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1.
阿尔金断裂东段的构造转换模式   总被引：1，自引：0，他引：1  
大型走滑断裂控制着青藏高原的变形,众多学者通过阿尔金断裂来探索青藏高原北部的构造变形过程。基于野外调查和前人的研究结果可知阿尔金断裂的滑动速率在肃北—疏勒河口段表现为三联点两侧的突降,祁连山西段的逆冲和走滑断裂吸收了阿尔金断裂的左旋位移。由于祁连山内部次级断裂活动性的增强,现存阿尔金断裂连续地表破裂终止于酒泉盆地西侧,但位于其东侧的断裂系仍属于阿尔金断裂。在Kohistan岛弧与欧亚板块碰撞之后,青藏高原沿阿尔金断裂曾发生滑动速率近一致的侧向挤出,断裂两侧此时并未发生明显的隆起。随后东昆仑造山带和祁连山造山带的先后大规模隆升,高原的北东向挤出迅速减弱。阿尔金断裂北东向挤出能力与东昆仑造山带和祁连山造山带的隆起存在明显的耦合作用。  相似文献   

2.
位于青藏高原北缘的酒西盆地,出露有完整的晚始新世地层,真实地记录了周缘构造的运动,使其成为研究高原北缘新生代构造活动的最佳场所之一.基于酒西盆地11条沉积剖面的沉积相、重矿物和古水流研究,建立了火烧沟组-白杨河组高精度的沉积格架,识别出盆地在晚始新世主要为走滑盆地,沉积形态主要受阿尔金断裂左行走滑作用控制.阿尔金断裂强烈的走滑作用受到北部阿拉善地体的阻挡,在酒西盆地北部形成一个前锋带.随后,高原内部强烈的南-北向挤压作用沿酒西盆地的刚性基底向南传递到北祁连断裂,形成了新近纪早期酒西前陆盆地的雏形.  相似文献   

3.
Initiation and Long-Term Slip History of the Altyn Tagh Fault   总被引：1，自引：0，他引：1  
《International Geology Review》2012,54(12):1087-1093
New Tertiary piercing points along the eastern and central Altyn Tagh fault, the northern boundary of the Tibetan Plateau, allow construction of the first well-defined time-displacement curve for the fault. Displacement-history analysis indicates: (1) late Oligocene-earliest Miocene inception of the Altyn Tagh fault; (2) 375 ± 25 km of total left-lateral slip on the eastern and central segment of the Altyn Tagh fault; and (3) an average long-term Cenozoic slip rate of approximately 12-16 mm/year. These results demonstrate that Himalayan deformation propagated well into the interior of Asia by early Miocene time and that a significant amount of India-Asia convergence was accommodated by sinistral slip on the Altyn Tagh fault.  相似文献   

4.
阿尔金断裂东端破裂生长点的最新构造变形*   总被引：3，自引：1，他引：3       下载免费PDF全文
阿尔金断裂与祁连山北缘断裂的交汇部位是阿尔金断裂向东扩展的新破裂生长点,两断裂构造与新生的红柳峡断裂构成似三联点构造。破裂生长点附近的最新构造变形表现为:阿尔金断裂的旋转隆升和向北扩展;祁连山北缘断裂的逆冲推覆兼右旋走滑;红柳峡断裂的挤压拖曳弯曲,它们共同受制于青藏高原的强烈隆升和向外扩张作用。推测阿尔金断裂自西而东的破裂扩展就是似三联点构造逐一形成而又被切割贯通的过程。阿尔金断裂以蠕滑活动为主,2002年玉门地震与祁连山北缘逆冲断裂及其伴生的调节断层的活动相关。  相似文献   

