Lawrence Grossman Professor, Department of the Geophysical Sciences, Enrico Fermi Institute and the College Department of the Geophysical Sciences 5734 S. Ellis Ave. HGS 385 Chicago, IL 60637 USA Phone: 773/702-8153 E-mail: yosi@midway.uchicago.edu Professor Grossman's Website and Publications Solid Earth and Planetary Sciences

Chemical composition and origin of the solar system

Chondritic meteorites are accumulations of minerals which condensed from the vapor of the solar nebula over a wide temperature range 4.5 billion years ago. Some of these materials underwent mixing and melting and partial evaporation prior to or during their ultimate emplacement into the meteorite parent bodies. There, metamorphism caused the resulting mineral assemblages to approach chemical equilibrium in varying degrees. Since the condensation process was the first chemical fractionation that occurred in the solar system, the unraveling of its history may have important implications for the origin of the chemical differences between the planets and between the various meteorite classes.

In my laboratory, we attempt to determine the physical conditions, chemical and isotopic composition, and degree of heterogeneity of the solar nebula by identifying and studying inclusions of primitive condensates in carbonaceous chondrites. Mineral assemblages and their trace element contents expected to have formed by high-temperature condensation of solids from a solar gas are determined by thermodynamic calculations. Compositions of minerals in meteoritic inclusions are studied by electron microprobe and their textures by optical and scanning electron microscopy. In collaboration with Andrew Davis, the ion microprobe is used to study variations in trace element concentrations and isotopic compositions on a micron scale within individual inclusions. In addition, our efforts to understand these objects have led to numerous off-campus collaborations with laboratories specializing in silicate phase equilibria at very low oxygen fugacity, kinetics of crystallization of silicate melts and kinetics of vaporization of crystalline phases.

Education:

• Ph.D., Yale University, 1972
• F. W. Clarke Medal, Geochemical Society
• J. B. Macelwane Award, American Geophysical Union
• Fellow, Royal Society of Canada