Isotopic composition of the anomalous xenon in the Murchison Meteorite

Abstract

The calculated isotopic composition of the anomalous new xenon component enriched in 128Xe, 130Xe, and 132Xe discovered by Srinivasan and Anders [1978] in Murchison depends strongly on the technique used to partition the measured spectra among the different components present in the sample. With little a priori justification, Srinivasan and Anders initially assume 134Xe and 136Xe are absent from the new component to derive a composition that matches calculated spectra of xenon produced by s‐process nucleosynthesis. The reported data when plotted on xenon three‐isotope diagrams fall on mixing lines that may be extrapolated to define an allowed range of end point compositions for the new component. This approach to the data yields a well‐defined family of unusual xenon spectra, none of which is the same as the composition obtained by Srinivasan and Anders, and none of which is directly compatible with a component of pure s‐process nucleosynthesis.