Nature and origin of C-rich ordinary chondrites and chondritic clastsThe abundance and the isotopic compositions of C, O, and noble gases were investigated together with the petrologic characteristics of four carbon-rich ordinary chondrites (Sharps and Allan Hills A77011, A78119, and A81024) and three C-rich chondritic clasts. The results of the analyses suggest that all of the chondrites and clasts analyzed belong to petrologic type 3 and contain abundant carbon-rich aggregates, which, in at least two of these samples, consist of poorly graphitized carbon commonly associated with metallic Fe,Ni. The data also suggest that the four C-rich chondrites originated on the H, L, and LL parental bodies, but that clasts in Dimmitt and Plainview and other regolith breccias may come from different bodies. The results obtained are consistent with the view that graphite is not a common nebular phase.
Document ID
19890023521
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Scott, E. R. D. (New Mexico Univ. Albuquerque, NM, United States)
Brearley, A. J. (New Mexico Univ. Albuquerque, NM, United States)
Keil, K. (New Mexico, University Albuquerque, United States)
Grady, M. M. (New Mexico Univ. Albuquerque, NM, United States)
Pillinger, C. T. (Open University Milton Keynes, United Kingdom)