Protracted core formation and rapid accretion of protoplanets
Protracted core formation and rapid accretion of protoplanets
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DOI：
10.1126/science.1251766
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发表时间：
2014-06-06
期刊：
影响因子：
56.9
通讯作者：
Kleine, T.
中科院分区：
文献类型：
--
作者：
Kruijer, T. S.;Touboul, M.;Kleine, T.
了解陨石母体中的核心形成对于限制太阳原行星盘内原行星吸积和分化的基本过程至关重要。我们报告的变化5至百万分之20的W-182，从现在灭绝的Hf-182的衰变，在五个岩浆铁陨石群。这些W-182的变化表明，核心的形成发生在一个类似的间隔100万年，并可能涉及早期分离的Fe-FeS和后来分离的铁熔体。尽管核心形成的时间间隔很长，但铁陨石母体可能在富含Ca-Al的包裹体形成后的10万至30万年内同时增生。因此，这些天体中挥发性成分的变化并不是由不完全凝聚的太阳星云在不同时间的吸积造成的，而是反映了星云内部的局部过程。
Understanding core formation in meteorite parent bodies is critical for constraining the fundamental processes of protoplanet accretion and differentiation within the solar protoplanetary disk. We report variations of 5 to 20 parts per million in W-182, resulting from the decay of now-extinct Hf-182, among five magmatic iron meteorite groups. These W-182 variations indicate that core formation occurred over an interval of similar to 1 million years and may have involved an early segregation of Fe-FeS and a later segregation of Fe melts. Despite this protracted interval of core formation, the iron meteorite parent bodies probably accreted concurrently similar to 0.1 to 0.3 million years after the formation of Ca-Al-rich inclusions. Variations in volatile contents among these bodies, therefore, did not result from accretion at different times from an incompletely condensed solar nebula but must reflect local processes within the nebula.