s-Process signatures in bulk presolar silicon carbide: a multielement study

Isotopic and elemental abundance signatures in the mass range Sr through Hf have been determined in a silicon carbide-rich sample of the Murchison carbonaceous chondrite, using inductively-coupled plasma mass spectrometry (ICP-MS). Despite the problem of isobaric interferences useful results were obtained for a number of isotopes, several for the first time. While disagreements between astrophysical predictions and earlier results for 137Ba and 146Nd obtained by thermal ionization mass spectrometry are confirmed, our data for Dy are in line with predictions. A hint is observed for in-situ decay of 107Pd produced in the s-Process. The elemental abundance pattern shows deficits relative to production ratios of volatile elements including the more volatile Rare Earth Elements (REE). Very refractory elements including the abundant (in absolute terms) element Zr appear to be underabundant relative to refractory REE such as Nd.