Early stages of core segregation recorded by Fe isotopes in an asteroidal mantle
Type | Article | ||||||||||||
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Date | 2015-06 | ||||||||||||
Language | English | ||||||||||||
Author(s) | Barrat Jean-Alix1, Rouxel Olivier![]() |
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Affiliation(s) | 1 : Univ Bretagne Occidentale, CNRS, UMR 6538, Inst Univ Europeen Mer, F-29280 Plouzane, France. 2 : IFREMER, Ctr Brest, F-29280 Plouzane, France. 3 : Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. 4 : Univ Paris Diderot, Inst Univ France, Inst Phys Globe Paris, Sorbonne Paris Cite, F-75238 Paris 05, France. 5 : Inst Univ France, Paris, France. 6 : Natl Inst Polar Res, Tachikawa, Tokyo 1908518, Japan. 7 : Grad Univ Adv Sci, Sch Multidisciplinary Sci, Dept Polar Sci, Tachikawa, Tokyo 1908518, Japan. 8 : Univ Munster, Inst Planetol, D-48149 Munster, Germany. 9 : CNRS, UMS 3113, IUEM, F-29280 Plouzane, France. |
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Source | Earth And Planetary Science Letters (0012-821X) (Elsevier Science Bv), 2015-06 , Vol. 419 , P. 93-100 | ||||||||||||
DOI | 10.1016/j.epsl.2015.03.026 | ||||||||||||
WOS© Times Cited | 41 | ||||||||||||
Keyword(s) | iron isotopes, achondrite, ureilite, core | ||||||||||||
Abstract | Ureilite meteorites are achondrites that are debris of the mantle of a now disrupted differentiated asteroid rich in carbon. They provide a unique opportunity to study the differentiation processes of such a body. We analyzed the iron isotopic compositions of 30 samples from the Ureilite Parent Body (UPB) including 29 unbrecciated ureilites and one ureilitic trachyandesite (ALM-A) which is at present the sole large crustal sample of the UPB. The δ56Fe of the whole rocks fall within a restricted range, from 0.01 to 0.11‰, with an average of +0.056±0.008‰+0.056±0.008‰, which is significantly higher than that of chondrites. We show that this difference can be ascribed to the segregation of S-rich metallic melts at low degrees of melting at a temperature close to the Fe–FeS eutectic, and certainly before the onset of the melting of the silicates (View the MathML source<1100°C), in agreement with the marked S depletions, and the siderophile element abundances of the ureilites. These results point to an efficient segregation of S-rich metallic melts during the differentiation of small terrestrial bodies. | ||||||||||||
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