共查询到19条相似文献，搜索用时 140 毫秒
1.
美姑地区位于扬子陆块西南缘四川断块西南部,西邻康滇地轴断块,南东接上扬子断块.因此该区域内地质构造复杂.深入研究该地区的叠加构造特征、演化过程,为美姑河流域梯级水电开发提供可靠的地质资料非常有意义.研究表明,该区域主要发育了SN、NE、NW三个方向的叠加构造体系,这三个方向的构造分别形成于喜马拉雅造山期的三个阶段,明确了各个构造体系之间的演化序列. 相似文献
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龙门山活动构造带位于青藏高原断块区巴颜喀喇断块与华南断块区四川断块之间,是青藏高原断块区东部边界构造带中段的一条北东向挤压推覆构造带,它南接川滇南北向构造带,北为岷山-西海固南北向构造带。与后二者历史上均发生过多次7~8级地震不同,龙门山构造带历史地震活动强度却相对较低,只发生过6~612级地震,汶川8.0级地震即发生在青藏高原断块区东部边界构造带中段这一历史地震活动水平相对较低的构造段。 相似文献
3.
李玶院士是新中国成立后最早从事地震构造研究的地球科学家。生于1924年3月20日,祖籍湖北大悟县。1943年考入重庆国立中央大学地质系学习,1947年大学毕业后留校任教。1949年解放后百业待兴,先生与肖楠森教授一起协助南京市政府从事工程地质和水文地质方面的工作,1950年深感这方面人才的急需,先生上书教育部建议在南京大学地质系创办工程水文地质专业,获批准后即开办,为我国早期工程建设培养了大量人才。1954年调哈尔滨军事工程学院任教,在苏联专家的指导下讲授军事工程地质学,并从事沿海地下工程选址。1959年调入北京,先后在中国科学院地质研究所、中国地震局地质研究所从事地震构造、工程场地区域地壳稳定性和地震安全性评价工作至今,同时培养了一批学有所成的硕士和博士。20世纪50年代末至80年代初,由于工程建设的需要,先生作为长江三峡工程地震地质工作的负责人,多次在该地区围绕三峡坝址区开展大范围的野外地质调查和航空目测。通过细致的野外工作,发现了该区断块结构的特点,以及围绕断块的活动断裂带与强震的成因联系,认为完整的断块内部不会发生强震。三峡坝址就位于该区的黄陵断块内,故其未来受地震的影响,主要来自断块外围大断裂带的活 相似文献
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长江三峡地区地壳形变特征及其构造意义 总被引：5，自引：1，他引：5
本文讨论了三峡地区地壳形变特征,认为黄陵断块相对于周缘的差异性运动是存在的,最大年速率可达5—10毫米。跨断层的短水准结果以继承性断层活动为主,年速率在毫米级。水平形变网揭示仙女山断裂带近年来表现为左旋压扭性,天阳坪断裂带以右旋滑动为主 相似文献
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滇东南楔形构造区的区域断裂几何结构突出地表现为半棋盘格式。具有区域应力场分界意义的红河断裂,把其它几条断裂限制在其北部,并与小江断裂带构成第一级的半断块。构造区内,曲江断裂被李浩寨断裂限制在其西侧;后者与异龙湖断裂交汇于建水盆地中;建水断裂把黑泥地断裂限制于其东,并与李浩寨断裂构成建水盆地右阶拉分岩桥区,向南终止于山花。 深部构造、区域形变及断裂活动表明该构造区是一个断块挤压隆起构造区。最后,对楔形构造区的地震活动与挤压隆起断块运动的关系作了简要的分析 相似文献
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安徽省地处华北断块、下扬子断块及秦岭一大别山断块上,郯庐大断裂纵贯南北,构造条件比较复杂,历史上曾经发生多次5级以上地震。合肥遥测台网建于20世纪80年代,建成后曾记录到了省内数次有感以上地震。经过“九五”数字化改造后,目前包括10个子台,主要分布在以合肥市为中心的方圆约200km范围内,全部采用无线传输方式,建成之初就记录到了 相似文献
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塔里木盆地中央隆起带中、西段及邻区中、下寒武统广泛发育盐岩层系.本文通过地震和钻井资料综合解释和分析,发现这套盐岩层系形成时代老,埋藏深度大,流动聚集幅度较小,厚度分布不均匀,它们作为区域滑脱层对该区盐上古生界构造变形起着重要控制作用,形成一系列含油气圈闭构造.同时,由于寒武系盐岩层系提供的优质盖层和封闭条件,大大提升了该区盐下震旦-寒武系目的层系的油气勘探价值.研究表明,该区中、下寒武统盐相关构造主要包括盐枕构造、盐滚构造、盐(上)背斜构造、盐刺穿构造、盐拱-盐上断块构造组合、基底断裂-盐背斜构造组合、基底断块-盐丘构造组合、盐岩滑脱-断层相关褶皱组合、基底断块-盐拱-盐上叠瓦冲断组合.这些盐相关构造的形成演化和变形机理主要受控于基底断裂作用、挤压缩短作用、塑性流动聚集作用、上覆层系重力作用和盐上层断裂滑脱作用等,盐相关构造主要沿基底断裂或断块构造带成排成带分布. 相似文献
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在华北断块东南边沿,有一条划分两大区域断块的深大断裂,即响水口——嘉山地壳断裂带,对该断裂构造的地质研究工作较多,但对其地震活动性的研究却很少。本文仅对其紧靠郯庐深大断裂的交切三角地带——洪泽湖湖域附近作一探讨。洪泽湖地区处洪泽湖断裂上,该断裂是响水口——嘉山地壳断裂带的西端,长约103公里。面积约为七、八千平方公里。见(图1)。从已有的钻探和物探资料分析,该断裂带在重力上表现为一条自嘉山经洪泽湖到响水口的北东向梯度带。在嘉山附近将郯庐断裂带切割。梯度带两侧的钻孔资料表明,胶辽断块和扬子断块以其分界,是一 相似文献
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用DDA模拟华北地区的无震断层滑动和断块形变 总被引：6，自引：0，他引：6
华北地区的地质构造具有典型的断块系统特征。用非连续形变分析（DDA）方法模拟了该地区的长期形变，包括无震断层滑动和断块形变。通过模拟我们发现：（1）断层沿不同方向的滑动通常与ENE－WSW向的区域构造挤压一致。（2）如果沿主要活动断层的平均无震滑动速度与跨断层大地测量观测的结果一样是每年零点几毫米的量级，那么断块内的典型应变速率是10^-8/a或更小量级，所以一些小区域的观测报告所得的应变率10^-6/a就不能代表该地区的形变速率。（3）对一条断层，由相邻断块内刚体旋转引起的断层滑动方向可能与区域构造挤压引起的滑动方向相反。但由于由构造挤压引起的滑动量级远大于由断块旋转引起的断层滑动，因此，一般来讲，断层滑动图像总体上与这一地区构造挤压方向一致，也就是说，由区域挤压引起的滑动控制了整个滑动情况。（4）根据（3），某些观测到的与ENE构造挤压方向相反的滑动可能是由某些更为局部化的因素引起的，没有构造意义。 相似文献
