Nanodiamonds and amorphous carbon in carbonaceous-chondrite xenoliths in the Kapoeta meteorite: Astrophysical implications

ABDU Y; HAWTHORNE F.; VARELA M.E.; DULEY W.W.

Winnipeg

Congreso; GAC-MAC 2013; 2013

University of Manitoba- natural resource Canada

Interstellar or presolar nanodiamonds, with a mean crystallite size of 1-3 nm, were discovered by Lewis et al. (1987) in the acid-treated residues of carbonaceous chondrites. These nanodiamonds contain isotopically anomalous noble gases, particularly Xe-HL anomaly, which is enriched both in the heavy (H) and the light (L) isotopes of Xe. The origin and the process by which these presolar nanodiamonds have formed is still debated, however many authors favor the formation from a process similar to the chemical-vapor-deposition (CVD). Kapoeta is an achondrite meteorite characterized as a gas-rich polymict breccia with a light-dark structure. It belongs to the howardite group, which together with eucrites and diogenites constitute the HED meteorites, with 4 Vesta as a probable parent asteroid. Kapoeta contains mm-sized dark inclusions that are described as carbonaceous chondrite (CC) materials, which are believed to be incorporated into the HED parent body by carbanaceous meteorites impacters at a later stage of its formation. Here, we present results from a Fourier-transform infrared (FTIR) and Raman spectroscopy study on a CC material from the Kapoeta meteorite.