Interplay between oceanic subduction and continental collision in building continental crust

Di Cheng Zhu, Qing Wang, Roberto F. Weinberg, Peter A. Cawood, Sun Lin Chung, Yong Fei Zheng, Zhidan Zhao, Zeng Qian Hou, Xuan Xue Mo

Research output: Contribution to journalArticleResearchpeer-review

43 Citations (Scopus)

Abstract

Generation of continental crust in collision zones reflect the interplay between oceanic subduction and continental collision. The Gangdese continental crust in southern Tibet developed during subduction of the Neo-Tethyan oceanic slab in the Mesozoic prior to reworking during the India-Asia collision in the Cenozoic. Here we show that continental arc magmatism started with fractional crystallization to form cumulates and associated medium-K calc-alkaline suites. This was followed by a period commencing at ~70 Ma dominated by remelting of pre-existing lower crust, producing more potassic compositions. The increased importance of remelting coincides with an acceleration in the convergence rate between India and Asia leading to higher basaltic flow into the Asian lithosphere, followed by convergence deceleration due to slab breakoff, enabling high heat flow and melting of the base of the arc. This two-stage process of accumulation and remelting leads to the chemical maturation of juvenile continental crust in collision zones, strengthening crustal stratification.

Original languageEnglish
Article number7141
Number of pages10
JournalNature Communications
Volume13
Issue number1
DOIs
Publication statusPublished - Dec 2022

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