NOBLE-GASES IN THE INTERSTELLAR DIAMOND O F EFREMOVKA C3V CHONDRITE

Noble gas content and its isotopic composition of the diamond from Efr emovka C3V chondrite is studied. It is suggested that isotopically nor mal and anormal components formed as a result of Supernovaenuclti-synt hesis were independently captured by diamond grains. It was found that the interstellar diamond in chondrite is composed of not less than tw o groups of grains differing in thermal oxidation resistance and eleme ntal or isotopic composition of noble gases. Isotopically normal Xe, K r and Ar in diamond grains of low oxidation temperature (580-degrees-C ) were found to be less intensively fractionated in relation to solar gas in comparison to that of grains being more resistant to the oxidat ion. At the same time Kr-H/Xe-H ratio of both diamond grain types is s imilar, its average value being 0.12 +/- 0.02. Isotopic effects of Xe and Kr could be considered as a result of mixing of isotopically norma l (solar) and isotopically anomalous components generated in p- and mi n-r processes in Supernovae. If so, every diamond grain type should be characterised by different Xe-H isotopic composition.