Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4727472 | Gondwana Research | 2013 | 12 Pages |
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 °C–650 °C. 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.
Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Discovery of eclogite in the East Kunlun orogen. ► Estimated P-T conditions of eclogite formation at 590 °C–650 °C and > 1.6 GPa. ► Gabbro-diorite protolith formed at 934 Ma and eclogite metamorphism at 428 Ma. ► Early Paleozoic HP metamorphic zone identified in Central East Kunlun Fault.