共查询到20条相似文献，搜索用时 156 毫秒
1.
通过对福建东南沿海海拔50m以下几个地貌面的时代确定,研究了长乐-诏安NE向断裂带和与之相交切的NW向断裂带第四纪以来的活动性。结果表明:区内50m以下几个地貌面分为侵蚀-剥蚀阶地和堆积阶地,属晚更新世以来几个时期所形成;断裂在切割某个地貌面时,其地貌面的形成年代可确定为该断裂的活动年代;长乐-诏安NE向断裂带中的平潭青峰-东山澳角断裂的有些地段为晚更新世晚期(Q3p)活动断裂,垂直滑动速率为1.1～2.2mm/a;长乐-东山前梧断裂主要活动时代在中更新世(Q2p);九龙江下游NW向断裂带中的江东桥(北溪)-海沧断裂,其NW段江东桥(北溪)断裂为早第四纪(Q1p-2)断裂,SE段海沧-钱屿断裂为晚更新世(Qp3)活动断裂 相似文献
2.
罗云山山前断裂中段土门-贾朱村晚第四纪断错地貌特征 总被引：2，自引：0，他引：2
罗云山山前断裂位于山西临汾盆地西侧,控制着盆地的西界。通过对该断裂1∶ 5万地质填图、对河流冲沟阶地及山前断错地貌的调查,介绍了罗云山山前断裂中段土门-贾朱村晚第四纪断错地貌特征。罗云山山前发育D1、D2、D3 等3 级洪积扇,罗云山山前断裂上升盘冲沟发育T1 ～ T5 等5 级阶地。D1 洪积扇与T1、T2 阶地形成于全新世早中期;D2 洪积扇与T3 阶地形成于晚更新世中晚期;D3 洪积扇与T4、T5 阶地形成于中更新世中晚期。罗云山山前断裂中段不同部位断错地貌特征差异较大,D1 洪积扇的断错在席坊沟一带断距约2. 9m;在金殿镇峪口村南西山前断错约3m。D2 洪积扇的断错在土门镇南西堡子村约2. 5m;在杨家庄村西山前断错约4m;在景村西山前断错约6m;在襄陵镇浪泉沟南西侧山前断错约7. 7m。罗云山山前断裂中段山前断错地貌明显,其最新活动时代为全新世。其中,土门段最新活动时代为全新世早期,龙祠段最新活动时代为全新世中晚期。罗云山山前断裂中段晚更新世中晚期以来活动速率为0. 18～ 0. 54mm / a,由北向南活动呈增强趋势;全新世早中期以来活动速率为0. 4 ～ 0. 9mm / a,断裂活动主要集中于席坊沟-峪口一带。罗云山山前断裂中段从晚更新世中晚期到全新世活动速率有增大的趋势,这与该断裂上升盘冲沟阶地从晚更新世中晚期到全新世抬升速率有增大的趋势以及临汾盆地从晚更新世晚期到全新世沉降速率也有增大的趋势具有较好的一致性。 相似文献
3.
近年来，在青岛地区对第四纪断裂的空间展布、结构面和地貌特征及其与第四纪地层的关系等进行了较为详细的研究，并采用热释光（TL）及电子自旋共振（ESR）法对断层物质及断裂带上覆的第四纪堆积物的年龄进行了测定。文中对上述研究成果进行了初步总结，认为青岛及邻区内的NE向断裂在空间展布、地貌特征及最新活动时代等方面具有相似性，它们的最新活动时代为中更新世中晚期，晚更新世以来不活动。除此以外未见其它方向的晚更新世以来活动的断裂，结合历史地震及现代小震活动特点分析，认为该区域内无≥6级地震的发生条件，但有发生5级左右地震的可能性。 相似文献
4.
沈阳长白乡-观音阁断裂、抚顺浑河断裂的定位和活动性研究 总被引：3，自引：0，他引：3
本文基于对沈阳长白乡-观音阁断裂,以及抚顺浑河断裂开展的1:10000地质地貌填图工作,获得了这两条断裂在最老第四纪地层热释光的测年结果,它们分别为(112±6.7)ka和(150±9.0)ka。长白乡-观音阁断裂为一沿丘陵山地前缘分布的断裂,由2—3条分支断裂组成,最新的断面活动显示为压扭性正断层性质。断裂在晚更新世坡洪积扇堆积形成以来没有活动显示。3条浅层人工地震测线探测结果表明,其上断点均未错断第四系上更新统底界。断裂为中更新世活动断裂,晚更新世以来没有活动。浑河断裂为一沿丘陵山地前缘分布的断裂,由3—4条分支断裂组成,最新的断面活动显示为压扭性正断层性质。断裂在晚更新世坡洪积扇堆积形成以来没有活动显示。5条浅层人工地震测线探测结果表明,其上断点均在第四系上更新统底界以下。断裂为中更新世活动断裂,晚更新世以来没有活动。 相似文献
5.