5.
Although it has long been proposed that active crustal shortening within the Qilian Shan accommodates slip along the Altyn Tagh fault, questions regarding the temporal and spatial amount of slip transfer remain debated. Traditional shortening calculations cannot yet be made accurately, because the geology is not known well enough. Following the view that long, linear drainage basins in the north‐western Qilian Shan developed in response to internal shortening associated with slip transfer along the Altyn Tagh fault, we targeted this special irregular drainage basin geometry to develop an alternative way to estimate shortening. We infer a total of ~66 km of shortening in the western Qilian Shan with a north‐eastward decrease in the magnitude of shortening. This ~39% shortening strain is comparable to previous estimates. Estimates of dates of initiation support the view that significant shortening and topographical growth within the north‐western Qilian Shan occurred in post‐Middle Miocene time.  相似文献   

6.
阿尔金山位于青藏高原北部边缘,在高原隆升和演化过程中扮演着重要的角色。但是,关于它的新生代隆升历史现今仍存在较大的争议。阿尔金山北麓若羌凹陷新生代接受来自山脉的剥蚀物质。因此,凹陷内的沉积特征记录了阿尔金山新生代隆升的重要信息。本文利用石油钻井编录资料及地震剖面,通过对盆地区新生代各个地层之间的接触关系、沉积相组合和沉积速率变化进行研究,结果显示阿尔金山34Ma以来的隆升分为两阶段:第一阶段为34~20.4Ma,持续低速隆升;第二阶段为16Ma至现今,急剧快速隆升。结合前人研究成果,认为渐新世—早中新世,阿尔金断裂作为一个局限在中、下地壳的韧性剪切带造成阿尔金山一带产生大范围的地表隆起,控制了山脉在第一阶段的持续低速隆升;中中新世以来,阿尔金断裂大规模左行走滑,青藏高原北缘主要通过地壳缩短的形式释放应力,控制了山脉在第二阶段的急剧快速隆升。  相似文献   

7.
阿尔金断裂带对青藏高原北部生长、隆升的制约   总被引：59，自引：3，他引：59  
大量的同位素年代学证据表明(古)阿尔金断裂带可能形成于三叠纪,后又经历了侏罗纪、白垩纪的强烈左旋走滑活动,自印度板块与欧亚大陆碰撞后阿尔金断裂再次活动。主要的走滑活动发生在:(1)245~220Ma;(2)180~140Ma;(3)120~100Ma;(4)90~80Ma;(5)60~45Ma;(6)渐新世至中新世;(7)上新世至更新世以及(8)全新世。沿阿尔金断裂带,伴随左旋走滑活动形成一系列的逆冲断裂和正断裂,反映走滑过程中伴随隆升作用的存在,并且形成自北向南包括祁连山、大雪山、党河南山、柴北缘山、祁漫塔格山和昆仑山,表明阿尔金断裂带制约着青藏高原北部的生长和隆升。阿尔金断裂带东、西两端的白垩纪和新生代火山活动是断裂走滑活动的响应。  相似文献   

8.
The question of whether or not the Altyn Tagh fault is a large-scale extrusion boundary is critical for understanding the role of lateral extrusion in accommodating the Indo-Asian convergence and in building the Tibetan Plateau. Oligocene conglomerate clasts in the eastern Xorkol basin are low-grade slate, phyllite, sandstone, dacite and carbonate, and associated paleocurrent indicators evince sediment derivation from the opposing side of the Altyn Tagh fault. Matching these clasts with similar basement rocks in the North Qilian and Tuolainanshan terranes requires post-Oligocene left-lateral offset of 380 ± 60 km on the eastern segment of the Altyn Tagh fault, suggesting large-scale extrusion along the fault in the Cenozoic (Yue, Y.J., Ritts, B.D., Graham, S.A., 2001b. Initiation and long-term slip history of the Altyn Tagh fault. International Geological Review 43, 1087–1094.). In order to further define this piercing point, the detrital zircon pattern of Oligocene sandstone from the Xorkol basin and the zircon ages of basement on the southern side of the fault were established by ion microprobe dating. Characterized by strong peaks between 850 and 950 Ma and the absence of Paleozoic and Mesozoic ages, the detrital zircon age pattern of the Oligocene sandstone matches the age distribution of zircon-bearing rocks of the Tuolainanshan terrane. This match requires 360 ± 40 km of post-Oligocene left-lateral displacement on the eastern segment of the Altyn Tagh fault, supporting as well as refining the previously reported lithology-based cross-fault match. At least one of the following three extrusion scenarios must have existed to accommodate this large offset: (1) northeastward extrusion along the Altyn Tagh–Alxa–East Mongolia fault, (2) eastward extrusion along the Altyn Tagh–North Qilian–Haiyuan fault, and (3) northeastward extrusion of northern Tibet as a Himalaya-scale thrust sheet along the North Qilian–Haiyuan fault. We prefer the first scenario inasmuch as rapidly growing evidence for Cenozoic strike-slip activity on the Alxa–East Mongolia fault and mid-Miocene exhumation of northern Tibet supports it.  相似文献   

