共查询到19条相似文献，搜索用时 281 毫秒
1.
通过分析高精度数字化SPOT卫星影像 ,结合野外考察和年代学测试 ,对阿尔金南缘走滑断裂带的 3个典型走滑断层断错地貌点进行了研究。在安南坝沟 ,阿尔金南缘走滑断裂带一主要分支自 (9.36± 0 .73)kaBP以来的左旋滑动速率为 (7.5± 1.7)mm/a ;在七个泉子阿尔金南缘走滑断裂带有 4条分支 ,其中 1条规模较小的断层分支自 (13 86± 1 0 7)kaBP以来的左旋滑动速率为 (2 .3±0 5 )mm/a ,由此推断七个泉子附近断裂带全新世以来的滑动速率为 (6 .9± 1.5 )～ (9.2± 2 .0 )mm/a ;约马克其断裂带自 (4 .73± 0 .38)kaBP以来的左旋滑动速率为 (10 .6± 3.0 )mm/a。综合以上各点结果 ,阿尔金南缘走滑断裂带中段 88°30′E与 93°0 5′E之间全新世以来的水平滑动速率为 7～ 11mm/a ,与最新的GPS观测结果非常接近 相似文献
2.
阿尔金断裂带作为青藏高原北部边界 ,其走滑量和走滑速率一直为地学界所关注 ,对这样一条大陆内部巨型走滑断裂带的滑动速率进行研究 ,对于了解阿尔金断裂带左旋走滑和青藏高原北部隆升之间的耦合关系 ,具有重要意义。在阿尔金断裂带东段的疏勒河口以西 ,阿尔金断裂错断了几条规模相近的河流阶地和洪积扇 ,形成典型的走滑断层断错地貌。通过对这些典型断错地貌点的地貌观测和年代学研究 ,得到阿尔金断裂带东段石堡城以东疏勒河以西自 2 0kaBP以来的滑动速率约为 4～ 5mm/a。自 50kaBP以来 ,阿尔金断裂带东段断层平均滑动速率具有较高的时间、空间一致性 ,约为 4～ 6mm/a ,表明利用河流阶地和洪积扇位错作为断层走滑位移标志计算断层滑动速率 ,具有较高的可信度 相似文献
3.
通过分析中国地壳运动观测网络的GPS数据得到川滇地区地壳水平运动速度场 ,由此划分活动块体并分析其运动特征。结果表明 :相对欧亚板块 ,滇中、雅江和中甸次级块体的顺时针转动速率分别为 0 37°± 0 16°/Ma ,0 84°± 0 39°/Ma和 0 90°± 0 39°/Ma ,造成块体间跨木里弧形断裂带约 3mm/a的SN向挤压、丽江 -大理断裂带约 4mm/a的EW向拉张和理塘断裂带约 6mm/a的近EW向拉张。鲜水河断裂带左旋走滑速率 8～ 10mm/a ,安宁河 -则木河 -小江断裂带左旋走滑 5～6mm/a。龙门山断裂带没有明显的地壳消减 ,而断裂带西北约 15 0km处有一形变速度阶跃带 ,右旋走滑速率 4～ 5mm/a。阶跃带两侧的岷山块体和阿坝地区逆时针转动速率分别为 0 13°± 0 0 8°/Ma和0 5 3°± 0 19°/Ma。鲜水河 -小江断裂带以南、以西地区 ,青藏高原物质的E向挤出和重力滑塌造成川滇块体东移 ,在东部相对稳定的华南地块的阻挡下 ,川滇块体沿鲜水河 -小江断裂带由东转向南运动 ,从而引起川滇块体内部各次级块体的顺时针转动 相似文献
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震后野外考察表明 ,2 0 0 1年 11月 14日昆仑山库赛湖地震 (MS8 1)发生在青藏高原北部东昆仑断裂带库赛湖段上 ,发震断层具有高速率左旋滑动的基本特征 ,晚更新世晚期以来的平均滑动速率达 (14 8± 2 4 )mm/a ;地震地表破裂带沿库赛湖段西起布喀达板峰东缘 (91°0 8′E) ,向东经库赛湖北缘、青藏公路 2 894里程碑、玉珠峰南麓 ,东止于青藏公路东 70km附近 (94°4 8′E) ,地震地表破裂带沿N70°～ 90°W走向线状展布 ,全长约 35 0km ,由一系列走向N4 5°～ 5 0°E拉开状张裂缝、走向N6 0°～ 75°E张剪切裂缝、走向N80°W剪切裂缝以及隆起鼓包或开裂陷坑等斜列状组合而成 ,显示出纯剪切走滑的破裂特征 ,最大左旋水平位移 6m ;宏观震中位于昆仑山口西 80～ 90km附近的库赛湖东北角山麓地带 ,地震地表破裂带宽度 30 0m ,在库赛湖北岸至山麓地带的地震地表破裂带和由地震动或重力效应引起的次生破裂带总宽度可达 2km。库赛湖地震地表破裂的左旋走滑特征表明 ,青藏高原物质确实存在着向东的滑移或流动 ,东昆仑断裂带东部与库赛湖段斜列的东大 相似文献
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阿尔金活动断裂带东段的滑动速率由西向东逐渐减小,而肃北是阿尔金断裂东段滑动速率的"突变点"之一。在肃北以东分布多条分支断裂,野马河北侧断裂便是其中的一条。野马河北侧断裂长约30km,总体走向NEE,该断裂沿野马河盆地北侧山前洪积扇延伸,沿断裂具有大量的左旋走滑和逆冲等地貌现象,多处冲沟出露有断层剖面。野外调查结果表明该断裂是一条左旋走滑兼逆冲断裂,错断了晚更新世时期形成的洪积扇或冲沟阶地。通过实测得到地貌面左旋、垂直错动数据,并采集样品测试相关地貌面的年龄,估算该断裂晚更新世以来的平均水平滑动速率为(1.27±0.18)mm/a,平均逆冲速率为(0.4±0.07)mm/a,该断裂分解了阿尔金断裂东段的部分运动量 相似文献
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文中通过对东昆仑活动断裂带托索湖至玛曲段的实际野外测量,获得了该段上的1组断裂位错实测数据和14C及TL测年样品。通过室内分析研究,发现大体以阿尼玛卿山玛积主峰为界,东昆仑活动断裂带托索湖至玛曲段可再分为花石峡段和玛沁段2个在几何上不连续的段落,花石峡段的全新世水平滑动速率(115±11)mm/a明显高于玛沁段(70±06)mm/a。此外,由于断裂而引起的断裂两侧的差异垂直隆升速率,花石峡段自4kaBP以来约为(21±03)mm/a,玛沁段自10kaBP以来约为055mm/a。这种差异垂直隆升速率的明显变化,一方面反映了东昆仑活动断裂带不同段落上活动的差异,另一方面也可能反映了研究区内全新世以来的快速隆升 相似文献
