A New Approach to Characterizing Evidence of Parent Body Alteration in Carbonaceous Chondrite Meteorites
Primitive meteorites contain a record of processes that are key to understanding the formation and early history of our Solar System. They are remnants of the materials that formed the planets and as such, knowledge of their number, physical properties, compositions, and the spatial distribution of these characteristics at all scales provides important constraints on models of planetary formation. Although they lack direct geologic context, the chemistry and mineralogy of meteorites provide us with a detailed understanding of the range of compositions represented by their parent bodies, as well as the thermal and aqueous conditions to which their constituents were exposed at various locations and times. For example, abundant mineralogical evidence for the aqueous alteration of chondritic materials early in solar system history is present across nearly all major chondrite groups in the form of hydrated or other secondary phases. I will discuss how a new approach to measuring meteorite mineralogy and hydration, spatially resolved infrared microspectroscopy, can be used to examine the speciation and distribution of water in carbonaceous chondrites. Ultimately, a better understanding of the nature and distribution of alteration products may provide additional constraints to help distinguish between models of aqueous alteration in cases where other evidence is ambiguous.