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1.
东昆仑断裂带秀沟段晚第四纪滑动速率研究 总被引：1，自引：0，他引：1
东昆仑断裂带是青藏高原北部一条大型左旋走滑断裂带,其滑动速率对于断裂地震危险性评价和青藏高原的地球动力学研究具有重要意义。已有的研究认为东昆仑断裂带中西段晚第四纪滑动速率稳定、均一(10~13 mm/a),但对中段精确的滑动速率研究较少。以东昆仑断裂带中段秀沟盆地一个被断错的洪积扇为研究对象,基于高分辨率卫星影像和SPOT7立体像对提取的高精度数字高程模型(DEM)恢复位错量,利用宇宙成因核素测年厘定了断错洪积扇的年龄。结果表明,该洪积扇被左旋断错(1 862±103)m,年龄为(76.55±3.20)~(106.37±3.38)ka,据此得到的平均左旋滑动速率为(20.3+3.5/-2.3)mm/a。东昆仑断裂带中段的左旋滑动速率从晚更新世到全新世存在明显的减慢趋势。 相似文献
2.
西秦岭西段光盖山-迭山断裂带坪定-化马断裂的新活动性与滑动速率 总被引：1，自引：0，他引：1
位于西秦岭西段的光盖山-迭山断裂带是由3条近平行的断裂所组成,其中坪定-化马断裂是该断裂带的主断层.坪定-化马断裂以宕昌岷江为界分为东、西两段,西段的新活动性明显强于东段.断裂西段线性特征明显,可见清晰的断层崖,不同期次的洪积扇上均有断层陡坎发育,晚第四纪以来有过明显的活动,最新一次活动的离逝时间约为1kaB.P.左右.通过对断错地貌研究得到断裂晚第四纪以来的垂直滑动速率为0.49±0.08 ～1.15±0.28mm/a,左旋滑动速率为0.51±0.13mm/a.而断裂东段由多条斜交或近于平行的断裂所组成,活动性明显减弱,没有发现最新活动的证据.在地貌上多表现为线性沟谷,向东逐渐被褶皱所替代,从基岩断面及相关地貌特征来看断裂活动性质主要表现为逆冲兼具左旋走滑运动. 相似文献
3.
西秦岭北缘断裂带黄香沟段晚第四纪 活动表现与滑动速率* 总被引：1，自引：5，他引：1
文章对西秦岭北缘断裂带黄香沟段的沉积建造、构造地貌等开展了野外调查与研究。冲沟位错、断裂剖面、山脊位错、线性槽地、洪积扇变形与断塞塘等详细的构造地貌分析,显示断裂带在黄香沟段晚第四纪具有较强的活动性,以左旋走滑兼有倾滑分量为特征。根据其中两条晚更新世末期以来的冲沟左旋水平位错平均值30.5±3.0m,及其14 C限定的冲沟发生位错的年龄为13480±240aB.P.,获得断裂晚第四纪的水平滑动速率为2.3±0.2mm/a。 同时,由断裂位错洪积扇形成的1.05±0.30m垂直位移量,与该期洪积扇形成的14 C年龄3690±100aB.P. ,估算了断裂晚第四纪的垂直滑动速率为0.28±0.08mm/a。 相似文献
4.
东昆仑断裂东端塔藏断裂压剪活动与高原隆升作用讨论 总被引：6，自引：0，他引：6
塔藏断裂位于东昆仑断裂带东端,横贯青藏高原东缘的高原内部和边缘,因属于巴颜喀拉块体向东南运移的东北侧边界带,其晚第四纪活动性质和滑动速率对认识青藏高原的构造变形模式极端重要。本文综合SPOT、中巴资源卫星等高分辨率遥感影像解译,利用冲沟、山脊、断错河流阶地、断层槽谷、反向坎等地震地貌的识别,开展详细的断错地层、地貌研究和系列年代学样品采集测试,对塔藏断裂的精细几何展布、晚第四纪活动性质、滑动速率进行详细分析。塔藏断裂自西向东可分为青藏高原内部的罗叉段、青藏高原边缘的东北村段和马家磨段,各段走向依次为113°、142°、130°,逐渐向南偏转,晚第四纪的活动表现为分段性和多期性。罗叉段全新世以左旋剪切走滑为主兼挤压活动,左旋走滑速率为2.43~2.89mm/a左右,最新地表断错事件发生在0.66±0.04ka BP以来,断层面表现出走滑断层的近垂直和张裂并发育充填楔的典型特征,塔藏断裂为东昆仑断裂系东延的主要断裂之一;马家磨段也为全新世活动断层,距今9.0±0.8ka的地层被断错,而且断层面北倾达58°。因此,对比分析塔藏断裂各段活动特征可见,西部以水平剪切运动为主,而东部走滑运动分量逐渐变弱,断面北倾、北盘上升导致的垂向分量逐渐变大。东昆仑断裂带及塔藏断裂晚第四纪走滑速率向东规则减小,并转化为横向逆冲作用和高原隆升,符合"叠瓦状逆冲转换—有限挤出模型"的特征。 相似文献
5.