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以ldquo;中国地壳运动观测网络rdquo;区域站在海原断裂带附近的所有观测数据及跨断裂GPS剖面观测数据作为约束,用Smith 3-D体力模型反演了海原断裂带断层滑动速率和断层闭锁深度．从西到东断裂共分为5段,采用遗传算法拟合GPS水平运动速度场,拟合残差均方根为1.1mm/a.反演结果为:毛毛山断裂左旋走滑运动速率为3.5mm/a,闭锁深度为22.0km;老虎山断裂左旋走滑速率为6.5mm/a,闭锁深度为１10.3km;海原断裂带西段、中段和东段的滑动速率依次为4.5mm/a、5.6mm/a和5.5mm/a,闭锁深度依次为8.4km、3.6km和4.3km．表明毛毛山断裂左旋走滑运动速率小,闭锁深度大,有利于应变能的积累,使得该断裂及附近地区存在发生强震的背景． 相似文献
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在阿尔金构造系中,阿尔金走滑断裂具有逆冲分量。文中将阿尔金构造系的逆冲活动分为西、中、东3段描述。西段从阿依耐克至车尔臣河河口,阿尔金南缘断裂具有逆冲活动迹象,在山前发育了规模较小的逆冲断层,有较新的地貌面被错动;中段从车尔臣河河口至拉配泉一带,在阿尔金山北缘发育大规模的逆冲断层,有较新的地貌面被错动;东段从拉配泉至宽滩山,逆冲断层有2种形式,此段阿尔金北缘断裂有逆冲分量,同时在阿尔金山北缘及山前冲洪积扇上发育逆冲断裂。自晚更新世中晚期以来,中段及东段逆冲速率<2mm/a。中段西部江尕拉萨依地区自16kaBP以来逆冲速率约为0.33mm/a,中部米兰桥一带自32kaBP以来的逆冲速率约为1.42mm/a。东段最大的逆冲速率在近中部的团结乡,自约5.31kaBP以来达到约1.81mm/a,向东西两端有减小的趋势,在西部柳城子自约72.36kaBP以来的逆冲速率为0.57mm/a,而东端的红柳沟自约8.99kaBP以来仅为0.05mm/a。团结乡地区约自19kaBP以来,逆冲活动有增强的趋势 相似文献
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以"中国地壳运动观测网络"区域站在海原断裂带附近的所有观测数据及跨断裂GPS剖面观测数据作为约束,用Smith 3-D体力模型反演了海原断裂带断层滑动速率和断层闭锁深度.从西到东断裂共分为5段,采用遗传算法拟合GPS水平运动速度场,拟合残差均方根为1.1 mm/a.反演结果为:毛毛山断裂左旋走滑运动速率为3.5 mm/a,闭锁深度为22.0km;老虎山断裂左旋走滑速率为6.5 mm/a,闭锁深度为10.3 km;海原断裂带西段、中段和东段的滑动速率依次为4.5 mm/a、5.6 mm/a和5.5 mm/a,闭锁深度依次为8.4 km、3.6km和4.3 km.表明毛毛山断裂左旋走滑运动速率小,闭锁深度大,有利于应变能的积累,使得该断裂及附近地区存在发生强震的背景. 相似文献
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阿尔金断裂带晚第四纪左旋走滑速率及其构造运动转换模式讨论 总被引：35，自引：2，他引：35
徐锡伟 P.Tapponnier J.Van Der Woerd F.J.Ryerson 王峰 郑荣章 陈文彬 马文涛 于贵华 陈桂华 A.S.Meriaux 《中国科学D辑》2003,33(10):967-974
在高分辨率SPOT卫星数字影像和大比例尺航片处理、断错地貌制图、野外核实与位移测量基础上, 利用宇宙成因核素(10Be, 26Al)、碳十四(14C)和热释光(TL)等多种测年手段, 厘定了各断错地貌面的形成年龄, 得到了阿尔金断裂带不同段落全新世左旋走滑速率: 阿克赛以西的中、西段左旋走滑速率可达(17.5±2) mm/a, 肃北-石包城段为(11±3.5) mm/a左右, 疏勒河口段减少到(4.8±1) mm/a左右, 东端宽滩山段仅约(2.2±0.2) mm/a, 左旋走滑速率突变点位于阿尔金断裂带中东段存在分支活动逆断层向南东扩展的肃北、石包城和疏勒河等三联点上. 矢量分析表明, 三联点东、西两侧左旋滑动速率的减少量转换成了阿尔金断裂带中东段南盘北西向活动逆断层上的地壳缩短和上盘推覆体抬升, 形成了党河南山、大雪山、祁连山等条块山地. 因此, 青藏高原北部物质向东挤出的速率和幅度是有限的, 符合“叠瓦状逆冲转换——有限挤出模型”. 相似文献
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四川西部的理塘—巴塘地区以近SN向的断裂构造为主,并发育 1组NNE和NW向的共轭剪切破裂带。文中在详细的TM卫片和航空照片判译的基础上,以活动构造地貌学为主线,重点解析了该地区断裂构造晚更新世—全新世以来活动的表现形式,确定近SN向的金沙江断裂带晚第四纪以来的近EW向的缩短速率为 2~3mm/a,NNE向巴塘断裂的右旋水平滑动平均速率为1. 3~2. 7mm/a,NW向理塘断裂的左旋水平滑动平均速率为 2 .6~4. 4mm/a。结合地球物理场、震源机制解、GPS测量等资料,分析了该地区现今地壳运动的总体态势及其所导致的块体运移规律,指出 1989年巴塘 6 .7级震群的成因,是由于NNE向巴塘断裂和NW向理塘断裂共轭剪切所派生的近EW向正断层的张性破裂所致,揭示了一个挤压构造环境内正断层发震的典型震例 相似文献
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THE SLIP RATE AND PALEOEARTHQUAKES OF THE YUMEN FAULT IN THE NORTHERN QILIAN MOUNTAINS SINCE THE LATE PLEISTOCENE 
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下载免费PDF全文 LI An WANG Xiao-xian ZHANG Shi-min CHEN Zhi-dan LIU Rui ZHAO Jun-xiang L&# Yan-wu 《地震地质》2016,38(4):897-910