文中通过福建龙海—漳浦沿海主要断裂的玄武岩喷发,断裂两侧第四纪以来形成的地貌面和海相地层的差异性变化等特点,分析了断裂晚第四纪以来的活动特征及断裂构造的组合特征。研究结果表明:龙海流会-漳浦将军澳断裂在新近纪—第四纪晚更新世早期 (N2—Q3p)有玄武岩多次循其喷发,晚更新世(Q3p)活动明显,属晚更新世活动断裂;龙海港尾 -漳浦湖西断裂亦属晚更新世(Q3p)活动断裂,断裂下盘上升速率为 1. 11mm/a。这 2条断裂将本区切割形成港尾地堑、南太武山地垒、流会-将军澳以东海域地堑 相似文献
6.
遥感影像解译和野外地质地貌调查表明,龙陵-瑞丽断裂(南支)北段是以左旋走滑为主兼张性正断的区域性活动断裂。根据一些断错地貌点的大比例尺填图、实地测量及其年代学分析,确定了该断裂为全新世活动断裂,断裂晚更新世以来的平均水平滑动速率为2.2mm/a,平均垂直滑动速率为0.6mm/a;全新世以来的平均水平滑动速率为1.8～3.0mm/a,平均垂直滑动速率为0.5mm/a。断裂晚更新世以来的滑动速率在不同的时间尺度上变化不大,反映了该断裂晚更新世以来的活动强度比较平稳 相似文献
7.
近年来 ,在青岛地区对第四纪断裂的空间展布、结构面和地貌特征及其与第四纪地层的关系等进行了较为详细的研究 ,并采用热释光 (TL)及电子自旋共振 (ESR)法对断层物质及断裂带上覆的第四纪堆积物的年龄进行了测定。文中对上述研究成果进行了初步总结 ,认为青岛及邻区内的NE向断裂在空间展布、地貌特征及最新活动时代等方面具有相似性 ,它们的最新活动时代为中更新世中晚期 ,晚更新世以来不活动。除此之外未见其它方向的晚更新世以来活动的断裂 ,结合历史地震及现代小震活动特点分析 ,认为该区域内无≥ 6级地震的发生条件 ,但有发生 5级左右地震的可能性 相似文献
8.
塔尔湾断裂活动时代厘定及地貌陡坎成因分析 总被引：4，自引：2，他引：2
阿尔金断裂东段北侧发育了多条NW向断裂,塔尔湾断裂是其中规模最大的塔尔湾-登登山-池家刺窝断裂的西段。该断裂总体走向NW,长约10km,在卫星影像上为一笔直的线性陡坎,地貌上为高几十cm至5m的地形陡坎。陡坎倾向NE,组成陡坎的地层主要有早更新世砾岩和全新世风积砂土等。通过地形剖面测量得到,由全新世风积砂组成的地貌陡坎高5m左右,由早更新世砾岩组成的地貌陡坎高1m左右。垂直地貌陡坎开挖的探槽揭示出,塔尔湾断裂为SW倾的逆断层,表现为新近纪泥岩逆冲于早更新世砾岩之上,断距为0.5m左右。全新世风积砂及晚更新世戈壁砾石层覆盖于断层之上,没有被错断。断裂上盘为新近纪泥岩,富含地下水,因此植被较发育;由于植被的保护及固砂作用,风积砂不断堆积并保存下来,风积沙层逐渐增高。下盘除地表有几十cm厚的戈壁砾石层外,下部均为胶结坚硬的早更新世砾岩,不含地下水,植被不发育。全新世风积砂土只发育在塔尔湾断裂上盘,下盘没有全新世地层发育;早更新世砾岩上的地貌陡坎高度远远小于全新世风积砂土上地貌陡坎的高度。这些都表明由全新世风积砂组成的地貌陡坎不是断裂活动形成的,而是外动力作用造成的。因此,塔尔湾断裂是一条早中更新世逆断裂。 相似文献
9.
10.
11.
Through simultaneous inversion of earthquake hypocenters and velocity structure, we obtained the precise locations of earthquakes occurring from 1981 to 2013 in northern Shanxi and the 3D velocity structure, and analyzed emphatically the Kouquan Fault. The result of earthquake relocation shows that earthquakes are concentrated in the central-north segment of Kouquan Fault and the distribution is sparse towards both south and north end of the fault, which indicates that the strong activity is in the central-north segment of Kouquan Fault and the seismicity becomes weaker towards both ends. The result of velocity structure shows that the earthquake concentrated segment of Kouquan Fault is on the side of relative low-velocity area in the high-velocity body, and the south segment of Kouquan Fault is the continuous low velocity. We can recognize the velocity gradient zone from the obvious depression near the Kouquan Fault, which, as we preliminarily speculate, may be the evidence of the presence of Kouquan Fault(or basement detachment)at the deep part. The parallel velocity profile (velocity ratio profile) to Kouquan Fault shows that the earthquake cluster in the central-north segment of Kouquan Fault is located in the abrupt change zone from high to low velocity(from high to low velocity ratio). 相似文献
12.
