GR focus review Metamorphism and tectonic evolution of the Lhasa terrane, Central Tibet Z.M. Zhang a, ⁎, X. Dong a , M. Santosh b, c , G.C. Zhao d a State Key Laboratory of Continental Tectonic and Dynamics, Institute of Geology, Chinese Academy of Geological Science, No. 26 Baiwanzhuang Road, Beijing 100037, China b Division of Interdisciplinary Science, Faculty of Science, Kochi University, Akebono-cho, Kochi 780-8520, Japan c School of Earth Science and Resources, China University of Geosciences Beijing, No. 29 Xueyuan Road, Haidian District, Beijing, 100083, China d Department of Earth Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China abstract article info Article history: Received 31 May 2012 Received in revised form 27 August 2012 Accepted 31 August 2012 Available online 2 October 2012 Handling Editor. S. Kwon Keywords: Metamorphism Orogeny Tectonics Lhasa terrane Central Tibet The Lhasa terrane in southern Tibet is composed of Precambrian crystalline basement, Paleozoic to Mesozoic sedimentary strata and Paleozoic to Cenozoic magmatic rocks. This terrane has long been accepted as the last crustal block to be accreted with Eurasia prior to its collision with the northward drifting Indian continent in the Cenozoic. Thus, the Lhasa terrane is the key for revealing the origin and evolutionary history of the Himalayan– Tibetan orogen. Although previous models on the tectonic development of the orogen have much evidence from the Lhasa terrane, the metamorphic history of this terrane was rarely considered. This paper provides an overview of the temporal and spatial characteristics of metamorphism in the Lhasa terrane based mostly on the recent re- sults from our group, and evaluates the geodynamic settings and tectonic significance. The Lhasa terrane experi- enced multistage metamorphism, including the Neoproterozoic and Late Paleozoic HP metamorphism in the oceanic subduction realm, the Early Paleozoic and Early Mesozoic MP metamorphism in the continent–continent collisional zone, the Late Cretaceous HT/MP metamorphism in the mid-oceanic ridge subduction zone, and two stages of Cenozoic MP metamorphism in the thickened crust above the continental subduction zone. These meta- morphic and associated magmatic events reveal that the Lhasa terrane experienced a complex tectonic evolution from the Neoproterozoic to Cenozoic. The main conclusions arising from our synthesis are as follows: (1) The Lhasa block consists of the North and South Lhasa terranes, separated by the Paleo-Tethys Ocean and the subsequent Late Paleozoic suture zone. (2) The crystalline basement of the North Lhasa terrane includes Neoproterozoic oceanic crustal rocks, representing probably the remnants of the Mozambique Ocean derived from the break-up of the Rodinia supercontinent. (3) The oceanic crustal basement of North Lhasa witnessed a Late Cryogenian (~650 Ma) HP metamorphism and an Early Paleozoic (~485 Ma) MP metamorphism in the subduction realm associated with the closure of the Mozambique Ocean and the final amalgamation of Eastern and Western Gondwana, suggesting that the North Lhasa terrane might have been partly derived from the northern segment of the East African Orogen. (4) The northern margin of Indian continent, including the North and South Lhasa, and Qiangtang terranes, experienced Early Paleozoic magmatism, indicating an Andean-type orogeny that resulted from the subduction of the Proto-Tethys Ocean after the final amalgamation of Gondwana. (5) The Lhasa and Qiangtang terranes witnessed Middle Paleozoic (~360 Ma) magmatism, suggesting an Andean-type orogeny de- rived from the subduction of the Paleo-Tethys Ocean. (6) The closure of Paleo-Tethys Ocean between the North and South Lhasa terranes and subsequent terrane collision resulted in the formation of Late Permian (~260 Ma) HP metamorphic belt and Triassic (220 Ma) MP metamorphic belt. (7) The South Lhasa terrane experienced Late Cretaceous (~90 Ma) Andean-type orogeny, characterized by the regional HT/MP metamorphism and coeval intrusion of the voluminous Gangdese batholith during the northward subduction of the Neo-Tethyan Ocean. (8) During the Early Cenozoic (55–45 Ma), the continent–continent collisional orogeny has led to the thickened crust of the South Lhasa terrane experiencing MP amphibolite-facies metamorphism and syn-collisional magmatism. (9) Following the continuous continent convergence, the South Lhasa terrane also experienced MP metamorphism during Late Eocene (40–30 Ma). (10) During Mesozoic and Cenozoic, two different stages of paired metamorphic belts were formed in the oceanic or continental subduction zones and the middle and lower crust of the hanging wall of the subduction zone. The tectonic imprints from the Lhasa terrane provide ex- cellent examples for understanding metamorphic processes and geodynamics at convergent plate boundaries. © 2012 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved. Gondwana Research 25 (2014) 170–189 ⁎ Corresponding author. Tel./fax: +86 10 68999735. E-mail address: zzm2111@sina.com (Z.M. Zhang). 1342-937X/$ – see front matter © 2012 International Association for Gondwana Research. Published by Elsevier B.V. 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