Origin of rims on coarse-grained inclusions in the Allende meteorite.
Origin of rims on coarse-grained inclusions in the Allende meteorite.
复制标题
阿连德陨石中粗粒包裹体边缘的起源。
DOI：
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发表时间：
1982
期刊：
影响因子：
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通讯作者：
J. M. Allen
中科院分区：
文献类型：
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作者：
G. MacPherson;L. Grossman;J. Beckett;J. M. Allen
阿连德陨石中的粗粒富钙包裹体被一系列非常薄的、矿物学上不同的边缘层所包围。出现了一些问题与轮辋的存在。目前的调查提出了新的意见，对所有这些问题的影响，并提供了一个模型的形成轮辋。分区蚀变脉被认为是沿着与弯曲的包裹体，尖晶石-钙钛矿-黄长石带（SP），覆盖层黄长石丰富的SP侧，覆盖层尖晶石丰富的SP侧，以及边缘组成和粗粒包裹体的蚀变程度方面。粗粒包裹体上的边缘是在一个非平衡过程中形成的，该过程涉及粗粒黄长石和尖晶石之间的反应以及星云状气相，该气相也在这些包裹体的内部产生次生蚀变产物。
Coarse-grained, calcium-rich inclusions in the Allende meteorite are enclosed by sequences of very thin, mineralogically distinct rim layers. A number of questions arise in connection with the presence of rims. The present investigation presents new observations bearing on all these questions and provides a model for the formation of rims. A zoned alteration vein is considered along with a sinuous inclusion, a spinel-perovskite-melilite band (SP), layers overlying the melilite-rich side of SP, a layer overlying the spinel-rich side of SP, and aspects of rim composition and the degree of alteration in coarse-grained inclusions. It is proposed that rims on coarse-grained inclusions formed in a nonequilibrium process involving those reactions between coarse-grained melilite and spinel and a nebular gas phase which also produced the secondary alteration products in the interiors of these inclusions.