Thermochronological Constraints on Cenozoic Tectonic Evolution of South-Central Qinghai-Tibet Plateau
Zhu Xiaoqing
Guo Xingwei
Zhang Xunhua
Hou Fanghui
Wen Zhenhe
Geng Wei
Wang Zhonglei
Sun Jianwei
Qi Jianghao
Abstract：The spatial and temporal characteristics of the uplift in the Qinghai-Tibet Plateau since the Cenozoic has long been de-bated.Medium-and low-temperature thermochronological analysis on the base rocks plays an important role in detecting the uplifting processes of the plateau.Here we collected 15 intermediate-acid and metamorphic rock samples distributed in the Ti-betan Plateau.Zircon and apatite fission track (ZFT and AFT)analyses were performed on these samples in order to provide constraints on the uplifting process of the plateau since the Mesozoic.10 samples'ZFT results show that the ZFT ages range from 182 Ma to 33 Ma,probably recording collisions among different terranes or tectonothermal events in the Tibetan plateau before the Oligocene.Specially,ZFT ages of 3 samples distributed around the Yarlung Zangbo suture zone range from Late Eo- cene to Early Oligocene,which implies that a hard continent-continent collision occurred during ca.36 to ca.33 Ma.The Neo-cene ages dominate the AFT results,varying from 70.4 Ma to 5.0 Ma.Combined with the AFT reversed modeling results,it is concluded that southern part of Qinghai-Tibet Plateau has apparently experienced uplift since the Middle-Late Miocene.The up-lift rates increased rapidly after ca.5 Ma to ca.4 Ma.The AFT ages become younger towards southeastern part of the Qinghai-Tibetan Plateau,implying the India and Asia continent collision controls the uplifting process of the Tibetan Plateau.Addition-ally,the central part of the plateau might have reached high altitude in the Late Cretaceous-Eocene and have kept very low de-nudation rate up to now.
Keywords：Tibet Plateauthermochronologythermal reversed modelingCenozoichard collisionstructural geology
Publication Date：2018-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：18( 1903-1920 )