NOBLE-GASES IN THE INTERSTELLAR DIAMOND OF EFREMOVKA C3V CHONDRITE

Noble gas content and its isotopic composition of the diamond from Efremovka C3V chondrite is studied. It is suggested that isotopically normal and anormal components formed as a result of Supernovaenuclti-synthesis were independently captured by diamond grains. It was found that the interstellar diamond in chondrite is composed of not less than two groups of grains differing in thermal oxidation resistance and elemental or isotopic composition of noble gases. Isotopically normal Xe, Kr 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 oxidation. At the same time Kr-H/Xe-H ratio of both diamond grain types is similar, its average value being 0.12 +/- 0.02. Isotopic effects of Xe and Kr could be considered as a result of mixing of isotopically normal (solar) and isotopically anomalous components generated in p- and min-r processes in Supernovae. If so, every diamond grain type should be characterised by different Xe-H isotopic composition.