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岷山断块位于中国南北强震构造带的中段, 区域地质构造复杂, 活动断裂众多, 强震频发。 4条不同走向的活动断裂NE向龙门山构造带的茂汶断裂、 NWW向东昆仑断裂带的塔藏断裂、 近NS向的岷江断裂和NNW—NS向的虎牙断裂构成岷山断块的南北西东边界。 638—2017年该区域共发生了10次6级以上破坏性地震, 2017年九寨沟7.0级地震就是其中之一。 结合区域构造背景, 对岷山断块所发生的6级以上地震的发震构造特征、 地震活动特性进行归纳总结, 综合分析该区域地震地质特征及地震危险性, 得出以下认识: ① 地震分布空间分区特征显著, 破坏性强震发震构造多为活动性较强的岷山断块东西边界断裂, 震中位置多位于两组或多组活动断裂构造的交会或穿切部位; ② 地震分布时间特征表现为随着时间发展具有迁移回返和原地复发性等特点; ③ 岷山断块东西边界断裂破坏性地震的发生具有一定的时间关联性, 东边界虎牙断裂1973—2017年的地震序列为西边界岷江断裂1933—1960年地震序列约40年后的地震构造响应; ④ 未来岷山断块仍应是继续关注的强震潜在危险区, 岷江断裂中北段的强震潜在危险区是近期值得深入研究的地区之一。 相似文献
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南天山及塔里木北缘构造带位于帕米尔地区东北侧,地震活动强烈。文中通过地质构造剖面、深部探测资料和地震震源机制解资料,综合研究了该区的地震构造模型。结果认为,该区的构造活动主要表现为天山地块逆冲于塔里木地块之上。天山构造系统包括迈丹断裂及其前缘推覆构造;塔里木构造系统包括深部的塔里木北缘断裂、基底共轭断层和浅部的推覆构造。塔里木北缘断裂是发育于塔里木地壳内部的高角度断裂,其形成原因在于塔里木和天山构造变形方向的差异。塔里木北缘断裂为研究区大地震的主要发震构造,天山推覆构造和塔里木基底断裂系统均具有不同性质的中强地震发震能力 相似文献
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ACTIVE FAULTS AND THEIR FORMATION MECHANISM IN THE EAST SEGMENT OF QIULITAGE ANTICLINE BELT,KUQA DEPRESSION 
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下载免费PDF全文 LI Sheng-qiang ZHANG Ling YANG Xiao-ping HUANG Wei-liang HUANG Xiong-nan YANG Hai-bo 《地震地质》2016,38(2):223-239
Based on geological and geomorphologic characteristics of the surface faults acquired by field investigations and subsurface structure from petroleum seismic profiles, this paper analyzes the distribution, activity and formation mechanism of the surface faults in the east segment of Qiulitage anticline belt which lies east of the Yanshuigou River and consists of two sub-anticlines:Kuchetawu anticline and east Qiulitage anticline. The fault lying in the core of Kuchetawu anticline is an extension branch of the detachment fault developed in Paleogene salt layer, and evidence shows it is a late Pleistocene fault. The faults developed in the fold hinge in front of the Kuchetawu anticline in a parallel group and having a discontinuous distribution are fold-accommodation faults controlled by local compressive stress. However, trenching confirms that these fold-accommodation faults have been active since the late Holocene and have recorded part of paleoearthquakes in the active folding zone. The fault developed in the south limb near the core of eastern Qiulitage anticline is a low-angle thrust fault, likely a branch of the upper ramp which controls the development of the eastern Qiulitage anticline. The faults lying in the south limb of eastern Qiulitage anticline are shear-thrust faults, which are developed in the steeply dipping frontal limb of the fault-propagation folds, and also characterized by group occurrence and discontinuous distribution. Several fault outcrops are discovered near Gekuluke, in which the Holocene diluvial fans are dislocated by these faults, and trench shows they have recorded several paleoearthquakes. The surface anticlines of rapid growth and associated accommodation faults are the manifestations of the deep faults that experienced complex folding deformation and propagated upward to the near surface, serving as an indicator of faulting at depth. The fold-accommodation faults are merely local deformation during the folding process, which are indirectly related with the deep faults that control the growth of folds. The displacement and slip rate of these surface faults cannot match the kinematics parameters of the deeper fault, which controls the development of the active folding. However, these active fold-accommodation faults can partly record paleoearthquakes taking place in the active folding zone. 相似文献
