Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
, 2020

Evidence of Presolar SiC in the Allende Curious Marie Calcium Aluminum Rich Inclusion

Affiliations

Evidence of Presolar SiC in the Allende Curious Marie Calcium Aluminum Rich Inclusion

O Pravdivtseva et al. Nat Astron.

Abstract

Calcium aluminum rich inclusions (CAIs) are one of the first solids to have condensed in the solar nebula, while presolar grains formed in various evolved stellar environments. It is generally accepted that CAIs formed close to the Sun at temperatures above 1500 K, where presolar grains could not survive, and were then transported to other regions of the nebula where the accretion of planetesimals took place. In this context, a commonly held view is that presolar grains are found solely in the fine-grained rims surrounding chondrules and in the low-temperature fine-grained matrix that binds the various meteoritic components together. Here we demonstrate, based on noble gas isotopic signatures, that presolar SiC have been incorporated into fine-grained CAIs in the Allende carbonaceous chondrite at the time of their formation, and have survived parent body processing. This finding provides new clues on the conditions in the nascent solar system at the condensation of first solids.

Similar articles

See all similar articles

References

    1. Black DC & Pepin RO Trapped neon in meteorites – II. Earth & Planet, Sci. Letters 6, 395–405 (1969).
    1. Lewis RS, Srinivasan B & Anders E Host phase of a strange xenon component in Allende. Science 190, 1251–1262 (1975).
    1. Srinivasan B & Anders E Noble gases in the Murchison meteorite. Science 201, 51–56 (1978). - PubMed
    1. Tang M & Anders E Isotopic anomalies of Ne, Xe, and C in meteorites. II Interstellar diamond and SiC: Carriers of exotic noble gases. Geochim. Cosmochim. Acta 52, 1235–1244 (1988).
    1. Lewis RS, Amari S, & Anders E Meteoritic silicon carbide: pristine material from carbon stars. Nature 348, 293–298 (1990).
Feedback