Zircon SHRIMP U-Pb Ages, Hf Isotopic Features and Their Geological Significance of the Greater Himalayan Crystalline Complex Augen Gneiss in Gyirong Area, South Tibet
详细信息
- 责任者：Wang Xiaoxian (Key Laboratory of Orogenic Belts and Crustal Evolution ; Ministry of Education ; School of Earth and Space Sciences ; Peking University ; Beijing 100871 ; China) ; Zhang Jinjiang
- 刊名：Earth Science Frontiers
- 出版年：2011
- 卷期：18(2)
- 关键词：片麻岩 ; gneisses ; 铀—铅计时 ; U-Pb dating ; 铪同位素 ; hafnium isotopes ; 西藏 ; Tibet
- 页码：p.127-139
- 图表：11 illus., 2 tables, 72 refs.
- 分类号：0802
- 出版序号：20120190
- issnNo：ISSN1005-2321
- isbnNo：CN11-3370/P
摘要
The augen gneiss in the Gyirong Area of south Tibet belongs to the Greater Himalayan crystalline Complex. It consists of quartz, plagioclase, K-feldspar, biotite and minor muscovite. Zircons of the augen gneiss have core-rim structures with inherited cores and magmatic rims indicated by concentric oscillatory zoning. It implies that the source of granite came from crust, possibly resulted from partial melting of the crust in the northernmost margin of the India Craton. The zircon SHRIMP U-Pb ages, combined with the published geochronological data, demonstrate that the Himalaya is a composite orogenic belt, which underwent an early Paleozoic orogenesis. The Early Paleozoic Himalaya was an Andean-type orogen after the Gondwana assemblying, which resulted from the subduction of the proto-Tethys ocean beneath the India Plate, rather than a Pan-African orogen that was formed by the continent-continent collision during the Gondwana assembly.