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The processes and rates of the weathering denudation of the bare crystalline rock are important problems in the field of geosciences[1—6]. Essentially, the weathering denudation process is the process of rock destruction and transportation. In different … 相似文献
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以八钢—石化隐伏断裂为例,介绍了在乌鲁木齐地区第四系较厚的河流相卵砾石覆盖层中利用浅层人工地震探测隐伏活动断裂的具体方法。首先进行观测系统参数的确定,其次实施多次覆盖的人工地震探测,从而获得较好的多层反射界面剖面,在此基础上结合相关资料进行地质解译,最后通过钻孔联合剖面验证。分析结果表明,八钢—石化隐伏断裂为隐伏的逆断层—背斜构造,宽度达150~300 m,主断层位于背斜北侧,有2条,为倾向S或SE的逆断层,错断了中更新统—上更新统砾石层,上盘形成背斜构造,在背斜南翼发育次级逆断层或正断层,主逆断层带的总垂直位移为21~23 m。 相似文献
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P wave velocity structure of upper and middle crust beneath the Three Gorges reservoir dam and adjacent regions 总被引：3，自引：0，他引：3
The three-dimensional P wave velocity structures of upper and middle crust beneath the Three Gorges reservoir dam and adjacent
regions were reconstructed by means of the seismic tomography, using the absolute P-arrivals from the events observed by the
Three Gorges seismic network. Our preliminary study of the deep structure shows: (1) the lithology of the Huangling anticline,
integral and highly solidified, exhibits a uniformity. Down to a depth of 20 km, the Huangling anticline still shows high-velocity
anomalies. Note that the characteristics of the velocity images with the different depths are not the same; (2) the depth
of the sedimentary rocks beneath the entire Zigui basin is not constant, which is less than 6 km; (3) the top boundary of
the crystalline basement varies from 0 to 7 km, whereas the bottom one between 14 and 16 km; (4) the partially molten substances
of the upper mantle are located in the Badong-Zigui and its adjacent regions as well as nearby Peishi area. The development
and evolution of the current tectonics are associated with the cooling and solidifying process of the molten substances within
the upper mantle; (5) the different velocity structures of the deep crust in both east and west side of the Jiuwanxi fault
are to be investigated in order to understand the origin of gravitational gradient zone in the Three Gorge areas; and (6)
the velocities within the upper crust would be affected by reservoir water permeability.
Supported by National Natural Science Foundation of China (Grant No. 40574039), National Key Technology R& D Program (Grant
No. 2008BAC38B02) 相似文献
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西南天山-塔里木盆地结合带浅深构造关系 ——深地震反射剖面的初步揭露 总被引：4，自引：0，他引：4
盆山结合部的浅-深结构样式是进行陆内造山动力学研究与讨论的重要依据.2007年,在喀什东的天山与塔里木盆地之间的过渡带上,完成了一条近南北向的长度为121 km的主动源深地震反射剖面,显示出盆山结合部现今地壳尺度的构造格架.剖面南部呈现出10~12 km巨厚的沉积盖层,沉积盖层内发育滑脱断层;盆山结合部多排隆起构造以及天山山前上地壳显现出向北倾斜的断裂与地表地质观察吻合;盆山结合带展现出滑脱与逆冲推覆构造相关的断层褶皱;与塔里木盆地稳定沉积层相比,在南天山浅、中层地层受到强烈的变形改造,导致地层比较破碎,反射变弱、连续性较差;时间剖面上可以追踪到比较连续的Moho反射,从南向北有加深的趋势.深地震反射剖面揭露出的西南天山与塔里木盆地的这些浅-深构造,展现出塔里木盆地盖层向南天山滑脱与南天山向塔里木盆地逆冲推覆的特征,反映出陆内汇聚下的盆山耦合关系. 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