共查询到19条相似文献，搜索用时 125 毫秒
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通过野外地质调查、浅层地震勘探和钻孔联合剖面探测等方法,对废黄河断裂的第四纪活动性进行了研究。浅层地震勘探结果表明,废黄河断裂由南北两条主干断裂组成,南支断裂倾向NE,北支断裂倾向SW,总体为一地堑形式,断裂宽度为1~2km。在地震剖面上,废黄河断裂的各个断点都是以断错基岩面为特征,并未断错第四系内部层位。钻孔联合剖面探测结果显示,废黄河断裂断错了中更新统层位,但未断错其顶面。在凤山一带发现1条废黄河断裂的次级断层出露,结合断层泥胶结程度、测年结果和地貌特征等判断,该断层最新活动为中更新世中期。综合以上研究工作成果,判断废黄河断裂早期为左旋活动,第四纪以来表现为张性活动,其最新活动时代为中更新世中期。受构造背景的控制,徐州地区发育的NW向断裂明显较相邻的鲁西南地区的NW向断裂活动性弱。 相似文献
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西宁市北川河西岸断层、湟水断层活动性的钻探研究 总被引：1，自引：0，他引：1
本文主要根据《西宁市活断层探测与地震危险性评价》项目中跨断层钻探工作的初步结果,对西宁盆地河谷区两条主要的目标断层——北川河西岸断层、湟水断层的活动性予以阐述。通过对断层两侧钻孔岩芯的地层对比及年代学研究结果,建立跨断层柱状剖面,获得各地层层序主要界面的形成时代,并取得如下认识:北川河西岸断层在畜牧研究所场地并未断错到第四系覆盖层,晚更新世以来断层没有活动;湟水断层在彭家寨镇场地未断开第四系覆盖层,晚更新世晚期(约2万年)以来断层没有活动。 相似文献
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乌鲁木齐城市活断层探测与地震危险性评价主要成果简介 总被引：2，自引：0，他引：2
以乌鲁木齐市建成区和规划区作为探测目标区,对区内的活动断层及其深部发震构造进行了系统的探测,对活动断层的危险性和危害性进行了初步评价。根据断层活动性鉴定,确定目标区内存在2组全新世活动断层,即王家沟断层组和九家湾断层组。前者为近EW向的北倾逆断层,后者为NE走向的北倾正断层。晚更新世活动断层为八钢-石化隐伏断层、西山断层、碗窑沟断层和白杨南沟断层。深部发震构造探测揭示出目标区所处的北天山山前薄皮推覆构造及其前缘逆断层-褶皱的清楚结构,结合流动地震观测和小震精确定位等,建立了目标区活动断层的发震构造模型。通过古地震探槽和地震活动性研究对目标区全新世活动断层和晚更新世活动断层的地震危险性进行了评价;并在此基础上对可能发生的直下型大地震所引起的强地震动进行了预测,对全新世活动断层可能产生的地表错动带和晚更新世活动断层可能引起的地表变形带进行了预测 相似文献
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辽宁省主要活动断层与地震活动特征分析 总被引：6，自引：1，他引：5
本文结合编制 1：100 万辽宁省地震构造图,分析了辽宁省近 20 年来地震构造环境相关研究成果,确定辽宁地区共有第四纪以来活动断裂 29 条：全新世断裂 1 条;晚更新世断裂 5 条;早、中更新世断裂 23 条。其中北东向晚更新世活动断裂和北西向全新世活动断裂为辽宁地区的主要控震、发震构造。北东向晚更新世活动断裂与北西向断裂交汇部位、海城河隐伏断裂的端点部位和鸭绿江断裂南西端黄海海域是未来发生中强地震的主要部位。本研究可为深入研究辽宁地区地震构造条件、编制第五代全国地震区划图提供基础资料。 相似文献
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发生于1969年的渤海Ms7.4地震是渤海海域惟一一个主震被现代仪器记录的大地震,对其发震断层的讨论争议颇多.2005～2008年,我们在主震震区进行了3个航次的高分辨率声学探测,获得了包括浅层单道地震、侧扫声纳以及CHIRP剖面等在内的数百公里综合地球物理观测资料.本文报道了对上述声学资料的研究结果.研究表明,在震区海底之下2～3 m发现了一条走向NE30°、长20 km、宽约3 km的微型凹陷带,地质时代为5000 a B.P.,沉积面的最大下凹幅度为1.5 m;在空间位置上微型凹陷带与BZ28断裂、余震活动分布基本一致,因此,微型凹陷带是BZ28断裂活动的结果,而A层底界的下凹变形则是1969年渤海7.4级地震活动的结果, BZ28断裂是该地震的发震断层.BZ28断裂呈NE30°走向,是郯庐断裂带的次级断裂,浅层地震剖面揭示其最新活动时间为全新世中晚期,根据地质时代以及断层的垂向位移量,计算得到BZ28断裂晚更新世以来的垂向活动速率约为0.05 mm/a,全新世为0.3 mm/a,具有活动强度增加的趋势. 相似文献
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发生于1969年的渤海Ms7.4地震是渤海海域惟一一个主震被现代仪器记录的大地震,对其发震断层的讨论争议颇多.2005~2008年,我们在主震震区进行了3个航次的高分辨率声学探测,获得了包括浅层单道地震、侧扫声纳以及CHIRP剖面等在内的数百公里综合地球物理观测资料.本文报道了对上述声学资料的研究结果.研究表明,在震区海底之下2~3 m发现了一条走向NE30°、长20 km、宽约3 km的微型凹陷带,地质时代为5000 a B.P.,沉积面的最大下凹幅度为1.5 m;在空间位置上微型凹陷带与BZ28断裂、余震活动分布基本一致,因此,微型凹陷带是BZ28断裂活动的结果,而A层底界的下凹变形则是1969年渤海7.4级地震活动的结果, BZ28断裂是该地震的发震断层.BZ28断裂呈NE30°走向,是郯庐断裂带的次级断裂,浅层地震剖面揭示其最新活动时间为全新世中晚期,根据地质时代以及断层的垂向位移量,计算得到BZ28断裂晚更新世以来的垂向活动速率约为0.05 mm/a,全新世为0.3 mm/a,具有活动强度增加的趋势. 相似文献
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兰州市地震活断层探测新进展 总被引：6，自引：0，他引：6
