四川马尔康6.0级震群区流域地貌特征与控制因素研究

2022年6月10日四川马尔康6.0级震群地震发生在青藏高原东缘,位于强烈隆升的龙门山及其西缘高原腹地过渡地带,断裂构造复杂,水系发育,小震与中强地震活动频发。基于90 m×90 m空间分辨率的SRTM3数据,利用数字地貌分析方法提取了马尔康6.0级震群所在的脚木足河流域坡度、起伏度、面积-高程积分和河道陡峭指数等地貌参数,结合降水和岩性数据进行综合分析。研究结果表明,脚木足河流域坡度、起伏度、面积-高程积分和河道陡峭指数整体表现出西北低、东南高的特征。构造活动是导致区域地貌参数呈现差异性的主要原因,地貌参数高值主要分布于龙日坝断裂两侧,沿松岗断裂两侧展布,龙日坝断裂东侧是构造变形与差异性隆升强烈的龙门山地区;龙日坝断裂西侧是多条断裂交汇的构造复杂区,中强地震活跃,地貌破坏与重塑作用相对强烈,这可能是地貌参数高值的主要原因。     

格仁错断裂带流域地貌特征及其构造指示意义

依据谷歌地球提供的影像(Landsat和GeoEye)和野外工作,在ArcGIS平台上利用数字高程模型(ASTER GDEM数据)提取了格仁错断裂带153个亚流域盆地的基本参数,作了面积-高程积分。统计结果显示,南北2盘流域盆地的规模(面积、河网分级)差异显著,南盘流域盆地起伏、坡度、面积-高程积分(HI)值均略大于北盘,积分曲线总体呈"南凸北凹"的形态特征;在断裂走向上,盆地起伏、平均坡度、HI值皆呈"东南高、西北低"的趋势,积分曲线由西向东具有变凸的态势。通过分析流域岩性与降雨条件,发现它们对以上地貌参数的影响有限。因此,流域盆地差异地貌特征反映并验证了格仁错断裂晚新生代南盘相对于北盘抬升,并且其南侧申扎-定结裂谷可能强化了该差异抬升运动。同时,可能指示冈底斯-念青唐古拉山晚新生代早期隆升为流域盆地提供了向N掀斜的先存地貌面,后期该山体和申扎-定结裂谷的快速隆升进一步促成南北2盘流域不对称的发育。     

青海达日断裂中段构造活动与地貌发育的响应关系探讨

青海达日地区发育了多条晚第四纪活动断裂带,以NW—NNW向和近SN向为主。通过航卫片解译和野外实地调查发现,达日断裂中段晚第四纪新活动性尤为显著,其性质以左旋走滑为主,至今部分地段仍保存了清晰的1947年达日7级地震地表破裂带,其破裂样式具有分段性和多样性,反映了局部构造应力的差异。达日地区作为典型的活动构造区,是研究新构造运动与地貌响应的理想场所。因此,文中采用ASTER GDEM V2数据提取了该地区的水系网络和亚流域盆地参数,计算了亚流域盆地面积-高程积分曲线和积分值(HI值),讨论了其构造活动性及地貌响应的关系。区内黄河的6个亚流域盆地的面积-高程积分曲线形态分析结果表明,这6个亚流域盆地均处于地貌演化阶段的"壮年期",其演化过程表现出很好的同步性,反映了区域性构造隆升或沉降作用的总体结果。而且,区内亚流域盆地的面积-高程积分值(HI值)分布特征表明,HI低值分布与第四纪断陷盆地和河谷盆地范围相一致,反映了局部不同构造沉降和侵蚀作用的结果;HI高值则主要出现在达日地震地表破裂带由NWW向NW转向的部位,以及早侏罗世与晚三叠世花岗闪长岩体分布的地方,也很好地反映了局部构造作用的变化和地层岩性的差异。     

祁连山西段疏勒河流域地貌特征及其构造意义

疏勒河流域盆地位于祁连山西段,跨越了该区多条不同方向和不同性质的活动断裂带,其所呈现的地貌特征反映了该区最新构造活动的信息。文中基于GIS空间分析技术,利用SRTM-3数字高程模型(DEM)数据,系统提取了疏勒河流域及其4个亚流域盆地的面积-高程积分曲线、疏勒河水系的Hack剖面以及河流坡降指标(SL),并对整个流域地形做了坡谱分析,获得了疏勒河流域的地貌特征。研究表明,疏勒河的流域地貌发育受到该区的阿尔金断裂、昌马断裂、托勒南山断裂以及疏勒南山断裂等强烈构造活动和区域岩性差异的影响,坡度以0°~35°的区段为主;整个流域盆地处于河流发育的"壮年期";构造活动是造成河流纵剖面发生改变的最主要因素,局部河段同时还受到岩性因素的控制和影响。这表明在活跃的造山带内部,河流地貌的发育过程中,活动断裂的构造作用是重要的控制因素。     

