海原走滑断裂带及其尾端挤压构造

研究了青藏高原东北部地区海原活动断裂带的几何学、运动学和动力学特征、左旋位移总量及全新世滑动速率,对海原走滑断裂带东南端发育的尾端挤压区的构造特征及地壳缩短量进行了研究,分析了走滑断裂带的走滑量与端部挤压区地壳缩短量之间的转换平衡关系     

活动断裂带上的粘滑和蠕滑标志及其研究意义

简要概述活动断裂带上粘滑与蠕滑标志研究进展,着重探讨活动断裂带中赋存的显微粘滑与蠕滑标志,立足于天然断错产物的微观观测与岩石实验成果相结合的分析,初步提出一些对比性较好的的活动方式标志,以此为活动断裂带粘滑和蠕滑段的划分提供微观依据,并就微观粘、蠕滑标志在断裂分段中的应用、定向微观活动方式标志的运动学和动力学意义以及利用其确定古地震期次和重复间隔等作了有益的讨论.     

青藏高原中部NE向其香错断裂全新世左旋走滑速率及其构造意义

青藏高原中部NE向断裂滑动习性的研究缺失制约着我们对青藏高原中部变形模型的理解。文中选取In SAR结果为右旋走滑的NE向其香错断裂为研究对象,通过Google Earth卫星影像解译,选取了1个典型断错地貌点,利用无人机航拍结合RTK-GPS地面控制点测量获取了高精度、高分辨率的DEM,利用La Di Caoz_v2. 1软件自动提取的T2地貌面上最大冲沟的水平左旋位错为（21. 3±7. 1） m,跨断层陡坎剖面揭示了T2地貌面的垂直位错量为（0. 9±0. 1） m。在T2地貌面上采集的2个U系测年样品的年龄分别为（4. 98±0. 17） ka和（5. 98±0. 07） ka。上述数据约束了其香错断裂全新世左旋走滑速率约为（3. 56±1. 19） mm/a,垂向滑动速率约为（0. 15±0. 02） mm/a。其香错断裂左旋走滑带有倾向分量的运动学特征与青藏高原中部地壳物质向E运移的特征相符合,其运动速率与其共轭断裂（格仁错断裂）基本一致,显示出青藏高原中部变形样式符合共轭走滑断裂模式。     

红河-金沙江走滑断裂带的岩浆活动特征与深部作用过程初探

出露于红河-金沙江走滑断裂带及其两侧的碱性和偏碱性岩,主要为钾玄岩系列的火成岩,时代为第三纪其地球化学特征具俯冲带钙碱性系列与板内碱性系列的过渡性质,岩浆起源于软流圈的顶部软流圈物质的横波速度和厚度可能是岩浆活动出现与否的地球物理标志,出现火山活动地区的软流留物质的横波速度较低红河-金沙江走滑断裂带慢源岩浆活动的形成与印度板块向北挤压引起的岩石图下软流圈物质的运动有直接关系,在南北向的会聚过程中软流层物质可能扮演了重要的角色,火成岩的性质与其所处的特殊构造环境有关     

西秦岭北缘断裂和海原断裂的走滑转换变形及其与陇山地块的相…

根据对调查资料，航卫片判译和已有文献的综合分析，研究了西秦岭北缘断裂东段和海原断裂南段的走滑转换，变形及其与陇山地块的相互作用。ＸＱＬＦ以几何学结构复杂和多期活动为特征，主带各段呈左阶斜列。ＨＹＦ南段的陇县－宝鸡断裂由４条断层组成７０ｋｍ的宽带，中更新世以来表现为左旋增滑运动。     

内蒙大青山山前活动断裂带西端左旋走滑现象

位于大青山山前断裂西端约１０ｋｍ的地段,１８条冲沟不同程度地发生了左旋扭曲,扭曲量２０～３００ｍ不等。冲工度与左旋扭曲量显示了较好的正比关系。从山前台地与冲沟的切割关系可以看到,这些上游长度１～５ｋｍ及小于１ｋｍ的冲沟形成在晚更新世末期及全新世以后,同时冲沟沟口河流冲洪积相砂砾石层直接与山边黄色亚砂土断层接触,断层下降盘地层年龄早于断层上升盘的地层年龄,显示了断层的走滑活动,由断错的地层年代估算,大青山山前活动断裂西端全新世左旋走滑速率达到５ｍｍ／ａ。此外,本文还讨论了了大青山山前活动断裂的演化机制。     

