Continued Isotopic Studies of Presolar Graphite from Orgueil
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چکیده
منابع مشابه
Si AND Mg-Al ISOTOPIC STUDIES OF PRESOLAR GRAPHITE FROM ORGUEIL
Introduction: Last year we reported the successful isolation of presolar graphite from Orgueil and presented C, N, O and Si isotopic ratios on individual graphite grains from seven density fractions, with grain sizes > 1μm (Table 1) [1, 2]. Except for fractions ORG1b and 1h, all fractions analyzed were found to contain presolar carbonaceous grains that are morphologically and isotopically simil...
متن کاملA First Look at Graphite Grains from Orgueil: Morphology, Carbon, Nitrogen and Neon Isotopic Compositions of Individual, Chemically Separated Grains
Presolar graphite in Murchison has been extensively studied [1, 2, 3]. It is characterized by a unique Ne isotopic composition, known as the Ne-E(L) component. According to studies by Huss and Lewis [4], the concentration of Ne-E(L) in Orgueil is about one order of magnitude higher than in Murchison, when normalized to the matrix. This could be due to a higher presolar graphite abundance in Org...
متن کاملIsotopic analysis of presolar graphite grains from Orgueil
We report the successful isolation and isotopic analysis of presolar graphite grains from the Orgueil CI chondrite. Isotopic measurements were made on seven density fractions, with grain sizes >1 lm: ORG1b (1.59–1.67 g cm ), 1c (1.67–1.75 g cm ), 1d (1.75– 1.92 g cm ), 1f (2.02–2.04 g cm ), 1g (2.04–2.12 g cm ), 1h (2.12–2.16 g cm ) and 1i (2.16–2.30 g cm ). We measured C, N, O, and Si isotopes...
متن کاملContinued Study of Presolar Graphite from Murchison Separate Kfa1
Introduction: Presolar graphite was isolated from the Murchison meteorite [1] only 3 years after the discovery of presolar SiC [2]. Yet it has not been studied as extensively as SiC. One of the reasons is that trace element concentrations in graphite grains are, in general, not high enough to perform isotopic analysis with sufficient precision. A new type of ion microprobe, the NanoSIMS, has re...
متن کاملOn the stellar sources of presolar graphite
Primitive meteorites contain graphite spherules whose anomalous isotopic compositions indicate a stellar origin. The isolation of presolar graphite grains is difficult and they have been less well studied than presolar silicon carbide grains. While previous isotopic measurements have been made on graphite from the Murchison meteorite and mostly on low-density grains, a new separation of graphit...
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