9.
The lithospheric strike‐slip Altyn Tagh Fault has accommodated hundreds of kilometres of displacement between the Qaidam and Tarim blocks since its Eocene reactivation. However, the way the deformation is accommodated in the Qilian Shan and further east remains uncertain. Based on 360 km of north‐eastward migration of the relatively rigid Qaidam block along the Altyn Tagh Fault and 3D isovolumetric balancing of the crustal deformation within the Altyn Tagh Fault–Qilian Shan system, we demonstrate that 250 ± 28 km (43.8–49.4%) of N20E directed crustal shortening and an additional ~250–370 km of eastward motion of the Qilian Shan crust must be accounted for by strike‐slip faulting in the Qilian Shan and crustal thickening in the Qinling area, as well as by extension in the adjoining North China block graben systems.  相似文献   

10.
THREE-DIMENSIONAL DEFORMATION ALONG THE ALTYN TAGH FAULT ZONE AND UPLIFT OF THE ALTYN MOUNTAIN, NORTHERN TIBET  相似文献   

11.
康西瓦断裂带晚新生代构造地貌特征及其构造意义   总被引：2，自引：0，他引：2       下载免费PDF全文
文章详细调查了康西瓦断裂带发育的断层崖、断层陡坎、地震破裂带、错断山脊、拉分盆地、挤压脊、偏心洪积扇、错断水系等新构造运动形迹,这些新构造运动形迹表明了康西瓦断裂带在晚新生代以来发生了强烈的左旋走滑运动,并兼有正滑运动分量。数字地形高程模型(DEM)分析表明康西瓦断裂西端终止于塔什库尔干谷地东部的瓦恰河谷内,东端与著名的阿尔金断裂带相连。如果以喀拉喀什河和玉龙喀什河为参照系,康西瓦断裂晚新生代以来的左旋走滑累积位移量可达 80～85km,根据断裂带 8～12mm/a的长期走滑速率,推测康西瓦断裂带新生代以来的左旋走滑运动开始于约10Ma。结合我们获得的断裂带两侧岩浆岩的年龄,表明康西瓦断裂带左旋走滑运动的开始时代为晚中新世,现今康西瓦地区的构造地貌格局很可能是中新世晚期以来强烈的左旋走滑运动形成的。  相似文献   

12.
Project INDEPTH (InterNational DEep Profiling of Tibet and the Himalaya) is an interdisciplinary program designed to develop a better understanding of deep structures and mechanics of the Tibetan Plateau. As a component of magnetotelluric (MT) work in the 4th phase of the project, MT data were collected along a profile that crosses the eastern segment of the Altyn Tagh fault on the northern margin of the plateau. Time series data processing used robust algorithms to give high quality responses. Dimensionality analysis showed that 2D approach is only valid for the northern section of the profile. Consequently, 2D inversions were only conducted for the northern section, and 3D inversions were conducted on MT data from the whole profile. From the 2D inversion model, the eastern segment of the Altyn Tagh fault only appears as a crustal structure, which suggests accommodation of strike slip motion along the Altyn Tagh fault by thrusting within the Qilian block. A large-scale off-profile conductor within the mid-lower crust of the Qilian block was revealed from the 3D inversion model, which is probably correlated with the North Qaidam thrust belt. Furthermore, the unconnected conductors from the 3D inversion model indicate that deformations in the study area are generally localized.  相似文献   