藏北改则县别若则错活动断裂的发现及其地质意义

由于调查研究资料有限,目前对藏北高原内部近EW向的伸展变形样式和具体调节机制一直存在诸多争议。最新开展的地表调查在藏北高原西部的别若则错新发现了1条长约20km、走向近NNW的走滑断裂。该断裂表现出断塞塘、水系错动及断层崖等典型的走滑断裂变形标志。水系错动及构造地貌显示,别若则错断裂是以右旋走滑运动为主、兼具明显正断分量的张扭性断层,是高原内部近EW向伸展变形的产物。通过与羌塘古大湖进行对比分析,认为该断裂错断的最新地貌体是晚更新世的冲洪积扇,未错断全新世扇体,且断崖坡角已显著变缓,表明其最新活动时间可能为晚更新世。综合分析地表调查和遥感影像的错断位移恢复结果,发现最新一次断裂活动的最大右旋走滑位移约2～3m。晚更新世早—中期冲洪积扇体的累积最大右旋走滑位移约44m,垂直错动约2m,由此推测该断裂晚第四纪以来走滑速率约1mm/a,显示弱走滑变形特征。别若则错断裂近NNW的走向与印度和欧亚板块碰撞的主压应力轴(σ1)的夹角约30°,而已发现的区域性共轭走滑断裂与σ1呈约60°～75°的较大夹角,两者显著不同,表明藏北地区共轭走滑断裂带的组合方式可能存在不同的样式:一种是钝角,可能与拉萨和羌塘地体内的剪切作用或块体挤出有关;另一种是锐角,可能代表着新生破裂特征,推测其可能与高原内部近SN向正断层的N向的延伸有关,其成因机制仍需进一步研究。     

走滑断裂带中挤压阶区内部剪切构造初探

野外地质调查和航片立体镜下解译发现,小江断裂带北段蒙姑和东支大营盘两个挤压阶区内部发育有剪切构造,它们在地表主要表现为断裂槽地、断层陡坎、地裂缝等。挤压阶区内部剪切构造和拉张阶区内部剪切构造一样,是阶区形成后,随着走滑断裂的进一步活动而形成的新生性构造     

GEOLOGICAL AND GEOMORPHIC EVIDENCE FOR DEXTRAL STRIKE SLIP OF THE HELAN SHAN WEST-PIEDMONT FAULT AND ITS TECTONIC IMPLICATIONS

The horizontal movement of the Helan Shan west-piedmont fault is important to determination of the present-day boundary between the Alashan and North China blocks as well as to the exploration of the extent of the northeastward expansion of the Tibetan plateau. Field geological surveys found that this fault cuts the west wing of the Neogene anticline, which right-laterally offset the geological boundary between Ganhegou and Qingshuiying Formations with displacement over 800m. The secondary tensional joints (fissures)intersected with the main faults developed on the Quaternary flood high platform near the fault, of which the acute angles indicate its dextral strike slip. The normal faults developed at the southern end of the Helan Shan west-piedmont fault show that the west wall of this fault moves northward, and the tensional adjustment zone formed at the end of the strike slip fault, which reflects that the horizontal movement of the main fault is dextral strike slip. The dextral dislocation occurred in the gully across the fault during different periods. Therefore, the Helan Shan west-piedmont fault is a dextral strike slip fault rather than a sinistral strike slip fault as previous work suggested. The relationship between the faulting and deformation of Cenozoic strata demonstrates that there were two stages of tectonic deformation near the Helan Shan west-piedmont fault since the late Cenozoic, namely early folding and late faulting. These two tectonic deformations are the result of the northeastward thrust on the Alashan block by the Tibet Plateau. The influence range of Tibetan plateau expansion has arrived in the Helan Shan west-piedmont area in the late Pliocene leading to the dextral strike slip of this fault as well as formation of the current boundary between the Alashan and North China blocks, which is also the youngest front of the Tibetan plateau.     

