【作者】 张军龙；

【导师】 丁国瑜； 任金卫；

【作者基本信息】 中国地震局地质研究所 ， 构造地质学， 2013， 博士

【摘要】 青藏高原于新生代在亚洲大陆上崛起，成为地球上最雄伟的高原。青藏高原的隆升对于季风气候的形成、过去全球气候变化有着重大的影响，是造成新生代晚期全球气候变冷、北半球冰量变化、亚洲季风形成的根本原因。于是，青藏高原变形的时代，幅度，形式、机制，以及其演化过程和环境效应的研究成为国际地学界研究的热点和争论的焦点。巴颜喀拉块体属于青藏亚板块东北部的次级块体，北邻秦祁昆块体，南接唐古拉块体，东与扬子块体接触。巴颜喀拉块体东北端（以下简称研究区）地处三大块体交接区，是青藏高原强烈隆升和向外扩展地区，也是我国大陆新构造运动和强震活动十分活跃的地区。围绕研究区内第四纪以来隆升量的研究，不仅可以认识研究区内第四纪隆升机制，促进系统认识青藏高原隆升过程及变形机制，还对研究区内的防震减灾工作具有重要的应用价值。第四纪以来，在不同的内力和外力作用下，地球表面形成多种地貌。这些地貌中包括有表征地质年龄意义的层状地貌。若在研究区域内多处地点存在一系列可以对比的不同高程或年龄的这类层状地貌序列，则可以通过对它们的研究，结合成因分析，认识区域内层状地貌反映的表面隆升量（以下简称隆升量）和隆升过程。具有地质年龄意义的层状地貌中，与隆升量相关且研究程度较高的主要有夷平面、阶地等。研究区内虽然夷平面分布相对较小、然而阶地分布较为广泛，主因是区内河流纵横，强烈切割。本文利用活动块体划分、野外地震地质调查、层状地貌对比分析和遥感解译等研究方法以及14C、ESR、OSL测年、DGPS测量、DEM空间分析等技术手段，对包括研究区内块体的划分、获取反映隆升量的方法、不同块体内各级层状地貌的沉积特征、空间参数、形成时代等的深入研究：（1）将巴颜喀拉块体东北端划分成不同的活动块体，反映各个块体之间在新生代以来具有差异活动的特征；（2）利用DGPS方法，结合高精度影像数据，提出了层状地貌空间参数的获得方法，该方法不但可以有效的节约野外现场工作时间、精度也满足要求；（3）利用（2）提出的方法，对（1）划分的各个块体内的层状地貌面进行系统的野外调查、测量、统计和对比研究，提出各个块体的标准层状剖面，进而对比分析研究区不同块体层状地貌数据反映的第四纪差异隆升量，结合测年数据和地层对比，讨论不同块体的隆升速率；（4）探讨巴颜喀拉块体向东运移对东北缘隆升过程、形变分配的约束。论文主要取得以下研究结果：（1）巴颜喀拉地块东北端块体划分根据边界活动断裂带划分活动块体的方法，利用区域大地构造环境识别出边界断裂带的出露位置；利用区域地球物理场与地壳结构分析边界断裂带深部地球物理场参数特征，进而分析其深部结构；结合地震的分布、力学特征分析断裂的活动性质和强度；结合GPS、断层活动速率等资料确定活动断裂带；并以此为依据划分出为四个一级块体和三个二级断块，四个一级块体为巴颜喀拉强隆起、龙门山断隆、四川弱隆起、秦岭断隆；二级断块为若尔盖强隆起、岷山断隆、碧口过渡区。（2）层状地貌面数据获取方法的研究近年来，随着新构造定量研究的逐步深入，要求定性或定量评价新构造时期断裂活动、褶皱活动、垂直隆升运动等等问题。为了解决这些问题，一些新的方法和手段得到了尝试和应用。论文结合实例，较系统的提出了层状地貌数据的获取方法，为研究垂直隆升提供了新的方法。提出了采用DGPS方法、DGPS方法和SPOT-5异轨立体像对综合分析方法获取层状地貌DEM数据，讨论了网格统计方法中层状地貌面在大比例DEM剖面上的形态及其统计参数意义。在均匀隆升的区域，首先用传统测量方法得到多个地点阶地序列的空间参数，统计对比分析得到该区域具有代表性的阶地序列空间参数，其次结合网格统计DEM数据得到夷平面和剥夷面、阶地的级别、分布范围和高程数据，两者相互对比、补充和验证，完善层状地貌的空间参数。存在差异运动的区域，首先划分出差异运动相对较小的次级单元，然后按上述方法对次级单元进行测量，然而进一步对区域整体活动分析。（3）各个块体隆升量的研究层状地貌面空间分布和发育特征（包括成因、类型、分布、结构、级数、后期构造变形等）是青藏高原东缘层状地貌研究过程中存在的主要问题之一。论文基于研究区内黄河支流黑河、白河，长江支流白龙江、岷江、涪江等河流阶地面的结构、类型、级数和空间分布特征的野外调查和测量，结合DEM数据，得到不同块体层状地貌的空间分布及高程/拔河参数，建立不同块体第四纪隆升量。其中若尔盖强隆起可识别出8级地貌面，夷平面指示的隆升量1400～1650m；岷山断隆可识别出12级地貌面，夷平面指示的隆升量1700～1900m；碧口过渡区可识别出11级地貌面，夷平面指示的隆升量～1350m。（4）各个块体隆升速率的讨论缺乏准确的测年数据、系统的测年剖面亦是青藏高原东缘层状地貌面研究存在的主要问题之一。通过收集各条河流流域内的构造地貌年龄数据，参考沉积特征分析和地层对比，讨论各级层状地貌的形成时代，结合（3）得到的不同块体层状地貌空间参数，建立了相应的层状地貌标尺，讨论层状地貌反映隆升速率。青藏运动以来若尔盖强隆起、岷山断隆、碧口过渡区共同开始持续均匀的强烈隆升，形成多级夷平面和阶地。三个块体之间存在差异隆升，其中岷山断隆速率最快，其次为若尔盖强隆起，碧口过渡区较弱，这种差异隆升持续至今。（5）巴颜喀拉地块向东运移对东北缘隆升过程的影响巴颜喀拉地块的北边界为东昆仑断裂带，东侧以龙门山断裂带与华南块体为界。昆仑山北侧的陇西块体及其前缘弧束区在青藏运动末期隆升运动才有所响应并逐步启动，昆黄运动末期开始加速，但仍小于若尔盖强隆起、岷山断隆、碧口过渡区三个块体的隆升速率，共和运动以后趋于一致或超过三个块体的隆升速率。龙门山东侧的四川盆地青藏运动主要表现为前陆沉积，隆升运动不明显，到共和运动以来也加入到快速隆升的运动中。以东昆仑断裂带和龙门山断裂带为界，两侧块体存在着差异隆升，其差异量可能被断层吸收，因此支持大陆逃逸模型和分块隆升模型。（6）共和运动以来，趋于一致的加速隆升过程广泛分布，并与前期有较大的差异。因此，我们推测此阶段的活动速率不能简单的反映前期活动速率，如果这一推测是正确的话，那么现今GPS反映的青藏高原的运动状态同样不能简单的延伸到青藏运动时期，甚至于共和运动时期。更多还原

【Abstract】 Since Cenozoic, the Tibetan Plateau has risen in the Asian continent and become the world’smost magnificent plateau. With a significant impact on the formation of monsoon climate and theforepassed global change, its uplift is the primary cause for global cooling, northern hemisphereice changes and Asian monsoon formation in the late Cenozoic. Thus, the deformation of TibetanPlateau has become a focused topic of international geology, with debates on the timing,magnitude, forms, mechanisms, evolution process of the deformation and environmental effects.Being a secondary terrane, the Bayan Har block belongs to the northeast of Qinghai-Tibetsubplate, adjoining the Qinling-Qilian-Kulun block in north，Tangula block in south and Yangtzeblock in east. The northeast part of the Bayan Har block (hereinafter referred to as the study area)lies in the transition zone of three large blocks, located in the area of the Tibetan Plateau whichwas intensively uplift and outward extended, as an active area of new tectonic movement andstrong earthquake regions in China. The research of uplift amount of the study area since theQuaternary time helps to understand the mechanism of uplift in Quaternary and the uplift processand deformation mechanisms in the Tibetan Plateau, playing a great role in earthquake preventionand disaster mitigation.Since Quaternary, under the action of diverse internal and