The Yumen Fault lies on the west segment of the north Qilian Fault belt and adjacent to the Altyn-Tagh Fault,in the north margin of the Tibet Plateau.The tectonic location of the Yumen fault is special,and the fault is the evidence of recent activity of the northward growth of Tibetan plateau.In recent twenty years,many researches show the activity of the Yumen Fault became stronger from the early Pleistocene to the Holocene.Because the Yumen Fault is a new active fault and fold belt in the Qilian orogenic belt in the north margin of the Tibet Plateau,it is important to ascertain its slip rate and the recurrence interval of paleoearthquakes since the Late Pleistocene.Using the satellite image interpretation of the Beida river terrace,the GPS measurement of alluvial fans in front of the Yumen Fault and the trench excavation on the fault scarps,two conclusions are obtained in this paper.(1) The vertical slip rate of the Yumen Fault is about 0.41~0.48mm/a in the Holocene and about 0.24~0.30mm/a in the last stage of the late Pleistocene.(2) Since the Holocene epoch,four paleoearthquakes,which happened respectively in 6.12~10.53ka,3.6~5.38ka,1.64~1.93ka and 0.63~1.64ka,ruptured the surface scarps of the Yumen Fault.Overall,the recurrence interval of the paleoseismic events shortens gradually and the activity of the Yumen Fault becomes stronger since the Holocene.Anther characteristic is that every paleoearthquake probably ruptured multiple fault scarps at the same time. 相似文献
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THE TECTONIC ACTIVITY CHARACTERISTICS OF AWANCANG FAULT IN THE LATE QUATERNARY,THE SUB-STRAND OF THE EASTERN KUNLUN FAULT 下载免费PDF全文
下载免费PDF全文 It is well known that the slip rate of Kunlun Fault descends at the east segment, but little known about the Awancang Fault and its role in strain partitioning with Kunlun Fault. Whether the sub-strand(Awancang Fault) can rupture simultaneously with Kunlun Fault remains unknown. Based on field investigations, aerial-photo morphological analysis, topographic surveys and 14C dating of alluvial surfaces, we used displaced terrace risers to estimate geological slip rates along the Awancang Fault, which lies on the western margin of the Ruoergai Basin and the eastern edge of the Tibetan plateau, the results indicate that the slip rate is 3mm/a in the middle Holocene, similar to the reduced value of the Kunlun Fault. The fault consists of two segments with strike N50° W, located at distance about 16km, and converged to single stand to the SE direction. Our results demonstrate that the Awancang fault zone is predominantly left-lateral with a small amount of northeast-verging thrust component. The slip rates decrease sharply about 4mm/a from west to east between the intersection zone of the Awancang Fault and Kunlun Fault. Together with