文中综述了兰州市地震活断层探测的最新进展情况。通过航、卫片解译,地质地貌调查,地球化学探测,浅层人工地震探测,电法探测,钻孔探测,特别是大型探槽等综合研究,对兰州市7条目标断层的新活动性提出了新的认识。修改了4条断层的最新活动时代,即金城关断层、雷坛河断层、寺儿沟断层和西津村断层等前人提出为QP3活动断层,探测结果为Q1p-Q2P断层;特别是否定了穿过市区的晚第四纪活动的刘家堡断层(Qh)和深沟桥断层(Q3P),明确了马衔山北缘断层西段为晚更新世—全新世活断层,并为1125年兰州7级地震的发震断层 相似文献
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We have studied the characteristics of the active faults and seismicity in the vicinity of Urumqi city, the capital of Xinjiang Autonomous Region, China, and have proposed a seismogenic model for the assessment of earthquake hazard in this area. Our work is based on an integrated analysis of data from investigations of active faults at the surface, deep seismic reflection soundings,seismic profiles from petroleum exploration, observations of temporal seismic stations, and the precise location of small earthquakes. We have made a comparative study of typical seismogenic structures in the frontal area of the North Tianshan Mountains, where Urumqi city is situated,and have revealed the primary features of the thrust-foldnappe structure there. We suggest that Urumqi city is comprised two zones of seismotectonics which are interpreted as thrust-nappe structures. The first is the thrust nappe of the North Tianshan Mountains in the west, consisting of the lower(root) thrust fault, middle detachment,and upper fold-uplift at the front. Faults active in the Pleistocene are present in the lower and upper parts of this structure, and the detachment in the middle spreads toward the north. In the future, M7 earthquakes may occur at the root thrust fault, while the seismic risk of frontal fold-uplift at the front will not exceed M6.5. The second structure is the western flank of the arc-like Bogda nappe in the east,which is also comprised a root thrust fault, middle detachment, and upper fold-uplift at the front, of which the nappe stretches toward the north; several active faults are also developed in it. The fault active in the Holocene is called the South Fukang fault. It is not in the urban area of Urumqi city. The other three faults are located in the urban area and were active in the late Pleistocene. In these cases,this section of the nappe structure near the city has an earthquake risk of M6.5–7. An earthquake M_S6.6, 60 km east to Urumqi city occurred along the structure in 1965. 相似文献
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Jia Rongguang Wang Zhicai Wang Jian Feng Zhize Liu Xi Zhai Zhenghong Zhu Jiany Jiang Zaofeng Wu Ziquan 《中国地震研究》2008,22(3):317-333