六盘山断裂带构造活动特征及流域盆地地貌响应

通过航卫片解译和野外实地调查,对六盘山断裂带新活动特征开展详细研究。调查发现六盘山东麓断裂为一条全新世活动的逆左旋走滑断裂,而六盘山西麓断裂为晚更新世活动的挤压逆冲断裂,二者的构造活动控制和影响了本区的地貌发育和地震活动。同时利用SRTM数据提取六盘山东西两侧泾河和水洛河上游流域盆地水系,得到流域盆地面积-高程积分值(HI值)分布图,探讨本区活动构造和地貌的响应关系。分析结果表明,在相同的岩性条件下六盘山东侧的HI值要低于西侧,反映了活动断裂对本地区地貌演化特征的不同影响。上述地貌分析研究为认识和理解六盘山地区地貌演化以及控制因素提供了基础数据和思路。     

涪江流域河流地貌特征对虎牙断裂带活动性的响应

青藏高原东缘岷山东边界的虎牙断裂带强震频发,但因第四系保留有限,目前对于该断裂的活动性仍认识不清。而基岩山区河流地貌与活动构造关系研究发现,河流地貌特征能够很好地记录构造活动信息。虎牙断裂带横跨涪江流域,这为通过河流地貌研究虎牙断裂的活动特征提供了条件。文中选择涪江流域SRTM 30m精度数字高程模型(DEM)数据,利用GIS技术提取了涪江流域坡度(slope)、局部起伏度(local relief)、标准化陡峭指数(ksn)、面积-高程积分值(HI)等地貌指数,并对跨虎牙断裂带小流域盆地的平均陡峭指数(ks)和面积-高程积分值进行对比,结合野外调查、岩性、降水与现代侵蚀速率等特征,分析讨论了涪江流域地貌特征与虎牙断裂带活动特征的关系。研究表明:1)涪江流域基本处于稳态状况,区内仅有跨雪山断裂带的河道剖面显示明显的裂点,其余跨断裂河道剖面无明显裂点存在;2)虎牙断裂带两侧地貌指数差异明显,整体上表现为西高东低,这应与虎牙断裂的逆断活动有关;3)断裂两侧的小流域地貌指数差异分析表明,沿虎牙断裂带自北向南抬升作用逐渐增强,反映了虎牙断裂带北段以走滑为主,南段以逆断为主。该研究有助于提高对青藏高原东缘隆升变形机制的理解。     

浅层地震勘探与联合钻孔探测揭示丽江-小金河断裂隐伏段复杂花状构造特征

丽江-小金河断裂是川滇菱形块体内部重要的边界断裂,前人根据其断错地貌特征确定其为左旋走滑断层,并认为其左旋断错了SN向的丽江盆地。本文对丽江-小金河断裂丽江盆地隐伏段开展了浅层地震勘探与钻孔探测,通过地层岩性分析建立跨断层的钻孔联合剖面,揭示丽江-小金河断裂斜穿了丽江盆地,隐伏段整体形式为不对称正花状构造,表现为断展褶皱和逆冲断层,但主断层顶部表现为局部拉张,断错了晚第四纪地层。     

地貌参数指示的临潭-宕昌断裂带最新构造隆升差异与地震活动

2013年7月22日,甘肃岷县漳县MS6.6地震发生在青藏高原东北缘的临潭-宕昌断裂带上。为了研究该断裂的最新构造隆升的差异性,基于ASTER GDEM数字高程模型数据提取了流域盆地及水系,并以此为基础,计算了面积高程积分及河道坡度指数。2个地貌参数的分析结果表明,临潭-宕昌断裂不同部位的最新隆升呈现不均匀性。其中,断裂的最新逆冲活动在临潭以西及以岷县附近明显强于其他各段。上述地貌参数所指示的断裂抬升强度还与历史及现今地震发震位置较好地匹配,体现了定量化地貌分析对断裂活动强弱的指示作用。临潭-宕昌断裂受区域NE-SW向挤压构造应力作用影响,其活动的差异可能与晚第四纪以来巴颜喀拉块体NE向扩展背景下的局部应力集中有关。     

