Isotopic compositions of different presolar silicon carbide size fractions from the Murchison meteorite
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چکیده
منابع مشابه
s-PROCESS Sr ISOTOPIC COMPOSITIONS IN PRESOLAR SiC FROM THE MURCHISON METEORITE
We have used thermal ionization mass spectrometry to measure the isotopic compositions of Sr in size-sorted samples (the KJ series) of interstellar SiC separated from the Murchison meteorite. The Sr compositions are radically anomalous in comparison to those in normal solar system materials. As for other heavy elements in presolar SiC, the anomalies can be understood to represent enrichment of ...
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Introduction: Ne-E(L) is one of the anomalous noble gas components that ultimately led to the discovery of presolar grains in meteorites. The component is extremely enriched in 22 Ne and this fact prompted the idea that the 22 Ne is from the decay of 22 Na [1]. The carrier of Ne-E(L) is presolar graphite [2], which has been extracted from Murchison [3] and Orgueil [4]. There are four graphite-r...
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We report the results of a study of 81 micrometer-sized presolar SiC grains in the size range 0.5–2.6 m from the Murchison (CM2) carbonaceous chondrite. We describe a simple, nondestructive physical disaggregation technique used to isolate the grains while preserving them in their pristine state, as well as the scanning electron microscopy energy-dispersive X-ray mapping procedure used to locat...
متن کاملCarbon, Nitrogen, and Silicon Isotopic Ratios in Kjg Presolar Sic Grains from Murchison
Introduction: SiC is the best-studied type of presolar grains [1]. Thousands of individual grains have been measured for their C and Si isotopic compositions [2-4] and many of these have been measured for additional isotopic systems, as well. Despite this wealth of data and the fact that Ti is one of the most abundant trace elements in SiC, only approximately 110 SiC grains have had their Ti is...
متن کاملIron and Nickel Isotopic Compositions of Silicon Carbide Z Grains
Introduction: Most presolar SiC grains (~93%) have Si isotopic ratios that fall along the so-called mainstream correlation line of 1.37 on a Si three isotope plot [1]. Z grains, which constitute only ~1% of the total presolar SiC population, plot on the 30 Si-rich side of this line and typically have negative δ 29 Si/ 28 Si values, suggesting that they originated in asymptotic giant branch star...
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ژورنال
عنوان ژورنال: Meteoritics & Planetary Science
سال: 2000
ISSN: 1086-9379,1945-5100
DOI: 10.1111/j.1945-5100.2000.tb01488.x