Cenozoic low temperature cooling history of the eastern Lhasa terrane:Implications for high-relief topography of external drainage area in the southern Tibetan Plateau  

作　　者：Wenbo Su Zhiyuan He Linglin Zhong Stijn Glorie Kanghui Zhong Johan De Grave 

机构地区：[1]Laboratory for Mineralogy and Petrology,Department of Geology,Ghent University,Krijgslaan 281 S8,9000 Ghent,Belgium [2]College of Earth Sciences,Chengdu University of Technology,Chengdu 610059,China [3]Department of Earth Sciences,School of Physical Sciences,The University of Adelaide,SA-5005,Australia

出　　处：《Geoscience Frontiers》2023年第5期126-140,共15页地学前缘（英文版）

基　　金：supported by National Key Research and Development Program of China(2022YFC2905001,2018YFC0604105);the Opening Foundation of Ministry of Natural Resources Key Laboratory for Mineral Deposits Research,Chengdu University of Technology(grant number:gzck202104);the Fund for Scientific Research-Flanders(FWO,Bilateral Project VS06520N);China Scholarship Council(201908320260,201806190214);support for W.Su and Z.He for their research stay in Belgium.S.Glorie is supported by an Australian Research Council Future Fellowship(FT210100906)。

摘　　要：The Tibetan Plateau geographically contains internal and external drainage areas based on the distributions of river flows and catchments.The internal and external drainage areas display similar highelevations,while their topographic reliefs are not comparable;the former shows a large low-relief surface,whereas the latter is characterized by relatively high relief.The eastern Lhasa terrane is a key tectonic component of the Tibetan Plateau.It is characterized by high topography and relief,but the thermal history of its basement remains relatively poorly constrained.In this study we report new apatite fission track data from the eastern part of the central Lhasa terrane to constrain the thermo-tectonic evolution of the external drainage area in the southern Tibetan Plateau.Twenty-one new AFT ages and associated thermal history models reveal that the basement underlying the external drainage area in southern Tibet experienced three main phases of rapid cooling in the Cenozoic.The Paleocene-early Eocene(-60–48 Ma)cooling was likely induced by crustal shortening and associated rock exhumation,due to accelerated northward subduction of the NeoTethys oceanic lithosphere.A subsequent cooling pulse lasted from the late Eocene to early Oligocene(-40–28 Ma),possibly due to the thickening and consequential erosion of the Lhasa lithosphere resulted from the continuous northward indentation of the India plate into Eurasia.The most recent rapid cooling event occurred in the middle Miocene-early Pliocene(-16–4 Ma),likely induced by accelerated incision of the Lhasa River and local thrust faulting.Our AFT ages and published low-temperature thermochronological data reveal that the external drainage area experienced younger cooling events compared with the internal drainage area,and that the associated differentiated topographic evolution initiated at ca.30 Ma.The contributing factors for the formation of the high-relief topography mainly contain active surface uplift,fault activity,and the enhanced incision of the Yarlung R

关 键 词：CENOZOIC Apatite fission track thermochronology EXHUMATION Lhasa terrane External drainage area Tibetan Plateau 

分 类 号：P542[天文地球—构造地质学] P59[天文地球—地质学] P534.5