Structure and Bonding of Carbon in Clays from CI Carbonaceous Chondrites

Carbonaceous chondrites (CC) contain a diverse suite of C-rich materials. Acid dissolution of these meteorites leaves a C-rich residue with chemical and structural affinities to kerogen. This material has primarily been analyzed in bulk, and much information has been provided regarding functional groups and elemental and isotopic compositions. However, comparatively little work has been done on C in unprocessed meteorites. Studies of CCs suggest a spatial relationship of some C-rich materials with products of aqueous alteration. Recent studies revealed discrete submicronsized, C-rich particles in Tagish Lake and a range of CM2 meteorites. A challenge is to correlate the findings from the bulk acid-residue studies with those of high-spatial resolution-mineralogical and spectroscopic observations of unprocessed meteorites. Hence, the relationship between the C-rich materials in the acid residues and its form and locations in the unprocessed meteorite remains unclear. Here we provide information on the structure and bonding of C associated with clays in CI carbonaceous chondrites. Additional information is included in the original extended abstract.