RESEARCH INTERESTS

I am a mineralogist/petrologist with strong interests in both terrestrial and planetary problems. My research emphasizes the application of microbeam techniques (EPMA, SEM, TEM, SIMS and SXRF) to a wide range of problems in earth and planetary sciences.

I am currently actively involved in a number of terrrestrial and extraterrestrial research projects. For more details follow the links below.

Planetary Science Research    Terrestrial Research    

My terrestrial research interests are centered around understanding the mechanisms and kinetics of high pressure phase transformations in the mantle and their implications for mantle rheology, dynamics and deep focus earthquakes, as well as the mineralogy and petrology of mantle xenoliths. However, I also work on a variety of problems in metamorphic petrology, including mechanisms of metamorphic reactions under disequilibrium conditions, experimental studies of partial melting reactions involving micas in upper crustal rocks and the metamorphic petrology of contact and low grade metamorphic rocks.

Current planetary science and early solar system research projects:

Planetary science and early solar system research

Formation and alteration histories of chondritic meteorites (NASA Cosmochemistry Program).

This project is a multifaceted project that consists of many subproject. Some of these are listed below.

• Studies of aqueous alteration processes in primitive carbonaceous chondrites (NASA)
• Mineralogy and chemistry of fine-grained matrices and rims in chondritic meteorites (NASA).
• Nature and origin of fine-grained matrix materials in primitive chondrites (NASA).
• Effects of metamorphism on the chemistry and microstructural characteristics of carbonaceous chondrite matrices (NASA).
• Origin of carbonates in CM carbonaceous chondrites (NASA). Images of altered CM chondrites
• Origin of carbonates and associated minerals in Martian orthopyroxenite ALH 84001 (NASA).
• Origin of dark inclusions in CV carbonaceous chondrites (NASA).
• Thermal histories of chondrules and chondrites based on the microstructures of pyroxenes (NASA).
• High resolution TEM image of disordered biopyriboles replacing enstatite in a chondrule from the Allende meteorite

Mechanisms and kinetics of aqueous alteration reactions in chondritic meteorites (NASA Origins of Solar Systems Program)

• The reaction of liquid or gaseous water with the components of chondritic meteorites was an important and widespread process in the early solar system. It clearly contributed considerably to the evolution of important primitive solar system materials such as carbonaceous chondrites and interplanetary dust particles. With graduate student Paul Burger and Postdoctoral Researcher Barbara Cohen, we are studying carrying out experimental investigations of the kinetics and mechanisms of alteration reactions that affected a variety of chondritic materials. This research aims to place constraints on the possible timing, locations, conditions and nature of these aqueous alteration processes, using experimental methods.

Nature, origins and thermal processing of carbonaceous material in chondritic meteorites: In situ location using energy filtered transmission electron microscopy (NASA Exobiology Program).

Terrestrial research projects