external forces, a variety oflandforms have been formed on the earth’s surface. These geomorphic types include a certainsense of layered landform caused by earth crust uplift. If there are a series of layered landforms inthe study area, the research can recognize the formation process of the landscape in this area,which would reflect the amount of surface uplift (hereinafter referred to as uplift amount).Geomorphic surface is divided into many kinds, such as planation surface, terrace, etc. related totectonic setting, which are deeply researched. In long-time uplift movement areas, the river is oneof the main geologic forces transforming the surface appearance and the river terrace is the maintype of quaternary geomorphologic in mountains. There are two main rivers in the study area, theYangtze and Yellow river systems, forming multistage terraces under the effects of tectonics andclimate. These planation surfaces and terraces are the main objects of this thesis. Their spaceparameters (height), reflecting the uplift amount of the study area, are the main basic data in theresearch process.From14C, ESR, and OSL chronology of gravel beds，DGPS measurements, DEM spatialanalys is and other technical means, this work includes block division, access to uplift amountmethod, sedimentary characteristics, space parameters and formation age of the landscape:(1) Thestudy area is divided into different activity blocks, each block shows the characteristics ofactivities different from others since the Cenozoic.(2) Using DGPS methods, combined with thehigh resolution image data, a study method is proposed to acquire the layered landscape spaceparameters. This method not only effectively saves the wild field work time, but also meets theprecision requirement and increases the work efficiency.(3) The difference capacity of uplift sinceQuaternary is obtained by comparative analysis of the standard layered landscape profile indifferent blocks by the method presented in(2).Combined with dating data and strata, uplift ratesof different blocks are discussed.(4) Discuss how the eastward movement of the Bayan Har blockconstrains the uplift process and deformation distribution of the northeast edge.The major research results of this thesis are presented below.（1）Division of activity block According to the division method of the active blocks, for example, using regional tectonicenvironment to identify the boundary zone of the exposed position of faults; using the regionalgeophysical field and crust structure characteristics to analyze the deep geophysical fieldparameters of the boundary faults zone, and then its deep structure; based on the distribution,mechanic characteristics of earthquakes, the nature and intensity of the fault activity wereresearched. GPS data were combined with the fault slip rates to determine the active fault zone.Based on these results, the study area was divided into four primary blocks and three secondaryblocks. The four primary level blocks include the Bayan Har strong uplift, the Longmenshan faultuplift, Sichuan weak uplift and Qinling fault uplift; The three secondary fault blocks are the Zoigestrong uplift, and the Minshan break, the Bikou transition zone.(2) Acquisition of space parameters of layered landformIn recent years, with the development of quantitative neotectonics, qualitative orquantitative research has been required to evaluate faulting, folding activities, vertical upliftmovement in neotectonics period, and so on. In order to solve these problems, some new methodsand means are tried and applied. Based on application examples, the system of layered landformdata acquisition method is proposed. A research method was proposed to apply the DGPS method,DGPS and SPOT-5across-track stereo images to obtain layered landform data and discuss thelayered geomorphic surfaces morphology on the large scale DEM section and geomorphicsignificance in the gridding DEM profile. In uniform uplift areas inside the block, firstlytraditional measurement methods were used to get space parameters of layered landform in mainterrace and analysis made to the space parameters of the typical layered landform. Secondly, basedon DEM data, this work analyzed planation surface and denudation surface level, distributionrange and elevation data， perfects space parameters of layered landform by contrasting,complementing and validation. In evident differential movement areas, the secondary units werefirstly divided by differential movement, and then the units were measured and analyzedaccording to the methods above.