基于GIS平台的石羊河流域地貌演化及构造活动性研究

基于ARCGIS 10.2平台,利用GDEM-30 m数据对石羊河流域进行水文分析,提取出了石羊河流域的流域范围,在此基础上通过研究区子流域的划分,把石羊河流域上游的8个子流域作为研究重点进行讨论。通过提取石羊河流域的地貌参数,包括盆地形状指数(BS)、盆地不对称度(AF)以及计算子流域高程—面积积分值(Hi)和水系分支比(Rb),并与前人活动构造研究成果对比。认为,石羊河流域盆地较为规则,且流域构造活动性相对较弱;主流域两侧掀斜程度低,且流域东侧稍弱于西侧;而流域高程—面积积分值从东往西呈逐渐增大的趋势,河流分支比则呈现出与之相反的变化趋势,综合反映了石羊河流域构造活动性不强,并且东部构造活动性弱于西部。     

墨脱断裂地貌特征及其构造意义

墨脱断裂展布于南迦巴瓦构造结的东侧,晚第四纪以来活动强烈,断裂水平运动表现为左旋走滑。为了进一步研究墨脱断裂倾向滑动特征及断裂活动性差异,文章基于DEM数据提取了4对横跨断裂矩形区域内的高程数据,计算获得沿断裂发育的31个流域盆地的面积高程积分值。研究表明,墨脱断裂两侧在同一高度出现对称的4组台地面,且从低到相邻的两级台面的高度差没有出现逐步增大的趋势,表明断裂没有表现出明显的倾向滑动;沿断裂分布的汇水盆地具有较大的面积高程积分值（0.42~0.60之间）,反映出墨脱断裂所在区域目前总体表现为强烈的构造隆升;根据汇水盆地面积高程积分值的空间分布特征,区域地壳隆升强度沿墨脱断裂由南至北具有逐渐减弱的趋势,结合断裂地貌形态,认为在强隆升区面积高程积分值对断裂活动性具有一定的指示意义。     

龙门山中北段流域地貌特征及其构造意义

龙门山中北段位于青藏高原东缘,该区作为高原向东扩展的前缘部位,其地形与河流水系的演化记录了高原隆升与挤压扩展及其气候环境效应的各种信息。龙门山中北段构造活动有明显差异,从中段逆冲为主转化为北段的走滑为主,本文采用定量化地貌参数从构造地貌的角度揭示了区域构造活动的差异。龙门山中北段地貌因子（坡度、地形起伏度和条带状剖面）的阶梯状分布特点,显示了高原扩展的逆冲推覆特征,在中央断裂处构造抬升作用最强,同时显示出了南北向构造活动减弱的趋势,由中段的逆冲转换为北段逆冲兼走滑的形式。北川-映秀断裂两侧流域的HI值也显示了断裂上盘高、下盘低、沿走向减弱的趋势。综合分析认为,本区构造活动是地貌演化的主控因素,龙门山中北段地形存在差异,北川-映秀断裂两侧的小流域地貌指数分析显示,构造抬升活动自南向北减弱,中段以逆冲为主,北段为逆冲兼走滑。     

