000205512 001__ 205512
000205512 005__ 20180317093725.0
000205512 0247_ $$2doi$$a10.1073/pnas.1418889111
000205512 022__ $$a0027-8424
000205512 02470 $$2ISI$$a000345920800025
000205512 037__ $$aARTICLE
000205512 245__ $$aSilicon isotopes in angrites and volatile loss in planetesimals
000205512 260__ $$aWashington$$bNatl Acad Sciences$$c2014
000205512 269__ $$a2014
000205512 300__ $$a4
000205512 336__ $$aJournal Articles
000205512 520__ $$aInner solar system bodies, including the Earth, Moon, and asteroids, are depleted in volatile elements relative to chondrites. Hypotheses for this volatile element depletion include condensation from the solar nebula and volatile loss during energetic impacts. These processes are expected to each produce characteristic stable isotope signatures. However, processes of planetary differentiation may also modify the isotopic composition of geochemical reservoirs. Angrites are rare meteorites that only a few million years after calcium-aluminum-rich inclusions and exhibit extreme depletions in volatile elements relative to chondrites, making them ideal samples with which to study volatile element depletion in the early solar system. Here we present high-precision Si isotope data that show angrites are enriched in the heavy isotopes of Si relative to chondritic meteorites by 50-100 ppm/amu. Silicon is sufficiently volatile such that it may be isotopically fractionated during incomplete condensation or evaporative mass loss, but theoretical calculations and experimental results also predict isotope fractionation under specific conditions of metal-silicate differentiation. We show that the Si isotope composition of angrites cannot be explained by any plausible core formation scenario, but rather reflects isotope fractionation during impact-induced evaporation. Our results indicate planetesimals initially formed from volatile-rich material and were subsequently depleted in volatile elements during accretion.
000205512 6531_ $$avolatiles
000205512 6531_ $$aaccretion
000205512 6531_ $$aisotopes
000205512 6531_ $$aangrites
000205512 6531_ $$asilicon
000205512 700__ $$aPringle, Emily A.$$uUniv Paris Diderot, Sorbonne Paris Cite, Inst Phys Globe Paris, F-75005 Paris, France
000205512 700__ $$aMoynier, Frederic$$uUniv Paris Diderot, Sorbonne Paris Cite, Inst Phys Globe Paris, F-75005 Paris, France
000205512 700__ $$aSavage, Paul S.$$uUniv Paris Diderot, Sorbonne Paris Cite, Inst Phys Globe Paris, F-75005 Paris, France
000205512 700__ $$0246015$$aBadro, James$$g221567$$uUniv Paris Diderot, Sorbonne Paris Cite, Inst Phys Globe Paris, F-75005 Paris, France
000205512 700__ $$aBarrat, Jean-Alix
000205512 773__ $$j111$$k48$$q17029-17032$$tProceedings Of The National Academy Of Sciences Of The United States Of America
000205512 909CO $$ooai:infoscience.tind.io:205512$$particle$$pSB
000205512 909C0 $$0252407$$pEPSL
000205512 909c0 $$xU12330
000205512 937__ $$aEPFL-ARTICLE-205512
000205512 973__ $$aEPFL$$rREVIEWED$$sPUBLISHED
000205512 980__ $$aARTICLE