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苏锡常断裂是长三角地区一条重要的NW向隐伏断裂。文中利用浅层地震勘探和钻孔联合剖面探测方法,对苏锡常断裂的展布特征及其第四纪活动性进行了系统研究。浅层地震勘探成果表明:在苏州地区,苏锡常断裂南支整体倾向NE,倾角约60°,基岩断距3～5m,以正断活动为主;在常州地区,苏锡常断裂北支以正断活动为主,倾向S,倾角约55°～70°,基岩断距4～12m。在地震剖面上,苏锡常断裂的各个断点都以断错基岩面为特征,第四系内部层位断错不明显。苏州东桥镇场地上,苏锡常断裂南支断错的最新地层为下更新统上部;常州朝阳路场地上,苏锡常断裂北支断错的最新地层为中更新统底部。综合判断苏锡常断裂的最新活动时代为中更新世早期。苏锡常断裂在前第四纪总体以左旋正断活动为主,早更新世后则在多处转变为左旋逆断性质,第四纪内部层位断错量约3m,判断苏锡常断裂最大潜在地震震级为6. 0级。 相似文献
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昌平-丰南断裂是根据卫星遥感图像解译发现的一条隐伏活动断层，是NWW向张家口-蓬莱断裂带中规模最大的断裂，为进一步调查确认断裂的存在、空间位置、性质和断裂构造特征，并重新厘定其活动性，在卫星遥感影像解译断裂大体空间位置的基础上，布设了2条浅层地震勘探测线，对昌平-丰南断裂进行了高分辨率地震勘探，获得了测线控制范围内地下结构和断裂构造的清晰成像。结果表明，昌平-丰南断是一条倾向S、走向NWW的走滑正断层，浅层地震剖面揭示断层上断点埋深80~100 m，断错了上更新统底界，结合测线附近钻孔资料推测其最新活动时代为晚更新世。 相似文献
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《华北地震科学》2018,(4)
依据盆地第四系沉积特点,结合高密度、CSAMT(可控源音频大地电磁)、浅层地震及钻孔磁化率探测结果,剖析隐伏断裂在盆地的几何形态特征及活动性。结果表明:延矾盆地北缘断裂南段(隐伏端)沿窑湾村-桑园南堡村展布,由2条SE倾的阶梯状正断层组成,切割第四系上更新统泥河湾组地层,上断点埋深40m,断距约35m;断裂在早-中更新世有过活动,晚更新世断裂活动性较强,全新世以后断裂活动性具逐渐减弱趋势;施庄断裂北隐伏段经施庄向SE145°方向展布,切割第四系泥河湾组地层,上断点埋深70m,断裂早-中更新世有过活动,晚更新世断裂活动性较强。综合分析认为,延怀盆地隐伏断裂在晚更新世时期活动性强,而全新世以来,各断裂活动性减弱。 相似文献
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松辽盆地北部反转构造的几何特征、变形机制及其地震地质意义——以大安-德都断裂为例 总被引：4，自引：2，他引：2
松辽盆地北部发育的中-新生代反转构造代表着盆地继伸展裂陷阶段、热冷却拗陷阶段之后的第3个构造演化阶段。系统收集了布设在覆盖大安-德都断裂及其附近的14个3维地震工区,30条区域地震反射大剖面,在此基础上准确追踪解释了T06、T1、T11、T2、T3、T4、T5等7个地震反射层位。同时基于52口钻孔的资料对重点反射层的地质年代进行了重新厘定,分析了不同时期断层展布特征及分布规律,重点就松辽盆地中新生代反转构造的几何学形态、变形特征与机制进行了研究。研究结果认为,该反转构造为大安-德都断裂在中生代末期和新生代早期的主要变形模式,符合"逆断层-褶皱"构造的几何形态和变形机制。松辽盆地内部的构造变形主要集中在该构造反转带上。此外,重点选择了2条典型剖面开展了野外实验性浅层人工地震勘探。根据勘探结果并结合该地区第四纪地层厚度分析认为,广泛发育在背斜顶部且断错T06界面的小断裂可能代表了大安-德都断裂强变形带的最新活动性,勘探剖面揭示的上断点断错最年轻地层为中更新统,并据此初步判定该断裂最新活动时代可能为中更新世。此外,综合人工地震勘探结果、现代地震活动性和震源机制解研究结果认为,大安-德都断裂的"逆断层-褶皱"构造反转带最新的活动已明显影响到了近地表的反射层,清楚断错了早-中更新世地层,控制着断裂附近中强地震的发生,是松辽盆地内部或整个东北地区重要和典型的发震构造之一。 相似文献
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浅层人工地震勘探是探查城市隐伏活动断层最有效的手段之一,然而受近地表探测盲区和探测分辨率的限制,该方法难以获取活动断层超浅层上断点的准确埋深位置。地质雷达探测方法在一定程度上可弥补浅层人工地震勘探的不足。为探索浅层人工地震勘探和地质雷达探测的联合应用效果,分析其在城市隐伏活动断层探测中的应用潜力,选取河南省鹤壁市汤东断裂西支为研究对象,并在冯屯村和前交卸村分别开展联合探测,获取高信噪比的浅层人工地震反射剖面和地质雷达剖面。浅层人工地震勘探揭示的冯屯村处汤东断裂西支上断点埋深为60～70 m,地质雷达探测揭示的上断点埋深约为2.5 m,结合平均沉积速率推测汤东断裂西支在冯屯村的最新活动时代约为25 ka。浅层人工地震勘探揭示的前交卸村处汤东断裂西支上断点埋深为50～60 m,地质雷达探测揭示出汤东断裂西支在前交卸村处未造成近地表约10 m以内的地层断错。研究结果表明,在城市隐伏活动断层探测中,采用浅层人工地震勘探和地质雷达探测相结合的方法,不但可有效确定活动断层的位置,且可进一步约束活动断层上断点的准确埋深,有利于指导后期地震地质勘探中的探槽和钻孔布设。 相似文献
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RELOCATION OF THE BACKGROUND SEISMICITY AND INVESTIGATION ON THE BURIED ACTIVE FAULTS IN SOUTHEASTERN CHINA 
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下载免费PDF全文 ZHU Ai-lan XU Xi-wei REN Ye SUN Dong-jun WANG Peng YU Hai-ying SONG Xiu-qing LIU Fang 《地震地质》2017,39(1):67-80
