Lithospheric strike-slip faulting in central Tibet since 35-32 Ma and implications for the incipient Asian extrusional tectonics  

作　　者：Haijian Lu Haibing Li Zhongjin Xiang Marco GMalusà Chunrui Li Zhiyong Zhang Lin Wu Xuxuan Ma Jiawei Pan 

机构地区：[1]SinoProbe Laboratory,Key Laboratory of Continental Dynamics of Ministry of Natural Resources,Institute of Geology,Chinese Academy of Geological Sciences,Beijing 100037,China [2]Jiangsu Donghai Crustal Activity in Deep Holes of the Continental Scientific Drilling National Observation and Research Station,Lianyungang 222300,China [3]Department of Earth and Environmental Sciences,University of Milano-Bicocca,Milano 20126,Italy [4]State Key Laboratory of Lithospheric Evolution,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China

出　　处：《National Science Review》2025年第2期83-97,共15页国家科学评论(英文版)

基　　金：supported by the Chinese Academy of Geological Sciences Basal Research Fund(JKYZD202307);the Second Tibetan Plateau Scientific Expedition and Research Program(2019QZKK0901);the China Geological Survey(DD20221630);the National Natural Science Foundation of China(42372274).

摘　　要：The onset age and depth of the central Tibet strike-slip faults are two sti l l unresolved fundamental issues with regard to the Cenozoic tectonic evolution of central Tibet.Here we present a comprehensive dataset of geochronological,geochemical and structural data on recently discovered en-echelon dykes representing the incipient development of strike-slip faulting from the Lunpola basin in central Tibet.Our results provide evidence for mantle-derived,bimodal magmatism linked to lithospheric-scale strike-slip faulting at 35-32 Ma,and demonstrate that the central Tibet strike-slip faults are at least 20 Ma older than previously estimated(15-8 Ma).We suggest that these faults were originally connected with the lithospheric-scale Jiali and Ailao Shan-Red River shear zones exposed farther east,forming part of a straight,2500-3000 km-long lithospheric shear zone that favored mantle upwelling and magmatic intrusion coeval with substantial uplift(1.5-2 km)of the central Tibet valley in the early Oligocene.

关 键 词：onset age shear depth strike-slip faulting bimodal dyke Lunpola basin central Tibet 

分 类 号：P31[天文地球—固体地球物理学]