine systems.

Investigation of process occurring at the interface between inorganic and organic phases leading to the nucleation and growth of crystals in both natural and synthetic systems. Pathogenic mineralization and calcification in mammalian cells and tissues. Investigating biomarkers as signatures of ancient biological activity in terrestrial and extraterrestrial materials.

Studies of the genesis of hydrothermal mineral deposits through a combination of field-based, experimental and theoretical methods. Research focuses on the understanding of physico-chemical controls of mineralization, through geological mapping of deposits, experimental studies of metal solubility and speciation in hydrothermal systems, simulations of hydrothermal alteration and theoretical studies designed to estimate conditions of alteration and ore formation.

Studies of pore-water flow in northern peatlands, heat transport, heat as a tracer of natural systems, groundwater modeling, coupled numerical models of pore water flow and heat transport with freeze/thaw processes, and the impact of melting tropical glaciers on water resources.

Experimental studies of the structure, thermodynamics, and transport properties (diffusion and viscosity) of silicate melts and applications to igneous petrogenesis. The nature of the Earth's upper mantle and the processes within it which give rise to basaltic volcanism on both the Earth and the other terrestrial planets. Applications of laser ablation ICPMS; Petrology, geochemistry, and tectonics of the Appalachian lithosphere.

Chemistry and crystallography of carbonate minerals. Experimental investigations of the effect of environmental factors (e.g., solution composition and temperature) on the morphology and composition of calcite.

Links between the marine ecosystem and climate through observations of the modern ocean, simulations of ocean biogeochemistry with computer models, and sedimentary records of past climate change.

Sedimentology, stratigraphy, and isotope geochemistry as guides to reconstructing ancient environments. Reconstruction of paleoenvironmental change during the Neoproterozoic to early Phanerozoic. Relationships between between tectonics (i.e. supercontinental break-up and assembly), seawater chemistry and ocean redox, severe climatic fluctuations (including snowball Earth), and the origin and diversification of animals. Recovery of the geochemical memory of large-scale Earth system processes (e.g., microbial control of the global S cycle; anthropogenic manipulation of atmospheric OH abundances). Investigations of microbial biogeochemistry under an anoxic Archean atmosphere, to constrain mass fluxes in the Phanerozoic geologic sulfur cycle, and to track processes that control the pollution-cleansing oxidants (OH, O3) in the modern atmosphere.

The interactions of climate and tectonics, especially in regard to the formation and degradation of orogens. Understanding the paleoclimatic and neotectonic history of Plio-Pleistocene landscape development using cosmogenic-dating techniques. Archean orogenic processes.

Petrology and geochemistry of intermediate and felsic magmas. Understanding physical processes and forecasting eruptions at active subduction-zone volcanoes. Geochemistry of volcanic gases, their use for eruption prediction, and their impact on the atmosphere.