Early Cenozoic Tectonics of the Tibetan Plateau

• Published in: Acta geologica Sinica (Beijing) Vol. 87; no. 2; pp. 289 - 303
• Main Authors: Zhenhan, WU, Daogong, HU, Peisheng, YE, Zhonghai, WU
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.04.2013; Wiley Subscription Services, Inc; Chinese Academy of Geological Sciences, Beijing 100037, China%Institute of Geomechanics, Chinese Academy of Geological Sciences, Beijing 100081, China
• Edition: English ed.
• Subjects: Basins; paleo-elevation; paleo-tectonics; Paleocene-Eocene; Plate tectonics; subduction of the oceanic plate; the Tibetan Plateau; 中始新世; 古新世晚期; 喜马拉雅山脉; 塔里木盆地; 拉萨地块; 新生代构造; 柴达木盆地; 青藏高原中部; China, People's Rep., Xizang, Tibetan Plateau; Pakistan, Himalayas; China, People's Rep., Xizang; China, People's Rep., Qinghai Prov., Qaidam Basin; China, People's Rep., Xinjiang, Tarim Basin; paleo-elevation; subduction of the oceanic plate; paleo-tectonics; Paleocene-Eocene; the Tibetan Plateau
• ISSN: 1000-9515; 1755-6724
• DOI: 10.1111/1755-6724.12051

Geological mapping at a scale of 1：250000 coupled with related researches in recent years reveal well Early Cenozoic paleo-tectonic evolution of the Tibetan Plateau. Marine deposits and foraminifera assemblages indicate that the Tethys-Himalaya Ocean and the Southwest Tarim Sea existed in the south and north of the Tibetan Plateau, respectively, in Paleocene-Eocene. The paleo- oceanic plate between the Indian continental plate and the Lhasa block had been as wide as 900km at beginning of the Cenozoic Era. Late Paleocene transgressions of the paleo-sea led to the formation of paleo-bays in the southern Lhasa block. Northward subduction of the Tethys-Himalaya Oceanic Plate caused magma emplacement and volcanic eruptions of the Linzizong Group in 64.5-44.3 Ma, which formed the Paleocene-Eocene Gangdise Magmatic Arc in the north of Yalung-Zangbu Suture （YZS）, accompanied by intensive thrust in the Lhasa, Qiangtang, Hoh Xil and Kunlun blocks. The Paleocene- Eocene depression of basins reached to a depth of 3500-4800 m along major thrust faults and 680-850 m along the boundary normal faults in central Tibetan Plateau, and the Paleocene-Eocene depression of the Tarim and Qaidam basins without evident contractions were only as deep as 300-580 m and 600-830 m, respectively, far away from central Tibetan Plateau. Low elevation plains formed in the southern continental margin of the Tethy-Himalaya Ocean, the central Tibet and the Tarim basin in Paleocene-Early Eocene. The Tibetan Plateau and Himalaya Mts. mainly uplifted after the Indian- Eurasian continental collision in Early-Middle Eocene.