Buried faults in Weifang city and surrounding areas are studied with geophysical surveys such as shallow seismic survey and electrical exploration, and verified with engineering drilling. Six main faults are detected including the Yishul-Tangtou fault, Tangwu-Gegou fault, Hanting fault and Weixian fault, etc. The latest active age is determined by OSL, TL and ESR dating techniques. No active fault has been found so far in the Weifang urban area. Our results provide a scientific basis for land use and urban planning. 相似文献
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唐山地震发震构造的浅层地震探测 总被引：8，自引：2，他引：6
利用浅层地震探测方法,研究了唐山地震区１年前出现在卫星图像上的异常现象与发震构造的关系,探讨地震中长期预测的途径。结果表明：唐山地震断层是一条倾向ＮＷ的右旋走滑第四纪同生断裂,它错断了全新统,晚更新统,中更新统,和早更新统地层。 相似文献
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应用浅层地震勘探法对宁夏吴忠地区北部的浅部地壳结构和隐伏活动断裂进行研究。结果表明,该区存在2条隐伏断裂,分别为银川主断层南段和新华桥断层。推测银川主断层南段为近SN走向的W倾正断层,断层下盘地层界面一般呈近水平状展布,而在断层上盘,T_Q及其以下的地层界面向断面方向倾伏并显示出逆牵引现象,断层向上错断了第四系内部。钻孔联合地质剖面及浅层地震探测结果共同揭示新华桥断层为一条走向NE,倾向SW的正断层,深、浅地震测线控制的新华桥断层延伸长度9 km左右,向上错断了第四系内部的T_(02)界面。 相似文献
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通过在同一条测线上应用三种不同地震勘探手段(共偏移距地震反射法、横波反射法与高分辨率折射法)联合反演的方法,获得了测线控制地段内废黄河断层的确切位置、上断点埋深以及速度分布图像.探测结果表明:在薄覆盖层地区的断裂调查中,上述三种技术手段的联合反演要比单独使用其中任何一种手段更加可靠,并能从不同角度查明断层的位置、性质及其特征,为钻孔联合剖面位置的布设和钻孔深度的设计提供地震学依据.经高精度钻孔联合地质剖面证实,三种地震勘探方法反演得到的主要地层界面和构造特征都与钻孔联合地质剖面吻合较好.试验表明了上述三种地震勘探方法在基岩面埋深较浅地区联合反演的可行性以及地震勘探与钻孔联合地质剖面相结合的工作方法的有效性. 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 
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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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STUDY ON TANGSHAN-HEJIAN-CIXIAN EARTHQUAKE FAULT ZONE BY SHALLOW SEISMIC EXPLORATION METHOD 下载免费PDF全文
下载免费PDF全文 The location of the buried faults, the fault broken layers and the depth of breakpoints in the Tangshan-Hejian-Cixian seismotectonic zone are not clear. We implemented 4 shallow seismic exploration profiles on the Daming Fault, Cangxi Fault, and Dachengdong Fault. Line DZ1 is located on the Daming Fault in the southeast of Daming County. Five breakpoints were dectectd, which are all normal faults, with depths of 95~125m and displacements about 6~12m, offsetting late Pleistocene but not the Holocene. Line DZ2 is located in the east of Xianxian County to dectect the Cangxi Fault. Three breakpoints were detected, all are normal faults, with depths of 170~190m and displacements about 7~10m. The upper breakpoints of the three faults cut the middle Pleistocene. The lines DZ3 and DZ4 are located in the west of Litan Town, Dacheng County. Four breakpoints were detected, with the upper breakpoint depth of 120~130m and displacements about 5~15m. They are all normal faults, and the upper breakpoints of the faults cut the Pleistocene strata.
