Late Triassic Intracontinental Deformation of South Tianshan,Central Asia:Evidence from Syn-tectonic Sedimentation and Detrital Zircon Provenances of the Kuqa Depression  

作　　者：QIN Xiang CHEN Xuanhua SHAO Zhaogang ZHANG Yiping WANG Yongchao LI Bing SU He WANG Ye LIU Kui HAN Lele 

机构地区：[1]China Aero Geophysical Survey and Remote Sensing Center for Natural Resources,Beijing 100083,China [2]Key Laboratory of Airborne Geophysics and Remote Sensing Geology,MNR,Beijing 100083,China [3]Chinese Academy of Geological Sciences,Beijing 100037,China [4]School of Earth Sciences and Resources,China University of Geosciences(Beijing),Beijing 100083,China

出　　处：《Acta Geologica Sinica(English Edition)》2024年第3期548-568,共21页地质学报（英文版）

基　　金：supported by the National Key Research and Development Project(Grant No.2018YFC0603700);research grants from the China Geological Survey(Grant Nos.DD20230408,DD20190011,DD20191011 and DD20221824);the Fundamental Research Funds from the Chinese Academy of Geological Sciences(Grant No.JKY202011);the Key Laboratory of Airborne Geophysics and Remote Sensing Geology Ministry of Natural Resources(Grant No.2023YFL23)。

摘　　要：The Tianshan range,a Paleozoic orogenic belt in Central Asia,has undergone multiple phases of tectonic activities characterized by the N-S compression after the early Mesozoic,including the far-field effects of the Cenozoic Indian-Asian collision.However,there are limited reports on the tectonic deformation and initiation of Triassic intracontinental deformation in the Tianshan range.Understanding this structural context is crucial for interpreting the early intracontinental deformation history of the Eurasian continent during the early Mesozoic.Growth strata and syn-tectonic sediments provide a rich source of information on tectonic activities and have been extensively used in the studies of orogenic belts.Based on detail fieldwork conducted in this study,the middle-late Triassic Kelamayi Formation of the northern Kuqa Depression in the southern Tianshan fold-thrust belt has been identified as the typical syn-tectonic growth strata.The youngest detrital zircon component in two lithic sandstone samples from the bottom and top of the Kelamayi growth strata yielded U-Pb ages of 223.4±3.1 and 215.5±2.9 Ma,respectively,indicating that the maximum depositional age of the bottom and top of the Kelamayi growth strata is 226-220 and 218-212 Ma.The geochronological distribution of detrital samples from the Early-Middle Triassic and Late Triassic revealed abrupt changes,suggesting a new source supply resulting from tectonic activation in the Tianshan range.The coupling relationship between the syn-tectonic sedimentation of the Kelamayi Formation and the South Tianshan fold-thrust system provides robust evidence that the Triassic intracontinental deformation of the South Tianshan range began at approximately 226-220 Ma(during the Late Triassic)and ended at approximately 218-212 Ma.These findings provide crucial constraints for understanding the intraplate deformation in the Tianshan range during the Triassic.

关 键 词：growth strata basin-mountain coupling TRIASSIC Indosinian event Kuqa Depression South Tianshan 

分 类 号：P534.51[天文地球—古生物学与地层学] P512.2[天文地球—地质学] P597.3