title: Magmatic record of India-Asia collision.
abstract: New geochronological and geochemical data on magmatic activity from the India-Asia collision zone enables recognition of a distinct magmatic flare-up event that we ascribe to slab breakoff. This tie-point in the collisional record can be used to back-date to the time of initial impingement of the Indian continent with the Asian margin. Continental arc magmatism in southern Tibet during 80-40 Ma migrated from south to north and then back to south with significant mantle input at 70-43 Ma. A pronounced flare up in magmatic intensity (including ignimbrite and mafic rock) at ca. 52-51 Ma corresponds to a sudden decrease in the India-Asia convergence rate. Geological and geochemical data are consistent with mantle input controlled by slab rollback from ca. 70 Ma and slab breakoff at ca. 53 Ma. We propose that the slowdown of the Indian plate at ca. 51 Ma is largely the consequence of slab breakoff of the subducting Neo-Tethyan oceanic lithosphere, rather than the onset of the India-Asia collision as traditionally interpreted, implying that the initial India-Asia collision commenced earlier, likely at ca. 55 Ma.
authors.affiliation: State Key Laboratory of Geological Processes and Mineral Resources, and School of Earth Science and Resources, China University of Geosciences, Beijing 100083, China.
authors.forename: Di-Cheng
authors.initials: DC
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Geological Processes and Mineral Resources, and School of Earth Science and Resources, China University of Geosciences, Beijing 100083, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Geological Processes and Mineral Resources, and School of Earth Science and Resources, China University of Geosciences, Beijing 100083, China.
authors.forename: Zhi-Dan
authors.initials: ZD
authors.lastname: Zhao
authors.affiliation: Institute of Earth Sciences, Academia Sinica, Taipei 11529, Taiwan.|Department of Geosciences, National Taiwan University, Taipei 10617, Taiwan.
authors.forename: Sun-Lin
authors.initials: SL
authors.lastname: Chung
authors.affiliation: Department of Earth Sciences, University of St Andrews, North Street, St Andrews KY16 9AL, UK.|Centre for Exploration Targeting, School of Earth and Environment, University of Western Australia, 35 Stirling Hwy., Crawley WA, 6009, Australia.
authors.forename: Peter A
authors.initials: PA
authors.lastname: Cawood
authors.affiliation: State Key Laboratory of Geological Processes and Mineral Resources, and School of Earth Science and Resources, China University of Geosciences, Beijing 100083, China.|Department of Earth Sciences, Durham University, Durham DH1 3LE, UK.
authors.forename: Yaoling
authors.initials: Y
authors.lastname: Niu
authors.affiliation: State Key Laboratory of Geological Processes and Mineral Resources, and School of Earth Science and Resources, China University of Geosciences, Beijing 100083, China.
authors.forename: Sheng-Ao
authors.initials: SA
authors.lastname: Liu
authors.affiliation: Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China.
authors.forename: Fu-Yuan
authors.initials: FY
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Geological Processes and Mineral Resources, and School of Earth Science and Resources, China University of Geosciences, Beijing 100083, China.
authors.forename: Xuan-Xue
authors.initials: XX
authors.lastname: Mo