THE RESPONSE OF FLUVIAL GEOMORPHOLOGIC CHARACTERISTICS OF THE FUJIANG DRAINGE BASIN TO ACTIVITY OF THE HUYA FAULT ZONE

The Huya Fault, located in the steep topographic boundary of the Minshan Mountains in the eastern margin of the Tibetan plateau, has documented many major earthquakes such as the 1630(M=6 3/4), 1973 Huanglong(M_S=6.5) and the 1976 Songpan-Pingwu earthquake swarm(M_S=7.2, 6.7, 7.2). While its activity remains unclear because of lacking Quaternary sediments. In the past few decades, there have been significant advances in understanding the relationship between bedrock channel landscapes and active tectonics, indicating that the bedrock fluvial features can well record the tectonic activity. Many studies reveal that tectonism is the primary factor of landscape evolution in tectonically active regions, and the erosional landscapes can be used to reveal tectonic signals on timescales of 10³~10⁶ years. The Huya Fault crosses the Fujiang drainage basin, making it suitable for the study of bedrock rivers and tectonic uplift in the eastern margin of Minshan. In this study, we calculate the geomorphologic indeices(hillslope, local relief, normalized steepness indices and hypsometric integral) on the basis of the digital elevation model(DEM) SRTM-1. For better understanding the tectonic activity along this fault, we derive some small catchments on the two sides of the Huya fault to analyze the differences of average steepness indices and hypsometric integral. Combining with field observations, lithology, precipitation and modern erosion rates, this study suggests that tectonic activity is the controlling factor of geomorphology in the eastern margin of the Minshan Mountains. We use focal mechanism solutions, GPS data and geomorphic evidence to explore the relationship between the geomorphologic indices of the Fujiang drainage and activity characteristics of the Huya fault. Our results suggest that:(1) The Fujiang drainage basin is in a steady state. The characteristics of the knickpoints indicate that they are mainly controlled by the locally resistant substrate. (2) The suggested value of the geomorphologic index on the west side of the Huya fault is generally larger than on the east side, showing differential tectonic uplift rates across the fault. (3) The difference of the geomorphologic index of the small catchments on both sides of the Huya fault is gradually increasing from north to south along this fault, in accordance with that the north and south segments of the Huya fault are dominated by strike-and reverse-slip, respectively.     

长白山天池火山主断裂活动与热液蚀变带

在野外考察中发现，天池破火山口内壁同一层位不同段的近水平向红褐色、砖红色热液蚀变带顶界面有明显高差热液蚀变顶界面，北段(靠近天文峰)比南段(朝鲜境内靠近将军峰)高出约110m。热液蚀变带顶界面可作为判断构造运动的标志面。北段与南段顶界面的高差，反映了自热液蚀变以来，天池火山北东向主断裂六道沟-天池-甑峰山断裂北西盘的抬升幅度大于南东盘，这可能是天池北西部较南东部地形坡度更陡、水系更发育的内在原因。北西向主断裂——白山镇-天池-金策断裂北东盘的抬升幅度大于南西盘。由热液蚀变和古风化壳特征观察到的北东向主断裂的近期垂向活动速率大于北西向主断裂的活动速率。这两条在天池交叉的主断裂将天池火山切割成4个块体，它们的抬升幅度从大到小依次为北、西、东、南块体。北块体抬升幅度最大，这与深地震测深、大地电磁探测等得出的天池北部岩浆囊较浅的结果有较好的对应关系和一定的成因联系。     

GEOMORPHOLOGY OF THE GYARING CO FAULT ZONAL DRAINAGE SYSTEM AND ITS STRUCTURAL IMPLICATIONS

Strike-slip faults and normal faults are dominant active tectonics in the interior of Tibetan plateau and control a series of basins and lakes showing extension since the Late Cenozoic, by contrast with the thrust faulting along the orogenic belts bordering the plateau. The late Neotectonic movement of those faults is key information to understand the deformation mechanism for Tibetan plateau. The Gyaring Co Fault is a major active right-lateral strike-slip fault striking~300° for a distance of~240km in central Tibet, in south of Bangong-Nujiang suture zone. The Gyaring Co Fault merges with the north-trending Xainza-Dinggye rift near the southern shore of Gyaring Co. From NW to SE, Dongguo Co, Gemang Co-Zhangnai Co, Zigui Co-Gyaring Co form the Gyaring Co fault zonal drainage basin. Some scholars have noticed that the formation of lakes and basins may be related to strike-slip faults and rift, but there is no analysis on the Gyaring Co fault zonal drainage basin and its response to regional tectonics. In recent years, a variety of quantitative geomorphic parameters have been widely used in the neotectonic systems to analyze the characteristics of the basin and its response mechanism to the tectonic movement. In this paper, we applied ASTER GDEM data on the ArcGIS platform, extracted the Gyaring Co fault zonal drainage basin based on Google Earth images (Landsat and GeoEye) and field work. We acquired basic geomorphic parameters of 153 sub-basin (such as grade, relief, average slope, area) and Hypsometric Index (HI) value and curve. Statistical results have indicated significant differences in scale(area and river network grade)in north and south sides of the fault. Southern drainage basins' relief, slope, HI value are higher than the northern basins, and the overall shape of hypsometric curve of northern basins are convex compared with southern concavity. Along the strike of the Gyaring Co Fault, average slope, and HI value are showing generally increasing trending and hypsometric curve become convex from west to east. By comparing and analyzing the lithology and rainfall conditions, we found that they have little influence on the basic parameters and HI value of drainage basins. Therefore, the changes of basin topographic differences between northern and southern side of fault and profile reveal the Gyaring Co Fault has experienced differential uplift since the late Cenozoic, southern side has greater uplift compared to the north side, and the uplift increased from NW to SE, thus indicate that normal faulting of the Gyaring Co Fault may enhanced by the Xainza-Dinggye rift. The early uplift of the Gangdise-Nyainqentanglha Mountain in late Cenozoic might provide northward inclined pre-existing geomorphic surfaces and the later further rapid uplift on the Gangdise-Nyaingentanglha Mountain and Xainza-Dinggye rift might contribute to the asymmetrical development of the Gyaring Co fault zonal drainage basin.     