13.
NORMAL-SLIP ALONG THE NORTHERN ALTYN TAGH FAULT, NORTH TIBET   总被引：1，自引：0，他引：1  
NORMAL-SLIP ALONG THE NORTHERN ALTYN TAGH FAULT, NORTH TIBET  相似文献   

14.
THE FORMATION AND EVOLUTION OF ALTYN TAGH FAULT SYSTEM AND ITS RELATIONSHIP TO THE GROWTH OF TIBETAN PLATEAUtheNational(G19980 4 0 80 0 )andthefundofOpeningLaboratoriesofGeomechanics  相似文献   

15.
柴达木盆地东北部新近纪构造旋转及其意义   总被引：4，自引：1，他引：3  
青藏高原东北缘构造变形的研究是认识高原隆起过程、机制和印度—欧亚板块碰撞远程效应的重要途径。柴达木盆地是印度－欧亚板块碰撞后南北向挤压应力为动力背景的高原东北部内陆盆地,沉积物主要来自于周边山地,完整的保存了新生代以来高原隆升的详细记录。通过柴达木盆地东北部瑙格剖面精细古地磁及构造旋转研究发现,20.1～15.1Ma以及15.1～8.2Ma柴达木盆地分别发生了9.7°±7.4°和6.4°±4.4°的顺时针旋转,约8.2Ma后,柴达木盆地东北部瑙格地区发生了16°±7.5°的逆时针快速旋转。通过分析认为,前两次的顺时针构造旋转事件可能与阿尔金断裂的左旋走滑有关。而约82Ma以来的逆时针旋转事件属于柴达木盆地东北部瑙格地区的局部旋转,可能与温泉断裂的右旋走滑有关,说明青藏高原东北部在昆仑山、阿尔金山和祁连山三条巨型断裂系左旋相对运动的宏观控制下形成的NNW向温泉右旋走滑断裂开始走滑的年代为约8Ma。  相似文献   

16.
自新生代以来,柴达木盆地西北缘各构造单元受青藏高原持续挤压和阿尔金断裂走滑的影响,构造变形复杂,发育有多种不同性质,不同规模的断裂.地震属性技术是三维(3D)地震资料解释和构造分析的可靠依据,有助于客观、准确的揭示断裂的空间分布情况,是复杂地区地质解释的重要工具.本文利用地震属性技术,对位于阿尔金断裂南侧柴达木盆地西部的小梁山背斜深、浅层进行详细的断裂解译,发现该地区深部发育早期EW向逆冲断层;晚期由于阿尔金断裂大规模走滑的作用,形成由深部引发的NW向“楔形”逆冲断层,深部NW向断层的活动引发浅层的滑脱褶皱.综合分析认为阿尔金断裂新生代的活动分为早期隆升形成EW向斜向逆冲断层,晚期走滑运动发育控制现今背斜形态的NW向断层,具有两阶段活动的特点.  相似文献   

