Discovery of Early Paleozoic eclogite from the East Kunlun, Western China and its tectonic significance

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• 作者：Fancong Meng ; ^{mengfancong@yeah.net} ; Jianxin Zhang ; Meihui Cui
• 关键词：Eclogite ; Geochronology ; Early Paleozoic ; HP metamorphism ; East Kunlun
• 刊名：Gondwana Research
• 出版年：2013
• 出版时间：March, 2013
• 年：2013
• 卷：23
• 期：2
• 页码：825-836
• 全文大小：2391 K

文摘

Eclogites discovered in the eastern part of the East Kunlun Mountains, Western China, are primarily composed of garnet + omphacite + quartz + rutile. The garnets show end-member components of 48-55 % almandine, 1-2 % spessartine, 19-29 % grossularite and 16-29 % pyrope, and the omphacite has a jadeite content of 21-63 % . The peak-metamorphic assemblage of eclogites records a P-T condition of > 1.6 GPa and 590 ¡ãC-650 ¡ãC. Zircon U-Pb dating of the inherited magmatic zircons from fine-grained eclogite reveals a Neoproterozoic age of 934 Ma, representing the protolith age of the eclogite. Zircons from the coarse-grained eclogite contain inclusions of garnet, omphacite and rutile, and yield a weighted mean age of 428 Ma, indicating the metamorphic age of eclogite. The eclogites, together with the Late Cambrian (508 Ma) high-pressure granulite to the west, constitute an Early Paleozoic high-pressure metamorphic belt in the East Kunlun.