《地壳构造与地壳应力文集》2010,(0)
华蓥山断裂带是四川盆地东界断裂带。前人认为该断裂带的最新活动时代为中更新世中期至晚更新世早期。作者近期野外调查发现了华蓥山断裂带晚第四纪走滑活动证据,位于华蓥山断裂带中段高县罗场镇兴场垇口村,称为兴场垇口断裂,该断裂长15km,走向NE30°,横切该区山体、造成多条水系扭曲,形成地表壮观的逆坡向右旋断错地貌。该断裂断错距今(14.86±1.26)ka地层,断裂的晚更新世晚期垂直活动速率为0.15mm/a,右旋走滑活动速率0.31mm/a,为晚更新世晚期右旋逆走滑活动断裂。 相似文献
6.
青藏高原东南部边缘的程海-宾川断裂带是一条正断与左旋走滑运动兼具的复合型活动断裂,起着调节青藏高原内部物质向东挤出的重要作用,并控制着区域的主要强震活动.基于GIS（Geographic Information System）技术,利用遥感影像和DEM（Digital Elevation Model）数据提取该区的关键构造地貌信息,对其第四纪分段活动性及特征进行了分析探讨.结果表明,程海-宾川断裂带的第四纪活动具有明显的分段性及空间差异性.其北段的金官-程海盆地主边界断层以正断层活动性质为主,并具有整个断裂带上最高的垂直活动速率;中段的期纳断裂以左旋走滑运动为主,且具有最高的走滑活动速率;南段宾川盆地东缘边界断裂也以正断层活动为主,但垂直活动速率略低于北段.总体上看,程海-宾川断裂带第四纪期间的垂直活动性由北往南降低,水平走滑活动性由中段往南北两端降低.在活动强度方面,程海-宾川断裂带百万年尺度的长期活动速率一直保持着较为稳定的状态,垂直活动速率主要集中在0.09~0.69 mm/a,水平走滑速率在0.20~1.40 mm/a.整体而言,程海-宾川断裂带中多数断裂的第四纪活动性以"中等"和"弱"为主.但历史地震活动表明,其不同段落上的未来强震活动趋势值得关注,尤其是历史强震活动相对空缺的中南段. 相似文献
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8.
佛洞庙-红崖子断裂是发育于祁连山北缘中段河西走廊南缘的一条重要的块体边界断裂,总体走向北西西,长约110 km。该断裂为一条全新世活动的逆-左旋走滑断裂,也是1609年红崖堡7 1/4 级地震的发震断裂。断裂活动形成了一系列陡坎、断层崖以及冲沟和阶地左旋等断错地貌。我们通过详细的野外考察,选择典型断错地貌进行大比例尺差分GPS测量,结合所获相应地貌面的年代数据,得到该断裂晚第四纪平均垂直滑动速率为(0.61±0.28)mm/a,水平滑动速率为(1.27±0.58)mm/a,其结果与相邻断裂相吻合。 相似文献
9.
利用冲沟、山脊等断错构造地貌的卫星遥感图像解析,结合野外构造地貌观测以及断层露头剖面的研究,详细分析了元谋断裂一平浪-江边段的晚第四纪活动特征。研究结果表明,元谋断裂一平浪-江边段在晚更新世末期-全新世以左旋走滑活动为主,兼有一定正断层分量,其晚第四纪走滑速率大致为 0.45～2.60mm/a,其中一平浪-大龙潭一带,水平滑动速率约2.00mm/a,垂直滑动速率为0.07mm/a; 木莲旧-秧田井一带,水平滑动速率接近0.53mm/a,垂直滑动速率为0.06mm/a; 乐胜古-江边一带,水平滑动速率接近1.42mm/a,垂直滑动速率为0.04mm/a。同时表明,断裂表现出至少两期明显活动的分段性特征： 较早期活动时间大致为 50.87±4.32～53.23±5.89kaB.P.,为一平浪-秧田井段的最新活动时间,且一平浪-江边整段均活动; 在秧田井-江边段,断裂最新活动时间应晚于17.92±1.52kaB.P.。2008年8月30日的攀枝花61级地震的震源机制解也显示出与元谋断裂晚第四纪左旋走滑的活动特征一致。 相似文献
10.
