早期太阳系中富含重氧同位素的水的残余物。

Remnants of the early solar system water enriched in heavy oxygen isotopes.

作者信息

Sakamoto Naoya, Seto Yusuke, Itoh Shoichi, Kuramoto Kiyoshi, Fujino Kiyoshi, Nagashima Kazuhide, Krot Alexander N, Yurimoto Hisayoshi

机构信息

Department of Natural History Sciences, Hokkaido University, Sapporo 060-0810, Japan.

出版信息

Science. 2007 Jul 13;317(5835):231-3. doi: 10.1126/science.1142021. Epub 2007 Jun 14.

DOI:10.1126/science.1142021

PMID:17569827

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.

摘要

我们的太阳系的氧同位素组成被认为是由两个同位素不同的星云储库混合而成，相对于地球而言，一个富含16O，另一个富含（17，18）O。富含（17，18）O的储库的性质和组成受到的限制较少。我们报告了在一块原始碳质球粒陨石Acfer 094的细粒基质中普遍分布的一种化学和同位素独特的物质的原位发现。这种物质是由太阳星云或小行星上的水对铁镍金属和硫化物进行氧化形成的。这种物质的氧同位素组成表明，水高度富集17O和18O（δ（17，18）O（SMOW）= +180‰），这为早期太阳系中一个极其富含（17，18）O的储库提供了首个证据。