Isotopic composition of nitrogen in the PCA 91002 R group chondrite

Nitrogen isotopic composition of an R-group chondrite PCA 91002 was measured. A delta ^N value as low as -60 permil was found in some combustion steps. Since this is a gas-rich meteorite, interpretation of the result is not straightforward, but with the aid of results on an H_2O_2-treated sample, we conclude that isotopically light nitrogen is indigenous to the meteorite

Nitrogen isotopic compositions of some solar-gas-rich chondrites

Isotopically heavy nitrogen was detected in three solar-gas-rich (Weston (H4), ALHA77278 (LL3.7) and Yamato-82133 (H3)) and one solar-gas-poor (LEW86018 (L3.1)) chondrites. Together with a previously studied solar-gas-rich chondrite, all solar-gas-rich chondrites that we examined have isotopically heavy nitrogen. Thus, we suggest that the solar nitrogen is isotopically heavy. The abundance of the heavy nitrogen is, however, not proportional to that of the solar Ne, suggesting complex processing on the surfaces of the parent bodies