帕米尔弧形构造带晚第四纪以来的不对称径向逆冲:多时空尺度变形速率的启示  

Asymmetric radial thrusting of the Pamir Salient since the Late Quaternary:Implications from the spatio-temporal varations in deformation rates

作　　者：葛进 石许华 陈汉林[1,2] 林秀斌[1,2] 杨蓉[1,2] 魏晓椿 吴运鹏 李丰 程晓敢 章凤奇[1,2] 安凯旋[1,2] 徐曦[1,2,3] GE Jin;SHI Xuhua;CHEN Hanlin;LIN Xiubin;YANG Rong;WEI Xiaochun;WU Yunpeng;LI Feng;CHENG Xiaogan;ZHANG Fengqi;AN Kaixuan;XU Xi(Key Laboratory of Geoscience Big Data and Deep Resource of Zhejiang Province,School of Earth Sciences,Zhejiang University,Hangzhou 310027,Zhejiang;Research Center for Structures in Oil-and Gas-Bearing Basins,Ministry of Education,Hangzhou 310027,Zhejiang;China Aero Geophysical Survey and Remote Sensing Center for Natural Resources,China Geological Survey,Beijing 100083)

机构地区：[1]浙江省地学大数据与地球深部资源重点实验室,浙江大学地球科学学院,浙江杭州310027 [2]教育部含油气盆地构造研究中心,浙江杭州310027 [3]中国自然资源航空物探遥感中心,北京100083

出　　处：《第四纪研究》2022年第3期673-691,共19页Quaternary Sciences

基　　金：国家自然科学基金项目(批准号:41720104003、41941016、41972227、41972214、42002219和41902204);浙江省钱江人才D类计划项目(批准号:QJD1902023);浙江大学百人计划项目;中央高校基本科研业务费专项(批准号:2021XZZX005)共同资助

摘　　要：帕米尔弧形构造带作为印度-欧亚板块碰撞带变形最为强烈的地区之一,该构造带前缘发育了一系列呈弧形形态展布的活动断裂系;其向北突出的弧形形态的形成是数十年来国内外的研究热点。但关于该弧形形态的形成时间、形成机制以及帕米尔弧形构造带的演化过程仍存在很大的争议。沿弧形构造带发育的活动断裂系运动学的时空变化是揭示帕米尔弧形构造带新生代以来形成演化过程的重要窗口,但是鲜有对这些构造的多时空尺度的系统性研究。文章根据这些沿弧形构造不同的构造样式,重点总结了主要活动构造在不同时间尺度下的变形速率,并分析这些构造沿帕米尔弧形前缘的时空变化。结果表明,晚第四纪以来,帕米尔弧形构造带前缘的构造变形速率基本保持稳定,且前缘主要的逆冲和走滑运动呈现强烈的不对称特征。我们认为帕米尔弧形构造带晚第四纪以来的变形模式基本保持一致,主要表现为不对称径向逆冲的运动学模式,这一运动学模式的形成可能受控于帕米尔边界条件的差异。The Pamir Salient is one of the most tectonically active belts within/along the India-Eurasia collision zone.A series of active fault systems formed or have been reactivated along the arcuate margin of the Pamir Salient since the Cenozoic.The formation of the northward-pointing arcuate shape of the Pamir Salient has been a focus in recent decades.However,the timing,formation mechanism,and evolution process of the Pamir Salient remain controversial.The spatio-temporal variation in the kinematics of these active fault systems is key to revealing the formation and evolution of the Pamir Salient.However,few studies concentrate on the multi-timescale deformation of these structures.Based on different tectonic styles of these arcuate fault systems,we summarized the deformation rates of main active structures at different timescales(million-year,millennial and decadal)and analyzed their spatio-temporal variations.The results show that the tectonic deformation of the frontal Pamir Salient has remained relatively stable and the deformation rates of main structures along the frontal Pamir have kept relatively constant since the Late Quaternary.In the western margin of the Pamir,the sinistral-slip rate of the Darvaz fault is about 10~15 mm/a.Within the Tajik basin,the Tajik fold-and-thrust belt experienced E-W shortening at a rate of 6 mm/a.Along the northern boundary of the Pamir,the total N-S shortening rate between the Pamir and the Alai valley is about 13 mm/a and the dextral-slip rate accommodated by the Pamir frontal thrust is 5~6 mm/a.To the east,the shortening rate is approximately 6 mm/a,absorbed by the east part of the Pamir frontal thrust.In the eastern edge of the Pamir,the tectonic activity is weak and the dextral-slip rate on the Kashgar-Yecheng transfer system is 2~4 mm/a.Meanwhile,the thrust and strike-slip rates of the front show a strongly asymmetric pattern.On one hand,the shortening mainly concentrates on the western and northern margin of the Pamir,and the rate is high in the middle(about 13 mm/a)but sm

关 键 词：帕米尔弧形构造带 构造变形 多时空尺度 动力学模式 不对称径向逆冲 

分 类 号：P546[天文地球—构造地质学]