Most of the regions in southeastern China are covered by thick Cenozoic sediments, or are the mountainous areas, so it is difficult to find and locate the active faults using the conventional geologic methods. The precisely relocated background seismicity in the seismically active region can be used to identify the buried active structure. In this paper, we investigated the relationship between regional tectonics and background seismicity, and interpreted the possible buried active faults in southeastern China using the relocated background seismicity. We relocated the background seismicity occurring in the region from 106°E to 122°E and from 22°N to 35°N between 1990 and 2014 using the doubble difference earthquake location algorithm. More than 51000 small earthquakes were relocated. In general, the relocated background seismicity corresponds well to the tectonics, showing the zonation features with typical seismicity pattern in each tectonic regime. It is observed that in the weakly active tectonic regime, the seismicity distributes dispersely or even scarcely, while in the strongly active tectonic region, the seismicity is highly clustered and organized to lineation pattern showing the same direction as the strike of the dominating fault zone. We interpreted the buried active faults using the lineation of seismicity. The inferred active faults are observed in the southeast coast region, the northwest Guangxi Province, the southeast boundary region of the Sichian Basin, and around the Huoshan Fault, many of which were not found by previous studies. The relocated hypocentral depth varies greatly in southeastern China. The shallowest earthquakes between 0 and 15km mainly distribute in the central region, indicating that the brittle deformation process only occurred in the upper crust, while the middle and lower crust are to be half-ductile and ductile deformation. There are earthquakes occurred in lower crust in the southeast coast region. The maximum depths distribute in the southeast boundary region of the Sichuan Basin, some are greater than 40km, indicating that the crust depth is larger than other places and the lower crust still sustains brittle deformation, which corresponds to the lower geothermal value and high crustal strength. 相似文献
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文中通过国内外隐伏活动构造研究发展历史回顾与最新研究动态的分析 ,提出了当前隐伏活动构造在浅部精细特征研究、深浅构造关系研究和高新技术手段运用等方面存在的不足和问题。为适应隐伏活动构造研究不断发展的需要 ,作者认为 ,以浅层物探、系列钻探和新年代研究为支点 ,开展多学科手段的综合定量研究是深化这一研究的基础 ,而进行隐伏活动构造的科学分类、准确定位和最新一期活动性研究是当前研究的主要目标 相似文献
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城市范围内直下型活动断裂突发错动产生的直下型大地震 ,直接威胁城市和人民生命财产的安全。城市活动断裂探测和地震危险性评价是为城市减灾服务的一项系统工程 ,也是活动构造研究面临的一项新的工作。这一工作的核心是要解决城市范围内的断裂定位、断裂最新活动、断裂的深部背景、断裂的地震危险性和地面错动危险性及减灾对策。为了更好地理解这一问题 ,作者用“有没有、活不活、深不深 ,震不震 ,错不错 ,好对策”这 6句话来表示其核心内容。文中对这些问题作了具体的说明 相似文献
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利用地震剖面研究夏垫断裂西南段的活动性 总被引：5，自引：1，他引：4
地震方法是针对厚覆盖区城市直下型活动断裂的一种不可替代的探测技术,对于不同的探测深度需采用不同的排列长度。为研究夏垫断裂在远离三河-平谷8.0级地震震源区的活动性,我们在该震源区SW方向约30km处开展了中浅层反射地震探测试验,并跨过中浅层地震探测到的夏垫断裂进行了浅层反射地震探测试验。浅层和中浅层地震探测的试验结果表明,在5m道间距的地震剖面上,在200m深度以下夏垫断裂得到了较好的反映,在该深度以上,该断裂反映不明显;在2m道间距的地震剖面上,夏垫断裂错断明显,但剖面上的最浅一组反射波(深度约30m)却没有发生明显错断。由此得出:距1679年三河-平谷8.0级地震震源位置SW方向约30km处,夏垫断裂的活动性减弱 相似文献
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SHALLOW STRUCTURE AND ACTIVITY CHARACTERISTICS OF THE ZHUYANGGUAN-XIAGUAN FAULT IN THE NANYANG BASIN
The Zhuyangguan-Xiaguan fault is a major fault in the Nanyang Basin. Together with the the Shangxian-Danfeng fault in the south and the Tieluzi fault in the north, it serves as the north boundary of the East Qingling Mountains, as well as the dividing line between North China and South China blocks. This work studied the spatial extension, activity and shallow structure of Zhuyangguan-Xiaguan Fault by combination of shallow seismic exploration of three profiles across the fault and a composite drilling cross-section data.