那拉提断裂晚第四纪活动及其反映的天山内部构造变形 总被引：3，自引：0，他引：3
对天山内部大型断裂带晚第四纪以来变形特征的研究是认知天山现今构造变形特征的重要途径。在大比例尺遥感影像解译的基础上,利用野外调查测量、探槽开挖及热释光测年的方法,对那拉提断裂进行了研究。那拉提断裂是一条晚第四纪以来仍有较强活动的大型逆冲左旋走滑断裂带,断裂带宽度巨大,由多条倾向不同的次级断裂组成,分布在南北宽数公里的范围内,这些滑动面是逆冲走滑断裂在地表分散形成的"正花状"构造。晚第四纪期间,那拉提断裂曾多次发生过断错地表的强震事件,是天山内部一条重要的地震构造带。断裂断错了那拉提山前晚第四纪以来的各级地貌面,主要表现为断层陡坎、冲沟水系和地貌面的左旋位移,根据实测陡坎高度和对应地貌面的定年,获得断裂所造成的南北向地壳缩短速率在O.8~1.1mm/a左右,表明天山内部同样存在明显的构造变形。结合目前已有的地震地质研究资料,对天山山前和天山内部吸收的变形量分配进行了讨论,认为天山南北两侧山前对变形量的吸收调节作用并不显著高于天山内部。那拉提断裂具有左旋走滑特征的发现,对于理解天山现今变形方式以及应变分配具有重要的意义。 相似文献
11.
AbstractThe Karasu Rift (Antakya province, SE Turkey) has developed between east-dipping, NNE-striking faults of the Karasu fault zone, which define the western margin of the rift and westdipping, N-S to N20°-30°E-striking faults of Dead Sea Transform fault zone (DST) in the central part and eastern margin of the rift. The strand of the Karasu fault zone that bounds the basin from west forms a linkage zone between the DST and the East Anatolian fault zone (EAFZ). The greater vertical offset on the western margin faults relative to the eastern ones indicates asymmetrical evolution of the rift as implied by the higher escarpments and accumulation of extensive, thick alluvial fans on the western margins of the rift. The thickness of the Quaternary sedimentary fill is more than 465 m, with clastic sediments intercalated with basaltic lavas. The Quaternary alkali basaltic volcanism accompanied fluvial to lacustrine sedimentation between 1.57 ± 0.08 and 0.05 ± 0.03 Ma. The faults are left-lateral oblique-slip faults as indicated by left-stepping faulting patterns, slip-lineation data and left-laterally offset lava flows and stream channels along the Karasu fault zone. At Hacilar village, an offset lava flow, dated to 0.08 ± 0.06 Ma, indicates a rate of leftlateral oblique slip of approximately 4.1 mm?year?1. Overall, the Karasu Rift is an asymmetrical transtensional basin, which has developed between seismically active splays of the left-lateral DST and the left-lateral oblique-slip Karasu fault zone during the neotectonic period. © 2001 Éditions scientifiques et médicales Elsevier SAS 相似文献
12.
《Geodinamica Acta》2001,14(1-3):197-212
The Karasu Rift (Antakya province, SE Turkey) has developed between east-dipping, NNE-striking faults of the Karasu fault zone, which define the western margin of the rift and west-dipping, N–S to N20°–30°E-striking faults of Dead Sea Transform fault zone (DST) in the central part and eastern margin of the rift. The strand of the Karasu fault zone that bounds the basin from west forms a linkage zone between the DST and the East Anatolian fault zone (EAFZ). The greater vertical offset on the western margin faults relative to the eastern ones indicates asymmetrical evolution of the rift as implied by the higher escarpments and accumulation of extensive, thick alluvial fans on the western margins of the rift. The thickness of the Quaternary sedimentary fill is more than 465 m, with clastic sediments intercalated with basaltic lavas. The Quaternary alkali basaltic volcanism accompanied fluvial to lacustrine sedimentation between 1.57 ± 0.08 and 0.05 ± 0.03 Ma. The faults are left-lateral oblique-slip faults as indicated by left-stepping faulting patterns, slip-lineation data and left-laterally offset lava flows and stream channels along the Karasu fault zone. At Hacılar village, an offset lava flow, dated to 0.08 ± 0.06 Ma, indicates a rate of left-lateral oblique slip of approximately 4.1 mm·year–1. Overall, the Karasu Rift is an asymmetrical transtensional basin, which has developed between seismically active splays of the left-lateral DST and the left-lateral oblique-slip Karasu fault zone during the neotectonic period. 相似文献
13.
