ACFER-094, A UNIQUELY PRIMITIVE CARBONACEOUS CHONDRITE FROM THE SAHARA

The Saharan meteorite Acfer 094 is a unique type of carbonaceous chond rite. Mineralogical and petrological considerations and O isotopes are unable to distinguish unambiguously between a CO3 vs. CM2 classificat ion. The other important light elements, C and N, have systematics tha t do not match any previously recognised meteorite group. Particularly important in this respect is the very low C/N ratio and delta C-13 of the macromolecular C. Acfer 094 has more diamond and SiC, especially X type grains, than any other specimen studied, suggesting minimal the rmal or aqueous processing to decrease its very primitive status.