55 Million years of Continent-Ocean Tectonics in Eastern Asia

Paul Tapponnier

National Institute of Natural Hazards, MEMC

(EOS, Singapore; IPGP, Paris)

2021.05.14 （星期五）15:00，理科二号楼2821

Abstract

How the Indian collision deformed eastern Asia, uplifting Tibet and surrounding mountains and generating large strike-slip faults and rifts remains debated. The potential roles of processes including channel flow, orogenic collapse, or delamination are unclear, and modelling 3D deformation since collision began has been a challenge.

Indisputable evidence, however, now places first order kinematic and timing constraints that are sufficient to identify the main mechanisms at play. On a continental-scale, the bulk of the lithospheric deformation appears to have been taken-up by long, narrow faults/shear-zones with large offsets. While they evolved in time, movements along such faults appear to have been closely inter-connected in the continent and adjacent oceanic basins. We discuss here the northeast-wards, stepwise growth of such large faults, and of associated mountains and plateaus. The opening of the Tertiary Seas and other basins around Southeast Asia was intimately linked with faulting inside the continent. To a first order, it is possible to reconstruct the formation of most such basins as a direct consequence of motion along large strike-slip faults activated in sequence with partial overlap. From ≈ 45 Ma onwards, such faults played the leading role in transforming collisional shortening north of India into extension and seafloor spreading east and south of it. After ≈ 10 Ma, broad-scale stress/strain inversion led to present-day faulting in most areas, including along the recent margins. Such a revisited extrusion model provides a self-consistent regional framework to further investigate the geological evolution of the post Paleogene ranges and basins across the entire southeast corner of Asian.

Biography of the speaker

    Paul Tapponnier教授：国家自然灾害防治研究院特聘研究员，学位评定委员会副主任，科学技术委员会特聘委员，法国科学院和美国科学院院士。曾任巴黎地球物理研究所大地构造研究室主任，新加坡南洋理工大学教授。Paul Tapponnier教授对板块构造理论作出了巨大贡献，成果卓著并获如下殊荣：1984年获法国国家科学中心银质奖章，1985年获欧洲地球科学学会“魏格纳”勋章；1990年巴黎拉维尔科学奖章；1991年法国国家荣誉军团骑士勋章；1994年美国地质学会最佳论文奖；1996年美国地质学会荣誉院士；1998年获中国友谊奖章；2005年美国国家科学院外籍院士；2005年法国科学院院士；2011年中国科学院爱因斯坦讲席教授；2012年尼泊尔地质学会荣誉会员；2018年亚洲大洋洲地球科学学会艾克斯福德奖章等。

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