（3）Uplift amount of layered landform in each block in thestudy areaDistribution and characteristics of layered landform (including the cause, type, distribution,structure, series, and the late tectonic deformation, etc.) in the Tibetan Plateau edge are one of themain problems. Based on field investigation and measurements on distribution and characteristicsof layered landform, including the area of Heihe river, Baihe river, belonging to the Yellow Rivertributaries, and Bailong river, Minjiang river, FuJiang river, belonging to the Yangtze rivertributaries, combining DEM data, space parameters of layered landform in the study area wereobtained and the uplift amount was established in different blocks since the Quaternary. The Zoigestrong uplift can be subdivided into8level layered landforms and the planation surface shows anuplift amount of1400~1650m; Minshan fault uplift12level layered landforms, with the upliftamount of1700~1900m showed by the planation surface; Bikou transition zone11level layeredlandforms, with the uplift amount of1350m.（4）Uplift rateof layered landform in each block in thestudy areaLack of accurate dating and profile of dating data is another main problem. By collectingdating data of layered landform in the study area, combined with sedimentary characteristicsanalys is and correlation of strata, the formation time of all level layered landform was discussed.Based on the space parameters of layered landform in different blocks gained in (3), relevantlayered landform scales were built for different blocks and the uplift rates were discussed. The Zoige strong uplift, Minshan fault uplift and Bikou transition zone have strongly risen since theTibetan movement. Multilevel planation surfaces and terraces have been formed. The three blocksrose at different rates, the Minshan fault block uplifts at the largest rate, followed by the Zoigestrong uplift, with Bikou transition zone the slowest. The differential uplift has continued topresent day.（5）TheBayan Har block eastward migration impact on northeast edgeThe Bayan Har block borders the eastern part of the Kunlun fault zone to the north, theLongmenshan fault zone and the South China block to the east. The west Gansu block, borderingthe Kunlun Mountains to the north, and its frontal arc beam area began to react and graduallyuplifted at the end of the Tibetan movement. The movement accelerated at the end of Kunhuangmovement, with a rate lower than that of the Zoige strong uplift, Minshan fault lung and Bikoutransition area, equal to or higher than the rate of the latter three blocks uplift after GongheMovement. During the period of Tibetan movement, the Sichuan basin, bordering Longmenshanto the west, presented foreland deposition as a result of an obvious uplift movement. SinceGonghe movement, the Sichuan basin has rapidly uplifted. Bounded by the East Kunlun fault zoneand Longmenshan fault zone, the blocks on both sides uplifted differently, with the differenceabsorbed by faults. The study indicates that the movement shows a feature of the escape modeland block uplift model.（6）Since the Gonghe movement, accelerating uplift processes converge on differentblocks that have bigger differences from early. So this study speculated that the active rate of thisphase didn’t reflect the activities of the previous rate. If this speculation is correct, today’s motionstate of the Tibetan Plateau reflected by GPS also cannot be simply extended to the Tibetanmovement period, and even the Gonghe movement period.更多还原