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Paper: Microstructural Investigations of the Cosmochemical Histories of Presolar Grains
Volume: 341, Chondrites and the Protoplanetary Disk
Page: 645
Authors: Stroud, R.M.
Abstract: Presolar grains are the remnants of the dusty materials from which our solar system formed. These grains, which escaped heavy processing in the early solar nebula and retain isotopic signatures of presolar stellar origins, are trace constituents of meteorites and interplanetary dust particles. The compositions and microstructures of the grains are a record of circumstellar dust condensation processes, overprinted with a record of processing events that occurred in the interstellar medium, solar nebula, meteorite parent body or host interplanetary dust particle, and laboratory. Possible alteration processes include: radiation damage, heating, shock, oxidation, aqueous alteration, and acid etching. The probability of a given grain retaining a signature of one or more processing events depends on the properties of the phase. Among the known presolar phases, silicates are the most readily altered, and diamond and Al2O3 the least. Recent advances in laboratory instrumentation permit the analysis of distinct processing signatures in individual presolar grains, in order to complement astrophysical observations and theoretical models of cosmic dust processing.
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