Variations in the Ratios of the Four Stable Sulphur Isotopes in Meteorites and their Relation to Chemical and Nuclear Effects

Abstract

The isotopic ratios S33/S32, S34/S32 and S36/S32 of different forms of sulphur in a number of meteorites have been studied. The results obtained indicate that processes of chemical fractionation have occurred in some meteorites but that the isotopic composition of the total sulphur in a single meteorite is remarkably constant from meteorite to meteorite. The relationships between the S33, S34 and S36 isotope abundances indicate that variations in these abundances due to inhomogeneities in the processes of nucleo-synthesis are not detectable. Isotopic analysis of sulphur from the iron phase of the Clark County, Pinon and Tlacotepic meteorites has shown the presence of cosmic ray induced spallation S36 and S33. These spallation results are in reasonable agreement with predictions based on production rates of other nuclei.