The result of the exploration of Cixian-Daming Fault is not consistent with the buried depth 1 200m proposed by XU Hua-ming. It is proved that the activity of the fault is also consistent with the overall activity of the Cixian-Daming Fault, which is an active fault since late Pleistocene.
The Dachengdong Fault and Cangxi Fault offset the middle Pleistocene strata. Although the late Pleistocene active faults are generally defined as active faults in the practice of active tectonics research in China, strong earthquakes in eastern China have shorter recurrence period, and earthquakes of magnitude 6 or so may also occur in some middle Pleistocene active faults.
During the compilation of GB18306-2015 “Seismic ground motion parameter zonation map of China”, there were no late Pleistocene active faults in the M6~6.5 potential source areas in eastern China. Therefore, we believe that the Dachengdong and Cangxi faults still have the ability to generate earthquake of magnitude 6 or so, and the faults have some similarities with the seismogenic structures of Xingtai earthquake swarm. Under the action of the latest tectonic stress field, the “deep faults” tearing ruptured successively and expanded upwards, resulting in stress migration and loading between two neighbouring en-echolon concealed faults, so, the Dachengdong and Cangxi faults are the product of this three-dimensional rupture process. The Dachengdong Fault is a “newly-generated” fault resulting from the tearing rupturing and upward expanding of the pre-existing concealed “deept faults” in the middle and lower curst. 相似文献
The result of the exploration of Cixian-Daming Fault is not consistent with the buried depth 1 200m proposed by XU Hua-ming. It is proved that the activity of the fault is also consistent with the overall activity of the Cixian-Daming Fault, which is an active fault since late Pleistocene.
The Dachengdong Fault and Cangxi Fault offset the middle Pleistocene strata. Although the late Pleistocene active faults are generally defined as active faults in the practice of active tectonics research in China, strong earthquakes in eastern China have shorter recurrence period, and earthquakes of magnitude 6 or so may also occur in some middle Pleistocene active faults.
During the compilation of GB18306-2015 “Seismic ground motion parameter zonation map of China”, there were no late Pleistocene active faults in the M6~6.5 potential source areas in eastern China. Therefore, we believe that the Dachengdong and Cangxi faults still have the ability to generate earthquake of magnitude 6 or so, and the faults have some similarities with the seismogenic structures of Xingtai earthquake swarm. Under the action of the latest tectonic stress field, the “deep faults” tearing ruptured successively and expanded upwards, resulting in stress migration and loading between two neighbouring en-echolon concealed faults, so, the Dachengdong and Cangxi faults are the product of this three-dimensional rupture process. The Dachengdong Fault is a “newly-generated” fault resulting from the tearing rupturing and upward expanding of the pre-existing concealed “deept faults” in the middle and lower curst. 相似文献
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新乡-商丘断裂是南华北盆地与渤海湾盆地、鲁西隆起的分界断裂,是一条长期活动的区域性深大断裂。浅层地震勘探与跨断层钻孔联合剖面探测工作已证实该断裂延津至封丘段的最新活动时代为晚更新世,本文通过对典型地震勘探剖面和钻探资料综合分析认为:新乡-商丘断裂延津至封丘段断裂结构复杂,新近纪以来构造样式在不同构造部位有显著差异。延津段在地震勘探剖面上浅部显示为负花状构造;封丘段变化较大,东部在剖面上为多组阶状正断层组合,形成了由断层带控制的构造背斜,平面上表现为NW向排列、走向NNE雁列状断层组合;西部结构单一,自东向西断裂控制的浅部地层变形范围增大,断层带逐步变宽。根据新乡-商丘断裂延津至封丘段剖面上的构造样式与平面上的组合模式,表明该段断裂最新活动具有走滑运动性质。 相似文献