导　　师： 陈杰

学科专业： 070904

授予学位： 博士

作　　者： ;

机构地区： 中国地震局地质研究所

摘　　要： 帕米尔构造结是印度板块向欧亚大陆碰撞的两个突出支点之一，是中国大陆受板块动力作用最强烈、强震频发的地区之一，也是揭示青藏高原形成与演化历史的关键地区之一。晚新生代帕米尔构造结北部向北楔入推移了约300km，形成了一陆内深俯冲带和地震带，但对这一变形过程及方式至今未能很好的限定。沿东经76°附近横跨帕米尔-天山的最新GPS测量结果表明其现今地壳缩短速率为20-24mm//a，几乎占印度板块现今向北推挤速率/(40-50mm//a/)的一半。帕米尔已成为全球开展现今陆内再造山过程、陆内应变的空间分配和时间变化、陆内强震及其预测等大陆动力学前沿问题研究的关键地区和最理想的天然实验场。 在帕米尔西缘，构造变形持续集中在帕米尔和塔吉克盆地的边界断层、左旋走滑的达瓦孜-卡拉库尔断层/(Darvaz-Karakul Fault，简称DKF/)。与西缘不同，在帕米尔北缘的阿莱谷地，变形前缘已由帕米尔前缘逆冲推覆系/(Pamir Frontal Thrust，简称PFT/)逐步向腹陆方向后退至山前的主帕米尔断层/(Main Pamir Thrust，简称MPT/)。在帕米尔东缘，自25-20Ma以来构造变形主要通过帕米尔与塔里木盆地的边界断层喀什-叶城转换带/(Kashgar-Yecheng Transfer System，简称KYTS/)调节；至晚中新世或上新世，KYTS走滑速率由之前的~11-15mm//a减小至~1.7-5.3mm//a，帕米尔与塔里木盆地间的相对运动明显减弱，两大块体已拼接在一起并作为一整体向北运动。区域构造格局的变化，必然导致应变的重新分配。那么最新构造变形带位于何处，具有怎样的变形特征，缩短速率如何？GPS观测的该最新构造变形带现今地壳缩短速率约为6-9mm//a，这与第四纪时期的地质变形速率是否一致？在时间和空间上应变是如何在塔里木与帕米尔两个相互作用的地体间传递、分配的？是一个还是多个构造� The Pamir is located in the northwestern corner of the Indo-Asian collision zone. During late-Cenozoic times,the northern margin of the Pamir has indented northward~300km, accommodated by south-dipping intracontinentalsubduction along the Main Pamir Thrust /(MPT/) and coupled the strike-slip on the western and eastern margins.Along the western margin, deformation has been persistently concentrated on the Pamir-Tadjik boundary faultDarvaz-Karakul Fault /(DKF/). In the Kyrgyz Alai Valley along the northern margin, the Pamir Frontal Thrust /(PFT/)has become inactive and deformation has stepped hindwards to the MPT. Along the estern margin, deformation hadbeen concentrated on the Pamir-Tarim boundary fault-Kashgar-Yecheng Transfer System /(KYTS/) since acitivtyinitiation /(~25-20Ma/); by late Miocene-Pliocene, strike-slip along the KYTS decreased dramatically from~11-15mm//a to~1.7-5.3mm//a, indicating the Pamir jointing together with the Tarim and subsequent northward motiontoward the Tian Shan. In response to tectonic setting transformation, regional straining was re-distributed. A series ofissues need to be addressed, such as the location, deformation characteristics, shortening rate accommodated of thedeformation frontier, the recent straining sptial distribution along eastern and northestern margin of the Pamir, thedifferences of straining distribution among the eastern, westen and northern margin, as well as the differences andsimilarities between the Tian Shan and the Pamir orogenic process. Keeping this motivation, this work investigatedactive deformation along northeastern margin of the Pamir. From this study, the following insights are attained: 1/) Spatial distribution of active structures along the NE margin of the Pamir. Along the NE margin of the Pamir, late-Cenozoic geologic deformation is concentrated on the MPT along thePamir’s mountain front, on the PFT along the deformation leading edge, and on the piggyback basin between them.The MPT, separating domains with contrasting geology and geomo

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