Mass Spectrometric Studies of Undifferentiated Meteorites

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A variety of mass spectrometric analyses of undifferentiated meteorites will be conducted to study the conditions, processes and timescales involved in the early history of the solar system and in the formation of planetary bodies. The samples will be both whole rock and seperated phases, notably phosphates. The analyses will include coordinated application of both noble gas and thermal emission mass spectrometry. The research is organized into three related projects: 1) An attempt will be made to determine the cosmic abundance of Pu-244 based on analysis of fission Xe in undifferentiated meteorites, 2) Rb, Sr, and Sr-87/Sr-86 in low Rb/Sr phases of chondrites will be determined in order identify initial Sr-87/Sr-86 ratios and constrain the duration of 'metamorphism' for these meteorites, 3) Noble gas abundances in chondrites will be measured using isotope dilution rather than the conventional peak-height comparison technique. This should give an order-of-magnitude improvement in accuracy. The PIs will collaborate in these analyses with Lugmair at Scripps, Burnett at Cal Tech, and Pellas at Paris.