EARLY SOLAR-SYSTEM AQUEOUS ACTIVITY - SR ISOTOPE EVIDENCE FROM THE ORGUEIL CI METEORITE
EARLY SOLAR-SYSTEM AQUEOUS ACTIVITY - SR ISOTOPE EVIDENCE FROM THE ORGUEIL CI METEORITE
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DOI：
10.1038/307249a0
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发表时间：
1984-01-01
期刊：
影响因子：
64.8
通讯作者：
KERRIDGE, JF
中科院分区：
文献类型：
--
作者：
MACDOUGALL, JD;LUGMAIR, GW;KERRIDGE, JF
CI陨石是罕见但重要的天体，因为它们可能代表了我们太阳系化学未分馏物质的最佳样本（例如，参见参考文献1）。尽管这些陨石表面上保留了其原始的化学成分，但它们显然含有次生矿物相，至少有一些被认为是通过液态水对母体的作用产生的。然而，这一事件发生的时间不详。为了解决这个问题，我们测定了Orgueil陨石中碳酸盐和硫酸盐的Sr同位素组成和~（87）Rb/~（86）Sr。这两个相可能从水溶液中沉淀出来。我们的第一个结果，在这里报告，表明碳酸盐沉积发生在同一时期的母体形成或不久后，可能在1亿年。另一方面，至少有一些硫酸钙似乎是最近形成的。
The CI meteorites are rare but important objects because they may represent our best sample of chemically unfractionated Solar System material (see, for example, ref. 1). Despite the fact that these meteorites apparently retain their original chemical composition, they clearly contain secondary mineral phases, some at least believed to have been produced through the action of liquid water on the parent body2–6. The timing of this event, however, was unknown. In an attempt to solve this problem, we have measured the Sr isotopic composition and87Rb/86Sr in carbonates and sulphate separated from the Orgueil meteorite. Both of these phases probably precipitated from aqueous solution. Our first results, reported here, show that carbonate deposition occurred contemporaneously with parent body formation or shortly after it, probably within 100 Myr. On the other hand, at least some of the calcium sulphate seems to have been formed recently.