《Russian Geology and Geophysics》2015,56(10):1484-1490
The Bolnay (Hangayn) fault is an active shear system which generated the M = 8.2-8.5 Bolnay earthquake of 23 July 1905, one of world’s largest recorded intracontinental event. The fault follows the Mesozoic suture formed during the closure of the Mongolia-Okhotsk ocean. The Late Cenozoic faulting in the region was induced by propagation of strain from the India-Eurasia collision that had reached Mongolia at about 5 ± 3 Ma. The left-lateral strike slip almost all over the fault length is compensated in its western end by Late Quaternary reverse motion. We estimated coseismic slip associated with the event of 1905 and the previous earthquakes in the eastern fault end and checked whether vertical offset compensates the strike slip in this part as well. The 1905 coseismic slip measured from a displaced dry stream bed and pebble bars in the Hasany-Gol river valley was 6.5-7.5 m. The 13 ± 1 m left-lateral displacement of pebble bars in the same valley represents a cumulative slip of two events. Paleoseismological studies across the strike of surface ruptures reveal at least two generations of rupture in two events that postdated the deposition of sediments with a 14C age of 4689 ± 94 yr. Hypsometry of the alluvial surface in the zone of deformation shows gradual elevation increase toward the mountains, but without abrupt change across the fault. This means the absence of vertical offset and reactivation of the fault as a left-lateral strike slip. The horizontal slip in the eastern extension of the Bolnay fault is compensated rather by parallel fault-bounded pull-apart basins trending northeastward oblique to the principal fault strike. The age of their sedimentary fill suggests no older than middle Pleistocene normal faulting that compensated the Bolnay strike slip. 相似文献
14.
The Eastern Kunlun fault zone (EKLF) is a large left-lateral strike-slip fault, whose slip rate is meaningful to seismic hazard assessment and geodynamics of the Tibetan Plateau. Previous studies suggested that the late Quaternary average slip rate was stable and uniform (10~13 mm/a) in the central and western segment of the EKLF. But there were a few researches of accurate slip rate in the central segment on the EKLF. Therefore, we focused on an offset and well preserved alluvial fan from Xiugou basin, located in the east of Xidatan-Dongdatan, to make it clear. Moreover, we used high-resolution satellite images and digital elevation model extracted from SPOT7 stereo image pairs to restore the offset alluvial fan, and combined terrestrial cosmogenic nuclides method, including 13 quartz-rich samples from this fan surface, 1 quartz-rich sample from the main active channel bed and 1 10Be depth profile from this fan edge to eliminate the 10Be concentration of inheritance accurately, with 1 optically stimulated luminescence sample to obtain the reliable age of this alluvial fan together. Referring to field observations, this alluvial fan was offset left-laterally by (1 862±103) m, and its age is (76.55±3.20)~(106.37±3.38) ka which can be determined through the actual geologic setting and improving chi-square test. Thus, we used the Monte Carlo method to obtain a left-lateral slip rate of (20.3+3.5/-2.3) mm/a with 68% confidence envelopes since the late Pleistocene in the Xiugou basin. As a result, combining with the results of previous studies, the left-lateral slip rate indicated that the obviously decreasing activity transferred from late Pleistocene to Holocene on the central segment of the EKLF. 相似文献
15.