The anti-interference and high resolution shallow seismic reflection exploration method based on Vibseis techniques was used in the seismic survey. The results show the existence of the main fault and its southern branch. It can be determined that the the Zhuyangguan-Xiaguan fault is a NWW-trending normal fracture. The composite drilling cross-section reveals that the buried depth of the fault's up-breakpoint is about 17.6 to 20.5 meters and the latest active time is the late Middle Pleistocene.
As one of the major buried faults in the Nanyang Basin, the Zhuyangguan-Xiaguan fault has restricted the development of Nanyang City for a long time due to its unclear location and activity characteristics. The results of this study can provide geological and geophysical evidence for seismic risk assessment and site selection for the major lifeline projects in Nanyang City. 相似文献
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本文简介从新疆叶城至西藏狮泉河的大地电磁测深剖面．它北起塔里木盆地，横跨昆仑山脉和喀喇昆仑山脉地区到冈底斯西段，全长８００余公里．探测结果表明，不同测点的地壳内部有的有两个低阻层，有的则只有一个低阻层，壳内第１低阻层的埋藏深度约１０－３５ｋｍ，第２低阻层的埋藏深度约３０－６５ｋｍ。在南昆仑缝合带以南，壳内低阻层的埋藏深度有从南向北不断加深的趋势；而在其以北的壳内低阻层的埋藏深度则与此相反．上地幔第１低阻层的埋藏深度约在１００－１５０ｋｍ之间，第２低阻层的埋藏深度约在３５０－５５０ｋｍ之间． 相似文献
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NEW EVIDENCES FOR LATE QUATERNARY ACTIVITY IN THE SOUTHERN SEGMENT OF THE YISHU-TANGTOU FAULT,THE TAN-LU FAULT ZONE,AND ITS TECTONIC IMPLICATION 下载免费PDF全文
下载免费PDF全文 CAO Jun XU Han-gang RAN Yong-kang LIANG Ming-jian LEI Sheng-xue ZHANG Peng LI Li-mei GU Qin-ping ZHAO Qi-guang 《地震地质》2017,39(2):287-303
The Tan-Lu Fault Zone(TLFZ), a well-known lithosphere fault zone in eastern China, is a boundary tectonic belt of the secondary block within the North China plate, and its seismic risk has always been a focus problem. Previous studies were primarily conducted on the eastern graben faults of the Yishu segment where there are historical earthquake records, but the faults in western graben have seldom been involved. So, there has been no agreement about the activity of the western graben fault from the previous studies. This paper focuses on the activity of the two buried faults in the western graben along the southern segment of Yishu through combination of shallow seismic reflection profile and composite drilling section exploration.
Shallow seismic reflection profile reveals that the Tangwu-Gegou Fault(F4)only affects the top surface of Suqian Formation, therefore, the fault may be an early Quaternary fault. The Yishui-Tangtou Fault(F3)has displaced the upper Pleistocene series in the shallow seismic reflection profile, suggesting that the fault may be a late Pleistocene active fault. Drilling was implemented in Caiji Town and Lingcheng Town along the Yishui-Tangtou Fault(F3)respectively, and the result shows that the latest activity time of Yishui-Tangtou Fault(F3)is between(91.2±4.4)ka and(97.0±4.8)ka, therefore, the fault belongs to late Pleistocene active fault.