our previous trenching results on the Kunlun Fault, the comparison with slip rates at the Kunlun fault zone suggests that the Awancang fault zone has an important role in strain partitioning for east extension of Kunlun Fault in eastern Tibet. At the same time, the 15km long surface rupture zone of the southeast segment was found at the Awancang Fault. By dating the latest faulted geomorphologic surface, the last event may be since the 1766±54 Cal a BP. Through analysis of the trench, there are four paleoearthquake events identified recurring in situ on the Awancang Fault and the latest event is since (850±30)a BP. The slip rate of the Awancang Fault is almost equivalent to the descending value of the eastern part of the east Kunlun Fault, which can well explain the slip rate decreasing of the eastern part of the east Kunlun Fault(the Maqin-Maqu segment)and the characteristics of the structure dynamics of the eastern edge of the Tibet Plateau. The falling slip rate gradient of the eastern Kunlun Fault corresponds to the geometric characteristic. It is the Awancang Fault, the strand of the East Kunlun Fault that accommodates the strain distribution of the eastward extension of the east Kunlun Fault. This study is helpful to seismic hazard assessment and understanding the deformation mechanism in eastern Tibet. 相似文献
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The two mainstream deformation models of the Tibet plateau are continental escape model and crustal thickening model, the former suggests that the NW-trending Karakoram Fault, Gyaring Co Fault, Beng Co Fault and the Jiali Fault as the Karakoram-Jiali fault zone is the southern border belt and that the dextral strike-slip rate is estimated as up to 10~20mm/yr. However, research results in recent years show that the slip rates along those faults are significantly less than earlier estimates. Taylor et al. (2003)suggest that the conjugate strike-slip faults control the active deformation in the central Tibet.
The lack of research on the slip behavior of the NE-trending faults in the central Tibet Plateau constrains our understanding of the central Tibet deformation model. Thus, we choose the NE-direction Qixiang Co Fault located at the north of the Gyaring Co Fault as research object. Based on the interpretation of satellite images, we found several faulted geomorphic sites. Using RTK-GPS ground control point and unmanned aerial vehicle (UAV)topographic surveying, we obtained less than 10cm/pix-resolution digital elevation model (DEM)in the Yaqu town site. We used the LaDiCaoz_v2.1 software to automatically extract the left-lateral offset of the largest gully on the terrace T2 surface, which is (21.3±7.1)m, and the vertical dislocation of the scarp on the terrace T2 surface, which is (0.9±0.1)m. The age of both U-series dating samples on the terrace T2 is (4.98±0.17)ka and (5.98±0.07)ka, respectively. The Holocene left-lateral slip rate along Qixiang Co Fault is (3.56±1.19)mm/a and the vertical slip rate is (0.15±0.02)mm/a. The kinematic characteristics of the sinistral strike-slip with normal slip coincide with the eastward motion of the central Tibet plateau, and its magnitude is in agreement with its conjugate Gyaring Co Fault, suggesting that the deformation pattern of the central Tibetan plateau complies with the conjugate strike-slip faults mode. 相似文献
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以柴达木盆地新构造运动发生的期次、黄河兰州谷地出现的突出构造事件、阿尔金断裂带第四纪所经历的大运动阶段、攀西裂谷区新构造运动分期、北京地区南段新构造运动波动、全国一些地区断裂活动时序等为例证,再次证明了第四纪以来中国大陆地壳活动具有明显的时段性,４次强烈的构造活动分别发生在上新世末至早更新世初、早更新世中晚期、中更新世中晚期和全新世。其中,以中更新世中晚期地壳活动强度最大、波及范围最广 相似文献
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LATE QUATERNARY ACTIVITY OF THE CENTRAL SEGMENT OF THE DARI FAULT AND RESTUDY OF THE SURFACE RUPTURE ZONE OF THE 1947 M73/4 DARI EARTHQUAKE,QINGHAI PROVINCE 下载免费PDF全文
下载免费PDF全文 Bayan Hara Block is one of the most representative active blocks resulting from the lateral extrusion of Tibet Plateau since the Cenozoic. Its southern and northern boundary faults are characterized by typical strike-slip shear deformation. Its eastern boundary is blocked by the Yangze block and its horizontal movement is transformed into the vertical movement of the Longmen Shan tectonic belt, leading to the uplift of the Longmen Shan Mountains and forming a grand geomorphic barrier on the eastern margin of the Tibet Plateau. A series of large earthquakes occurred along the boundary faults of the Bayan Hara Block in the past twenty years, which have attracted attention of many scholars. At present, the related studies of active tectonics on Bayan Hara Block are mainly concentrated on the boundary faults, such as Yushu-Ganzi-Xianshuihe Fault, East Kunlun Fault and Longmen Shan Fault. However, there are also some large faults inside the block, which not only have late Quaternary activity, but also have tectonic conditions to produce strong earthquake. These faults divide the Bayan Hara Block into some secondary blocks, and may play important roles in the kinematics and dynamics mechanism of the Bayan Hara Block, or even the eastern margin of the Tibet Plateau. The Dari Fault is one of the left-lateral strike-slip faults in the Bayan Hara Block. The Dari Fault starts at the eastern pass of the Kunlun Mountains, extends eastward through the south of Yalazela, Yeniugou and Keshoutan, the fault strike turns to NNE direction at