上拉秀一小苏莽断裂带新活动特征与地震关系探讨

青海省玉树县上拉秀乡至小苏莽乡曾发生过多次中强地震,由于震级不高、危害不大及条件所限,未能进行详细的野外地质调查,只是初步判断上拉秀-小苏莽断裂带为全新世活动断裂带,为多次中强地震的发震构造。     

现代构造应力场对区域断裂类型及其活动方式的影响

通过对四川地区近百次地震震源机制结果的分析,研究了现代构造应力场对区域断裂类型及其活动方式的作用和影响。结果表明,四川地区强震的发震机制与区域断裂类型及其活动方式有着十分密切的联系。     

措勤地区活动断层构造特征

青藏高原自然环境恶劣,地震台网分布稀疏,基于ETM数据,对措勤地区活动断层构造进行了解泽,并建立了活动断层构造框架。通过分析活动断层与地震活动性的关系,指出措勤地区活动断层的活动性对青藏高原地震研究有着重要的意义。     

利用滑动速率、古地震资料估算走滑断裂的粘滑及蠕滑量的方法

断层走滑包括粘滑和蠕滑,前者是伴有强震发生的快速运动,后者则是一种缓慢的无震稳滑运动。这２ 种运动常随时间交替出现,共同构成了断层的基本运动方式。在利用断层滑动速率讨论大震重复率的问题中,人们最关心的问题则是如何从总滑动量中分辨和划分出其中所包含的粘滑和蠕滑量,特别是对蠕滑量的划分,因为它直接影响着大震重复率的正确性。笔者在野外考察的基础上,对昌马活动断裂的位移量进行了分级,确定出昌马断裂带全新世以来的水平滑动量大致可划分为５个级别：３１～４１ ｍ ;２５～３１ ｍ ; １５～２２ ｍ ; ８～１３ ｍ ;１～５．５ ｍ ,同时依据古地震学方法并结合１４Ｃ断代法及断层崖形成年代的数学模拟计算,求得全新世以来在昌马断裂带上共发生５ 次古地震事件。在上述２ 项资料确定的基础上,进一步对昌马断裂带的粘滑及蠕滑量进行了划分,并给出了它们随时间的变化情况     

PRESENT KINEMATICS CHARACTERISTICS OF THE NORTHERN YUMUSHAN ACTIVE FAULT AND ITS RESPONSE TO THE NORTHEASTWARD GROWTH OF THE TIBETAN PLATEAU

Qilian Shan and Hexi Corridor, located in the north of Tibetan plateau, are the margin of Tibetan plateau's tectonic deformation and pushing. Its internal deformations and activities can greatly conserve the extension process and characteristics of the Plateau. The research of Qilian Shan and Hexi Corridor consequentially plays a significant role in understanding tectonic deformation mechanism of Tibetan plateau. The northern Yumushan Fault, located in the middle of the northern Qilian Shan thrust belt, is a significant component of Qilian Shan thrust belt which divides Yumushan and intramontane basins in Hexi Corridor. Carrying out the research of Yumushan Fault will help explain the kinematics characteristics of the northern Yumushan active fault and its response to the northeastward growth of the Tibetan plateau.Because of limited technology conditions of the time, different research emphases and some other reasons, previous research results differ dramatically. This paper summarizes the last 20 years researches from the perspectives of fault slip rates, paleao-earthquake characteristics and tectonic deformation. Using aerial-photo morphological analysis, field investigation, optical simulated luminescence(OSL)dating of alluvial surfaces and topographic profiles, we calculate the vertical slip rate and strike-slip rate at the typical site in the northern Yumushan Fault, which is(0.55±0.15)mm/a and(0.95±0.11), respectively. On the controversial problems, namely "the Luotuo(Camel)city scarp" and the 180 A.D. Biaoshi earthquake, we use aerial-photo analysis, particular field investigation and typical profile dating. We concluded that "Luotuo city scarp" is the ruin of ancient diversion works rather than the fault scarp of the 180 A.D. Biaoshi earthquake. Combining the topographic profiles of the mountain range with fault characteristics, we believe Yumu Shan is a part of Qilian Shan. The uplift of Yumu Shan is the result of Qilian Shan and Yumu Shan itself pushing northwards. Topographic profile along the crest of the Yumu Shan illustrates the decrease from its center to the tips, which is similar to the vertical slip rates and the height of fault scarp. These show that Yumu Shan is controlled by fault extension and grows laterally and vertically. At present, fault activities are still concentrated near the north foot of Yumu Shan, and the mountain ranges continue to rise since late Cenozoic.     

太白维山山前断裂活动特征的初步研究

本文立足于大量的野外第一手资料，综合解剖了太白维山山前断裂的几何结构，并就其运动学特征进行了初步探讨。认为：太白维山山前断裂第四纪以来的活动表现为正断型，其几何结构和运动特征都有着相同的分段性。我们将其划分为三段，西段结构简单，晚更新世以来无明显活动；中段结构复杂，一直强烈活动；东段活动强度较低。晚更新世晚期以来断裂（中段）的平均滑动速率０．４ｍｍ／ａ，全新世以来达到０．６７ｍｍ／ａ，而且这种速率