阿尔金断裂系西段——康西瓦断裂的 晚第四纪构造地貌特征研究* 总被引：17，自引：9，他引：17
阿尔金断裂带是青藏高原北部的一条大型左旋走滑断裂带,近EW向延伸2000多公里, 它构成了青藏高原与塔里木盆地之间的重要地质边界。康西瓦断裂位于阿尔金断裂带西段, 呈WNW-ESE向延伸约 700km。文章在高分辨率卫星遥感图像(印度遥感卫星5.8m分辨率)和数字高程地形模型(DEM)数据分析的基础上,并结合野外构造地貌考察观测,对康西瓦断裂的第四纪构造活动及其地貌特征进行了初步研究。沿断裂带发育的系统错断水系、错断冲积扇、挤压脊、走滑拉分盆地等典型构造地貌特征表明,该断裂晚第四纪经历了强烈的左旋走滑活动。同时,研究还揭示沿康西瓦断裂发育了一条长约80km的地表地震破裂带,最大同震左旋水平错位为4m,估算产生该地表破裂带的地震是一矩震级为Mw7.3的大地震。 另外,文章根据不同年代地表地貌特征的左旋错位距离,估算出康西瓦断裂晚第四纪以来的长期走滑速率为8~12mm/a,远低于早期估算的20~30mm/a,但是与阿尔金断裂带中、东段的地质估算结果9±2mm/a及GPS测量结果9±4mm/a接近。 相似文献
16.
青藏高原中部第四纪左旋剪切变形的地表地质证据 总被引：7，自引：5，他引：2
在青藏铁路的格尔木—拉萨段进行的活动断裂调查发现,在沱沱河—五道梁之间宽约150km的地段内发育了多条由北西西向次级断层左列分布构成的北西西向和北西向左旋张扭性断裂带,在断裂带之间则发育"S"型的北东向裂陷盆地和雁列分布的菱形裂陷盆地,盆地边界断裂也为左旋张扭性质。上述断裂带和裂陷带主要形成于第四纪,它们构成了宽约150km的不均匀的左旋简单剪切变形域,该变形域的整体活动性较弱,属于弱的不均匀剪切变形域。但其中的二道沟断陷盆地是个例外,该盆地边界断裂的垂直活动速率约为0 5mm/a,左旋活动速率介于0 8～1 0mm/a之间。而在整个左旋剪切变形带累计的左旋走滑速率不会超过6mm/a,它们所调节的昆仑山与唐古拉山之间的地壳南北缩短量也可能仅占总缩短量的15%～30%。上述弱剪切变形域与强烈左旋走滑的昆仑断裂系共同构成了高原中部的左旋剪切变形带,它们在印度板块与欧亚板块强烈碰撞的构造动力学背景下,起着调节青藏高原南北向缩短的重要作用。 相似文献
17.
Uniform Strike-Slip Rate along the Xianshuihe-Xiaojiang Fault System and Its Implications for Active Tectonics in Southeastern Tibet 总被引：6，自引：0，他引：6
Yasutaka IKEDA 《《地质学报》英文版》2006,80(3):376-386
Recent studies on the Xianshuihe-Xiaojiang fault system suggest that the Late Quaternary strike-slip rate is approximately uniform along the entire length of the fault zone, about 15±2 mm/a. This approximately uniform strike slip rate strongly supports the clockwise rotation model of the southeastern Tibetan crust. By approximating the geometry of the arc-shaped Xianshuihe-Xiaojiang fault system as a portion of a small circle on a spherical Earth, the 15±2 mm/a strike slip rate corresponds to clockwise rotation of the Southeastern Tibetan Block at the (5.2±0.7)×10-7 deg/a angular velocity around the pole (21°N, 88°E) relative to the Northeast Tibetan Block. The approximately uniform strike slip rate along the Xianshuihe-Xiaojiang fault system also implies that the Longmenshan thrust zone is not active, or at least its activity has been very weak since the Late Quaternary. Moreover, the total offset along the Xianshuihe-Xiaojiang fault system suggests that the lateral extrusion of the Southeastern Tibetan Block relative to Northeastern Tibetan Block is about 160 km and 200-240 km relative to the Tarim-North China block. This amount of lateral extrusion of the Tibetan crust should have accommodated about 13-24% convergence between India and Eurasia based on mass balance calculations. Assuming that the slip rate of 15±2 mm/a is constant throughout the entire history of the Xianshuihe-Xiaojiang fault system, 11±1.5 Ma is needed for the Xianshuihe-Xiaojiang fault system to attain the 160 km of total offset. This implies that left-slip faulting on the Xianshuihe-Xiaojiang fault system might start at 11±1.5 Ma. 相似文献
18.
