(Conel M. O'D. Alexander, Richard W. Carlson, Steven B. Shirey, Fouad Tera, Larry Nittler)

A laboratory program in cosmochemistry addressing the early history of the solar system, the formation and early evolution of meteorites, and the nature of the impact cratering process on Earth A variety of tools in isotope and trace element geochemistry are used, including micromanipulation devices, mass spectrometers, and ion probes. Topics of research include the identification and analysis of interstellar grains in meteorites, the formational mechanisms of chondrules and chrondritic metoerites, the chronology of achondritic asteroidal sources of interplanetary dust particles, and the application of Re-Os isotope systematics to determine the meteoritic component of terrestrial impact crater ejecta and melt rock deposits.

Meteorite picture:A plot of H isotope composition versus water abundance in the melt inclusion glass and the impact melted glasses.The D/H of the magmatic melt inclusion glass is very low compared to the D/H of the impact melted glass.The water in the melt inclusion glass show very little fractionation and its H isotope composition may reflect the initial magmatic H isotope signature of Mars.