Highly Siderophile Elements and the Rhenium-Osmium System in Chondritic Components

Abstract

Chondritic meteorites and their components provide information about the early solar system, as well as processes that affected meteorite parent bodies post-accretion. The rare earth element (REE) abundances, highly siderophile element (HSE) abundances, Re-Os isotope systematics, Re isotopic composition, and Os isotopic composition were investigated in Allende chondritic components in order to: (1) classify several recently separated Allende calcium-aluminum-rich inclusions (CAIs) based on REE abundance patterns, (2) determine the abundances of six HSE (Re, Os, Ir, Ru, Pt, and Pd) in CAIs, chondrules, and matrix, and compare the different chondritic components, (3) further assess the magnitude and characteristics of open-system behavior on the Allende parent body using Re-Os of CAIs, chondrules, and matrix, (4) determine if the Re isotopic composition of CAIs was altered by cosmic ray interactions, and (5) investigate possible nucleosynthetic anomalies in CAIs.