中国现今地壳运动GPS速度场的连续变形分析

利用中国大陆以及蒙古、 缅甸、 印度、 尼泊尔和喜马拉雅等周边地区多年的GPS观测资料, 基于连续介质假设, 采用双三次样条函数模拟方法, 给出中国大陆整体水平位移速度, 拟合精度优于3 mm/a, 获得了中国大陆的水平应变率场, 并分析了中国大陆现今构造变形、 水平应变率场的空间分布特征. 结果表明: 对大范围、 密集的GPS速度场的连续变形分析, 既能揭示中国大陆现今构造变形的总体特征, 又能显示局部地区现今的构造活动特征. 总体上, 中国大陆构造的水平变形强度和变形速度在南北地震带产生突变, 呈西强东弱、 南强北弱态势. 而昆仑山地块中部、 鲜水河断裂带和云南中部地区, 其应变速率最大, 速度变化最快; 阿尔金断裂带现今处于其构造活动的平静期, 中天山东部地区具有拉张环境.      

滇西北区断层分数维几何学的研究

本文应用分数维几何学的方法,对滇西北区断裂系进行解析并确立了各断裂系的地位;从该区各典型子区活动断裂与水系的几何学分析和对比,探讨了二者的分布特征及其相关性     

A NEW DISCOVERY OF ACTIVITY OF FUSHAN SECTION OF THE TAN-LU FAULT ZONE IN THE LATE QUATERNARY

The east branch fault of Tan-Lu fault zone extends from Fengshan Town of Sihong County on the north shore of the Huaihe River in Jiangsu Province, into Fushan Town of Mingguang City on the south shore of Huaihe River in Anhui Province. The landform changes from Subei plain on the north of Huaihe River to Zhangbaling uplift area on the south of Huaihe River. The terrain rises gradually with larger relief amplitude. The Fushan section of the Tan-Lu fault zone is located in Ziyang to Fushan area of Mingguang City. The fault is shown in the satellite image as a clear linear image, and the fault extends along the east side of a NNE-trending hillock. In this section the Quaternary strata are unevenly distributed, which causes some difficulties in the study of recent fault activity.In recent years, the author has found that the fault of the Fushan section of the Tan-Lu fault zone on the south of the Huaihe River still has a certain control effect on the landform and the Quaternary strata. Based on satellite imagery and geological data, we select the appropriate location in the Fushan section to excavate the Santang trench Tc1 and Fushannan trench Tc2, and clean up the Fushannan profile Pm, which reveals rich phenomena of recent fault activity. Santang trench reveals three faults, and the faulting phenomenon is obvious. One of the faults shows the characteristic of right-lateral strike-slip normal faulting; Fushannan profile reveals one fault, with the same faulting behavior of right-lateral strike-slip normal fault. Comprehensive stratigraphic sample dating results indicate that the fault dislocated the middle Pleistocene strata, late Quaternary strata and early Holocene strata. All our work shows that the fault of Fushan section has intensive activity since late Pleistocene, and the latest active age can reach early Holocene. The latest earthquake occurred at(10.6±0.8)~(7.6±0.5)ka BP. The faults exposed by trenches and profiles show the characteristics of right-lateral strike-slip normal faulting, which reflects the complexity of the tectonic stress field in the area where the fault locates.     

