title: Remnants of the early solar system water enriched in heavy oxygen isotopes.
abstract: Oxygen isotopic composition of our solar system is believed to have resulted from mixing of two isotopically distinct nebular reservoirs, 16O-rich and (17,18)O-rich relative to Earth. The nature and composition of the (17,18)O-rich reservoir are poorly constrained. We report an in situ discovery of a chemically and isotopically unique material distributed ubiquitously in fine-grained matrix of a primitive carbonaceous chondrite Acfer 094. This material formed by oxidation of Fe,Ni-metal and sulfides by water either in the solar nebula or on a planetesimal. Oxygen isotopic composition of this material indicates that the water was highly enriched in 17O and 18O (delta(17,18)O(SMOW) = +180 per thousand per mil), providing the first evidence for an extremely (17,18)O-rich reservoir in the early solar system.
authors.affiliation: Department of Natural History Sciences, Hokkaido University, Sapporo 060-0810, Japan.
authors.forename: Naoya
authors.initials: N
authors.lastname: Sakamoto
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Seto
authors.forename: Shoichi
authors.initials: S
authors.lastname: Itoh
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Kuramoto
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Fujino
authors.forename: Kazuhide
authors.initials: K
authors.lastname: Nagashima
authors.forename: Alexander N
authors.initials: AN
authors.lastname: Krot
authors.forename: Hisayoshi
authors.initials: H
authors.lastname: Yurimoto
mesh_terms: D019110:Meteoroids; D010084:Oxidation-Reduction; D010100:Oxygen / Q000032:analysis*; D010103:Oxygen Isotopes / Q000032:analysis*; D016082:Solar System; D014867:Water / Q000737:chemistry*
chemical_list: D010103:Oxygen Isotopes; D014867:Water; D010100:Oxygen