5·12汶川Mw7.9级地震为罕见的、地壳尺度位移配分于多条平行断裂的板内逆冲走滑型地震。在2条北东走向、近平行的主要地表破裂间,发育北西走向的小鱼洞地表破裂。介绍了对小鱼洞北西向地表破裂的精细填图。小鱼洞地表破裂空间上位于灌县-江油与映秀-北川断裂间,全长约8km,总体走向310°,为南西盘抬升、逆冲兼具左旋走滑性质。地表破裂在南东端走向变化较大,从300~310°变为南北向,并与灌县-江油地表破裂带的磁峰段相连。小鱼洞地表破裂的垂向位错自北西往南东方向递减,北西端陡坎高度最大3.4m,南东端则小于0.2m,衰减梯度约为0.5m/km。左旋走滑位移测量点较少,集中在中段的小鱼洞镇附近,所测最大左旋走滑位移约为2.2m,一般走滑位错与同处垂直位错具有同步变化的特征。小鱼洞断裂近地表的倾角较缓,为30°±15°。结合已有地貌、地球物理和地质研究结果,提出小鱼洞断裂是向下与灌县-江油断裂交会的侧向断坡,位于映秀-北川断裂中南段间的断面倾角差异的撕裂部位,连接映秀-北川和灌县-江油断裂。在运动学上,认为小鱼洞断裂是以斜向断坡为几何形态的撕裂断裂,调节了北东走向的主断裂的运动学横向差异。小鱼洞断裂上的同震位移矢量与N70°、80°E的区域主压应力场方向匹配。这一方向与龙门山高原边界斜交。 相似文献
19.
《International Geology Review》2012,54(9):991-1012
The active kinematics of the eastern Tibetan Plateau are characterized by the southeastward movement of a major tectonic unit, the Chuan-Dian crustal fragment, bounded by the left-lateral Xianshuihe–Xiaojiang fault in the northeast and the right-lateral Red River–Ailao Shan shear zone in the southwest. Our field structural and geomorphic observations define two sets of young, active strike–slip faults within the northern part of the fragment that lie within the SE Tibetan Plateau. One set trends NE–SW with right-lateral displacement and includes the Jiulong, Batang, and Derong faults. The second set trends NW–SE with left-lateral displacement and includes the Xianshuihe, Litang, Xiangcheng, Zhongdian, and Xuebo faults. Strike–slip displacements along these faults were established by the deflection and offset of streams and various lithologic units; these offsets yield an average magnitude of right- and left-lateral displacements of ～15–35 km. Using 5.7–3.5 Ma as the time of onset of the late-stage evolution of the Xianshuihe fault and the regional stream incision within this part of the plateau as a proxy for the initiation age of conjugate strike–slip faulting, we have determined an average slip rate of ～2.6–9.4 mm/year. These two sets of strike–slip faults intersect at an obtuse angle that ranges from 100° to 140° facing east and west; the fault sets define a conjugate strike–slip pattern that expresses internal E–W shortening in the northern part of the Chuan-Dian crustal fragment. These conjugate faults are interpreted to have experienced clockwise and counterclockwise rotations of up to 20°. The presence of this conjugate fault system demonstrates that this part of the Tibetan Plateau is undergoing not only southward movement, but also E–W shortening and N–S lengthening due to convergence between the Sichuan Basin and the eastern Himalayan syntaxis. 相似文献
20.
青海鄂拉山断裂带晚第四纪构造活动及其所反映的青藏高原东北缘的变形机制 总被引：11，自引：0，他引：11
鄂拉山断裂带是分隔青海乌兰盆地 (柴达木盆地的一部分 )与茶卡—共和盆地的一条重要边界断裂 ,长约 2 0 7km ,由 6条规模较大的主要以右阶或左阶次级断裂段羽列而成 ,阶距约 1～ 3.5km。该断裂右旋走滑的起始时代为第四纪初期 ,约在 1.8～ 3.8MaB .P .期间 ,大的地质体累积断错约 9～12km。断裂新活动形成了一系列山脊、冲沟和阶地等的右旋断错及断层崖、断层陡坎等。晚更新世晚期以来 ,鄂拉山断裂带的平均水平滑动速率为 (4 .1± 0 .9)mm/a ,垂直滑动速率为 (0 .15± 0 .1)mm/a。鄂拉山地区的构造变形受区域NE向构造应力作用下的剪切压扁与鄂拉山断裂的右旋剪切和挤压的共同影响 ,共和—茶卡盆地和乌兰盆地均属于走滑挤压型盆地。青藏高原东北缘地区在区域性北东向挤压的作用之下 ,应变被分解为沿北西西向断裂的左旋走滑和沿北北西向断裂的右旋走滑运动 ,形成一对共轭的剪切断裂。鄂拉山断裂及其他北北西走向断裂的发展演化和变形机制表明青藏高原东北缘向东的挤出和逃逸是非常有限的。 相似文献