Angcanggou, then turns to NE direction again at Moba town, Qinghai Province, and the fault ends near Nanmuda town, Sichuan Province, with a total length of more than 500km. The fault has been considered to be a late Quaternary active fault and the 1947 M73/4 Dari earthquake was produced by its middle segment. But studies on the late Quaternary activity of the Dari Fault are still weak. The previous research mainly focused on the investigation of the surface rupture and damages of the 1947 M73/4 Dari earthquake. However, there were different opinions about the scale of the M73/4 earthquake surface rupture zone. Dai Hua-guang(1983)thought that the surface rupture of the earthquake was about 150km long, but Qinghai Earthquake Agency(1984) believed that the length of surface rupture zone was only 58km. Based on interpretation of high-resolution images and field investigations, in this paper, we studied the late Quaternary activity of the Dari Fault and the surface rupture zone of the 1947 Dari earthquake. Late Quaternary activity in the central segment of the Dari Fault is particularly significant. A series of linear tectonic landforms, such as fault trough valley, fault scarps, fault springs and gully offsets, etc. are developed along the Dari Fault. And the surface rupture zone of the 1947 Dari earthquake is still relatively well preserved. We conducted a follow-up field investigation for the surface rupture zone of the 1947 Dari earthquake and found that the surface rupture related to the Dari earthquake starts at Longgen village in Moba town, and ends near the northwest of the Yilonggounao in Jianshe town, with a length of about 70km. The surface rupture is primarily characterized by scarps, compressional ridges, pull-apart basins, landslides, cleavage, and the coseismic offset is about 2~4m determined by a series of offset gullies. The surface rupture zone extends to the northwest of Yilonggounao and becomes ambiguous. It is mainly characterized by a series of linear fault springs along the surface rupture zone. Therefore, we suggest that the surface rupture zone of the 1947 Dari earthquake ends at the northwest of Yilonggounao. In summary, the central segment of the Dari Fault can be characterized by strong late Quaternary activity, and the surface rupture zone of the 1947 Dari earthquake is about 70km long. 相似文献
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阿拉善地块南缘发育了由5条走向近EW、向西收敛、向东撒开的断裂组成的断裂束,每条断裂长度一般>100km,控制第四纪盆地呈EW向长条状展布,卫片上线性影像清晰,晚第四纪以来表现出左旋走滑活动的特点。断裂束西段的金塔南山断裂与阿尔金断裂带东段的宽滩山段趋于交会,并与文殊山构造隆起之间构成构造转换关系。分析认为金塔南山断裂以及整个阿拉善南缘断裂束是阿尔金断裂左旋运动的东延部分,断裂束在平面上“帚状”的、向东撒开的构造样式有利于走滑运动量的分解、消减和吸收,符合走滑断裂末端的构造特点。阿拉善南缘断裂束的左旋走滑活动有可能是阿尔金断裂带进一步向东扩展的结果,其时代可能发生于早更新世末—中更新世初 相似文献