17.
新生代以来,中国西部的一系列古老造山带和盆地在印-亚板块汇聚作用下重新复活,在青藏高原外围形成了现今全球最大的陆内挤压构造域,被称为环青藏高原盆山体系,其形成过程与机制对深入认识陆-陆碰撞如何影响大陆内部变形有重要意义。柴达木盆地是中国西部重要的新生代沉积盆地,四周均被巨型造山带所围限,共同构成了环青藏高原盆山体系北东段的主体。本文利用最新的石油地震勘探数据、地表地质和已发表的深反射地震数据,将上地壳变形与岩石圈深部变形有机结合,系统刻画了柴达木盆地与周缘三大造山带之间岩石圈尺度的构造耦合关系,在此基础上探讨环青藏高原盆山体系北东段的盆山汇聚过程与机制。柴达木盆地与南侧祁曼塔格—东昆仑山、北东侧南祁连山之间在上地壳尺度发育一系列倾向造山带的基底卷入高角度逆断裂体系,自新生代早期就开始活动,以垂直的基底抬升为主,水平缩短量有限;在下地壳和岩石圈地幔深度则发育倾向盆地一侧的深大断裂,使得柴达木盆地与周缘造山带之间发生截然的莫霍面错断。这些变形特征揭示柴达木盆地与南侧祁曼塔格—东昆仑山、北东侧南祁连山之间发育岩石圈尺度的构造楔,即盆地的岩石圈楔入至增厚的造山带下地壳,其发育主要受盆地与造山带...  相似文献   

18.
阿尔金-祁连山位于青藏高原北缘, 其新生代的隆升-剥露过程记录了高原变形和向北扩展的历史, 对探讨高原隆升动力学具有重要意义。本文采用岩屑磷灰石裂变径迹测年分析, 利用岩屑的统计特征限定阿尔金-祁连山新生代的隆升-剥露过程。磷灰石裂变径迹测试结果表明, 阿尔金-祁连山地区存在4个阶段的抬升冷却: 21.1~19.4 Ma、13.5~10.5 Ma、9.0~7.3 Ma、4.3~3.8 Ma。其中, 4.3~3.8 Ma抬升冷却事件仅体现在祁连山地区, 9.0~7.3 Ma抬升冷却事件在区内普遍存在, 且9.0~7.3 Ma隆升-剥露造就了现代阿尔金-祁连山的地貌。区域资料分析表明, 9~7 Ma(或者8~6 Ma)期间, 青藏高原北缘、东缘, 甚至整个中国西部地区发生了大规模、区域性的抬升, 中国现今"西高"的构造地貌形态可能于当时开始形成。阿尔金-祁连山地区4期抬升冷却事件与青藏高原的隆升阶段有很好的对应关系, 应该是对印度-欧亚板块碰撞的响应。  相似文献   

19.
LARGEST ALTYN TAGH LITHOSPHERIC SHEAR FAULT IN CENTRAL ASIA   总被引：1，自引：0，他引：1  
LARGEST ALTYN TAGH LITHOSPHERIC SHEAR FAULT IN CENTRAL ASIA  相似文献   

20.
The Quaternary activity of the faults at the eastern end of the Altyn Tagh fault, including the Dengdengshan–Chijiaciwo, Kuantanshan and Heishan faults, was studied on the basis of interpretation of satellite images, trenching, geomorphologic offset measurements and dating. The Altyn Tagh fault has extended eastwards to Kuantanshan Mountain. The left–slip rates of the Altyn Tagh fault decreased through the Qilianshan fault and were transformed into thrust and folds deformation of many NW–trending faults within the Jiuxi basin. Meanwhile, under NE–directed compression of the Tibetan plateau, thrust dominated the Dengdengshan–Chijiaciwo fault northeast of the Kuantanshan uplift with a rate lower than that of every fault in the Jiuxi basin south of the uplift, implying that tectonic deformation is mainly confined to the plateau interior and the Hexi Corridor area. From continual northeastward enlargement of the Altyn Tagh fault, the Kuantanshan uplift became a triangular wedge intruding to the east, while the Kuantanshan area at the end of this wedge rose up strongly. In future, the Altyn Tagh fault will continue to spread eastward along the Heishan and Jintananshan faults. The results have implications for understanding the propagation of crustal deformation and the mechanism of the India–Eurasian collision.  相似文献   

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