Petrofabric studies of eclogite, spinel‐Websterite, and spinel‐lherzolite Xenoliths from kimberlite‐bearing breccia pipes in southeastern Utah and northeastern Arizona
Petrofabric studies of eclogite, spinel‐Websterite, and spinel‐lherzolite Xenoliths from kimberlite‐bearing breccia pipes in southeastern Utah and northeastern Arizona
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DOI：
10.1029/jb077i023p04350
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发表时间：
1972-08
影响因子：
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通讯作者：
H. Helmstaedt;O. Anderson;A. T. Gavasci
中科院分区：
文献类型：
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作者：
H. Helmstaedt;O. Anderson;A. T. Gavasci
构造证据，单斜辉石织物，榴辉岩结核的矿物组合从金伯利岩角砾岩管东部科罗拉多高原是一致的起源主要是基性火成岩的变质重结晶。榴辉岩可分为三个组构，表现为线性，平面和随机组构。单斜辉石遵循与变质地壳构造岩中角闪石相似的定向规律。橄榄石的部分重结晶和广泛的后结晶应变的辉石的二辉橄榄岩和websterite被认为是由于在地壳条件下的原始组构的修改。超镁铁质结核的推断结构历史提出了各种限制岩石学模型试图解释其起源。
Textural evidence, clinopyroxene fabric, and mineral assemblages of eclogite nodules from the kimberlite-bearing breccia pipes of the east Colorado plateau are consistent with an origin by metamorphic recrystallization of predominantly basic igneous rocks. The eclogites are divided into three fabric groups exhibiting linear, planar, and random fabrics. Clinopyroxenes follow similar orientation rules as amphiboles in metamorphosed crustal tectonites. Partial recrystallization of olivine and extensive postcrystalline strain in the pyroxenes of the lherzolites and the websterites are believed to be due to a modification of the original fabric under crustal conditions. The inferred structural history of the ultramafic nodules puts various constraints on petrologic models attempting to explain their origin.