%0 Journal Article %T Pristine extraterrestrial material with unprecedented nitrogen isotopic variation %+ Laboratoire de Minéralogie et Cosmochimie du Muséum (LMCM) %+ Dipartimento di Astronomia e Scienza dello Spazio %+ Laboratoire de structures et propriétés de l'état solide - UMR 8008 (LSPES) %+ Laboratoire de Planétologie de Grenoble (LPG) %A Briani, Giacomo %A Gounelle, Matthieu %A Marrocchi, Yves %A Mostefaoui, Smail %A Leroux, Hugues %A Quirico, Eric %A Meibom, Anders %Z Program Nationale de Planetologie (PNP); the European grant ORIGINS [MRTN-ct-2006-035519]; CNRS; Région Île de France; Ministère délégué à l'Enseignement supérieur et à la Recherche; Muséum National d'Histoire Naturelle %< avec comité de lecture %@ 0027-8424 %J Proceedings of the National Academy of Sciences of the United States of America %I National Academy of Sciences %V 106 %N 26 %P 10522-10527 %8 2009 %D 2009 %R 10.1073/pnas.0901546106 %K isotopic fractionation %K pristine meteorites %K Solar SystemJournal articles %X Pristine meteoritic materials carry light element isotopic fractionations that constrain physiochemical conditions during solar system formation. Here we report the discovery of a unique xenolith in the metal-rich chondrite Isheyevo. Its fine-grained, highly pristine mineralogy has similarity with interplanetary dust particles (IDPs), but the volume of the xenolith is more than 30,000 times that of a typical IDP. Furthermore, an extreme continuum of N isotopic variation is present in this xenolith: from very light N isotopic composition (δ15NAIR = −310 ± 20‰), similar to that inferred for the solar nebula, to the heaviest ratios measured in any solar system material (δ15NAIR = 4,900 ± 300‰). At the same time, its hydrogen and carbon isotopic compositions exhibit very little variation. This object poses serious challenges for existing models for the origin of light element isotopic anomalies. %G English %L insu-00367907 %U https://insu.hal.science/insu-00367907 %~ INSU %~ MNHN %~ UGA %~ CNRS %~ UNIV-GRENOBLE1 %~ OSUG %~ ALLIANCE-SU