Combined with the latest research on the activity of other faults along TLFZ, both faults in eastern and western graben were active during the late Pleistocene in the southern segment of the Yishu fault zone, however, only the fault in eastern graben was active in the Holocene. This phenomenon is the tectonic response to the subduction of the Pacific and Philippine Sea Plate and collision between India and Asian Plate. The two late Quaternary active faults in the Yishu segment of TLFZ are deep faults and present different forms on the surface and in near surface according to studies of deep seismic reflection profile, seismic wave function and seismic relocation. Considering the tectonic structure of the southern segment of Yishu fault zone, the relationship between deep and shallow structures, and the impact of 1668 Tancheng earthquake(M=8(1/2)), the seismogenic ability of moderate-strong earthquake along the Yishui-Tangtou Fault(F3)can't be ignored. 相似文献
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成都平原的形成与演化 总被引：12，自引：0，他引：12
成都平原是位于青藏高原东南侧前缘的第四纪压陷盆地，东西两侧分别被龙泉山和龙门山所限。研究表明，成都平原的第四纪断陷作用从大邑－彭县－绵竹隐伏断裂和浦江－新津－成都－德阳断裂所夹的北东向断块的为民陷开始，然后向东西两侧扩展。不同断裂在不同时代的逆冲运动对成都平原的形成和演化起重要的制约作用。 相似文献
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THE RESEARCH OF THE SEISMOGENIC STRUCTURE OF THE LUSHAN EARTHQUAKE BASED ON THE SYNTHESIS OF THE DEEP SEISMIC DATA AND THE SURFACE TECTONIC DEFORMATION 下载免费PDF全文
下载免费PDF全文 WANG Lin ZHOU Qing-yun WANG Jun LI Wen-qiao ZHOU Lian-qing CHEN Han-lin SU Peng LIANG Peng 《地震地质》2016,38(2):458-476
The seismogenic structure of the Lushan earthquake has remained in suspensed until now. Several faults or tectonics, including basal slipping zone, unknown blind thrust fault and piedmont buried fault, etc, are all considered as the possible seismogenic structure. This paper tries to make some new insights into this unsolved problem. Firstly, based on the data collected from the dynamic seismic stations located on the southern segment of the Longmenshan fault deployed by the Institute of Earthquake Science from 2008 to 2009 and the result of the aftershock relocation and the location of the known faults on the surface, we analyze and interpret the deep structures. Secondly, based on the terrace deformation across the main earthquake zone obtained from the dirrerential GPS meaturement of topography along the Qingyijiang River, combining with the geological interpretation of the high resolution remote sensing image and the regional geological data, we analyze the surface tectonic deformation. Furthermore, we combined the data of the deep structure and the surface deformation above to construct tectonic deformation model and research the seismogenic structure of the Lushan earthquake. Preliminarily, we think that the deformation model of the Lushan earthquake is different from that of the northern thrust segment ruptured in the Wenchuan earthquake due to the dip angle of the fault plane. On the southern segment, the main deformation is the compression of the footwall due to the nearly vertical fault plane of the frontal fault, and the new active thrust faults formed in the footwall. While on the northern segment, the main deformation is the thrusting of the hanging wall due to the less steep fault plane of the central fault. An active anticline formed on the hanging wall of the new active thrust fault, and the terrace surface on this anticline have deformed evidently since the Quaterary, and the latest activity of this anticline caused the Lushan earthquake, so the newly formed active thrust fault is probably the seismogenic structure of the Lushan earthquake. Huge displacement or tectonic deformation has been accumulated on the fault segment curved towards southeast from the Daxi country to the Taiping town during a long time, and the release of the strain and the tectonic movement all concentrate on this fault segment. The Lushan earthquake is just one event during the whole process of tectonic evolution, and the newly formed active thrust faults in the footwall may still cause similar earthquake in the future. 相似文献
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华北西部许多第四系隐伏的断陷盆地,经人工地震探测发现在盆地边缘存在生长性主干大断裂。于大断裂附近隆起的山麓露头区,有时出露新活动断裂,二者性质似乎"相同"、产状近于平行。隐伏的主干大断裂发育的最晚时代(时代上限)与山麓活动断裂的形成时代接近,因此被认为是同一断裂系,其差异仅仅是出露与隐伏的不同。为此以内蒙古临河断陷盆地为例进行了实地野外观察与地震反射剖面解释,认为隐伏的主干断裂是自下向上发育的生长断裂,是地壳运动的产物,而山麓露头的活动断裂则是自上向下滑落,断裂的形成倾向于(主要)是重力因素。二者本质上毫无关系,不是一个断裂系,不能依据山麓活动断裂的特征来推导隐伏断裂的性状与活动性。 相似文献