Unmixing the SNCs: Chemical, Isotopic, and Petrologic Components of the Martian Meteorites : October 11-12, 2002, Houston, Texas

Abstract

Geochemical and petrologic studies of the Martian meteorites (SNCs) have proliferated in the past few years, from new samples and new analytical methods. A result from these studies is that the chemical and isotopic compositions of the Martian meteorites, all basalts or derived from basaltic magma, can be modeled as mixtures of a limited number of components. These mixing components were the focus of the workshop. How many mixing components can be recognized? Can components defined in one type of system be correlated with components in another system? Do the components represent physical masses of material, or chemical isotopic processes? How and when did the components form, i.e., become separated from the average bulk composition of Mars? How and when did the components come to be mixed into the SNCs? What are the historical, tectonic, and geological implications of the components? A theme was the comparison of Martian geochemistry with those of other planets, especially the Moon. The issues were set against the commonly agreed results that Mars differentiated early, into a core and several silicate materials that could include mantle reservoirs, crust, and/or residua of a magma ocean. Several speakers discussed the idea of an early magma ocean, as many chemical systems in the Martian meteorites are closely analogous to those seen in lunar basalts.