河西走廊西端花海断裂晚第四纪活动特征

花海断裂是位于河西走廊西端阿尔金断裂系北侧花海盆地内的一条活动断裂,对该断裂活动性的认识不仅有助于评估该区的地震危险性,而且对深入理解青藏高原向北扩展过程中块体相互作用具有重要的科学意义。遥感解译与地震地质调查表明,花海断裂仅局限于花海盆地内,长度约25 km。断裂走向NNW,南端起自花海镇以南,向北经小泉、大泉、双泉子后穿过山水河,向北逐渐消失在北山山前大型冲积扇前。地貌上,花海断裂南部表现为线性延伸的断层陡坎,北段构成了风成砂丘与冲洪积扇的界线。在断裂北段跨断层陡坎进行了探槽开挖,探槽揭露和光释光年代学测试结果表明,该断裂最新一次古地震事件的时间距今约5万年,全新世以来没有明显的活动迹象,为晚更新世活动断裂。结合陡坎位错分析,花海断裂晚第四纪以来垂直滑动速率小于0.03 mm/a。区域大地构造动力学背景分析表明,花海断裂是在青藏高原向北扩展作用下盆地内形成的次一级活动断裂,是高原外围块体对青藏高原向外扩展的响应。     

EVIDENCES OF THE LATE QUATERNARY ACTIVITY OF THE ANGREN SEGMENT OF THE YARLUNG TSANGPO FAULT ZONE

The Yarlung Tsangbo fault zone, one of the most important geological interfaces in the Yarlung Tsangbo suture zone which is a huge geotectonic boundary with nearly east-west-trending in southern Tibet Plateau, has undergone a long-term tectonic evolution. Studying this fault zone can help us understand the development and evolution history of the suture zone and the tectonic mechanism of subduction-collision about the Tibet Plateau, so it has always been a hot topic in the field of geology. Most of existing data suggest that the current tectonic activity in southern Tibet is given priority to the rift system with nearly north-south-trending, and the Yarlung Tsangbo fault zone with nearly east-west-trending has relatively weaker activity since late Quaternary. There are only some evidences of Holocene activity found in the Lulang town section near eastern Himalayan syntaxis, and there are few reports about the reliable geological evidences of late Quaternary activity of the section on the west of Milin County of the fault zone. Based on image interpretation, field investigation and chronological method, we found several fault profiles along the Yarlung Tsangbo fault zone near the Angren Lake in this study. These profiles reveal that loose fault gouge has been developed on the fault plane which nearly extends to the surface and offsets the loess sediments and its overlying alluvial-proluvial gravels. The loess is characterized by coarser grains, higher content of fine sand and tiny small gravels. The results of the two OSL dating samples collected in the loess are(94.68±6.51)ka and(103.84±5.14)ka respectively, showing that the loess revealed at the Angren site should be the middle-late Pleistocene sand loess distributed on the high-terraces along the Yarlung Tsangpo River. Consequently, the Angren segment of the Yarlung Tsangpo fault zone is active since the late Quaternary. In addition, synchronous left-lateral offsets of a series of small gullies and beheaded gullies can be seen near the profiles along the fault, which are the supporting evidence for the late Quaternary activity of the fault. However, the segment with obvious geomorphology remains is relatively short, and no evidence of late Quaternary activity have been found in other sections on the west of Milin County of the Yarlung Tsangpo fault zone. Existing data show that, in the southern Tibet, a series of near NS-trending rift systems are strongly active since the late Quaternary, cutting almost all of the near east-west-trending tectonic belts including the Yarlung Tsangpo fault zone. In addition, majority of the earthquakes occurring in southern Tibet are related to the NS-trending rift systems. Tectonic images show that the Angren segment locates between the Shenzha-Dingjie rift and the Dangreyong Lake-Gu Lake rift. These two adjacent rifts are special in the rift system in southern Tibet:Firstly, the two rifts are located in the conversion position of the trend of the whole rift system; Secondly, the size of the two rifts varies significantly between the north side and the south side of the Yarlung Tsangbo fault zone. Thirdly, the Shenzha-Dingjie rift seems to be of right-lateral bending, while the Dangreyong Lake-Gu Lake rift shows left-lateral bending. These characteristics may lead to the fact that the amount of absorption and accommodation of the rift activities in the north side of the Yarlung Tsangbo fault zone is larger than that in the south side during the migration of the plateau materials, leading to the differential movement of the block between the two sides of the fault zone. Therefore, the Yarlung Tsangbo fault zone possesses the accommodating tectonic activity, of course, the intensity of this accommodating activity is limited and relatively weaker, which may be the reason why it is difficult to find large-scale tectonic remains characterizing the late Quaternary activity along the fault zone. The scale of the rift system in southern Tibet is systematically different between the two sides of the Yarlung Tsangbo fault zone, so it cannot be ruled out that there are also weak activities similar to the Angren segment in other sections of the fault zone.