CORRELATION BETWEEN GAS GEOCHEMICAL EMISSION AND FAULT ACTIVITY OF THE YUXIAN-GUANGLING AND KOUQUAN FAULTS 
下载免费PDF全文
下载免费PDF全文 Soil gas emission is closely related to tectonic and seismic activity and has been widely used to track active faults and monitor seismicity in the upper crust. Because active fault plays an important role as the channel of the earth's deep gas upward migration due to its high permeability and porosity, the geochemical characteristics of soil gas in fault zone is a good indicator of tectonic fracture and activity. In order to study the soil gas geochemical emission intensities and its correlation to fault activity, fluxes of Rn, Hg and CO2 in soil gas and the ground resistivity were surveyed across the Yuxian-Guangling Fault and Kouquan Fault which are both Quaternary active faults in the border area of Shanxi Province, Hebei Province and Inner Mongolia Autonomous Region. In 2017, soil gas fluxes were measured in 2 profiles consisting of 10 and 9 wells of depth of 3.0m across the fault scarps in Yuxian-Guangling Fault and Kouquan Fault, respectively. Resistivity tomography sections were attained by ground resistivity survey with electrode spacing of 5.0m along the profiles of soil gas measurement. The gas geochemical data show that there exist two abnormal flux peaks across the Yuxian-Guangling Fault and one in the Kouquan Fault. The high density resistivity measurement shows that fault breccia and fractured rocks zones are developed under the measured faults, where higher values of soil gas flux are also observed. Fractures with high gas permeability in the strata favor the transfer and migration upward of soil gases, which results in the anomalies of gas flux value. In addition, the anomalies of gas flux values are spatially identical with the occurrence of the fault scarps. The soil gas degassing rate of Yuxian-Guangling Fault is higher than that of Kouquan Fault. The research results of high density electrical prospecting and previous tectonic activity show that low-resistance bodies are more developed and the fault activity is stronger with higher slip rate, which leads to the more intense emission of soil gas in Yuxian-Guangling Fault. The conclusions can be made that soil gas geochemical characteristics and degassing rate in fault zone is closely correlated to the tectonic activity and fracture degree. Combination of geochemical and geophysical methods is an efficient way for the monitoring and study of fault activity to estimate the possible earthquake hazards. 相似文献
13.
野外调查表明 ,口泉断裂断错了断面附近的 3级地貌面 ,包括大同盆地西侧全新世形成的洪积扇后缘及位于洪积扇冲沟内的Ⅰ ,Ⅱ级阶地。其中冲沟内Ⅱ级阶地为剥蚀阶地 ,Ⅰ级阶地为堆积阶地 ,Ⅰ级阶地面的地层时代距今 2 52ka。在该断裂的悟道及上黄庄 2个地点开挖的大探槽表明 ,在距今 1 2 3万年以来该断裂曾发生 4次古地震事件 ,其中 3次分别发生在接近距今 2 52 ,5 6 8,13 73ka。另一次古地震事件发生在距今 6 76～ 10 82ka。这些数据有可能反映了口泉断裂具备准周期的强震活动。这 4次古地震事件的平均间隔约为 3 74ka ,最新一次古地震与上一次事件的时间间隔约为 3 16ka。 2个大探槽各次事件的平均最小同震垂直位移为 1 8m。这些资料对重新评价口泉断裂未来的地震潜势具有重要意义 相似文献
14.
沂沭断裂带重力场及地壳结构特征 总被引：5，自引：2，他引：3
沂沭断裂带为郯庐断裂带山东段,新构造运动显著,是华北地区的强震活动带之一。文中收集了该地区的布格重力数据,利用小波多尺度分析方法对重力场进行有效分离,研究区域地壳结构特征及断裂空间展布,并应用Parker变密度模型对区域莫霍面进行反演分析,得到以下几点结论:1)重力区域场显示,沂沭断裂带形成了NNE走向的大型重力梯度带,分隔了鲁西、鲁东地块,成为区域内重要的地球物理分界线。2)重力局部场显示,中上地壳结构复杂,沂沭带内部呈现两堑一垒的重力异常格局,5条主干断裂形成线性梯度带分布于东、西地堑内,鲁西块体的多条NW向活动断裂交切于沂沭断裂带,多数断裂只交切于西地堑,而蒙山山前断裂和苍尼断裂横穿沂沭断裂带;下地壳结构相对简单,发生明显的褶曲构造,表现出大规模高、低密度异常相间排列的典型特征。3)区域莫霍面形态东高西低,沂沭断裂带形成了莫霍面陡变带,造成了东西分异格局,潍坊东—莒县—临沂一线出现莫霍面上隆区,具有强震发生的深部孕震环境。4)区域内地震多发于高、低重力异常转化带之间,特别是活动断裂对应的重力梯度条带之上,地震的发生与断裂活动有着密切的关系,沂沭断裂带地震活动性最强,且东地堑强于西地堑。 相似文献
15.
文中以东昆仑断裂带周围分布的27个GPS站点的地壳运动速率矢量为约束,利用半无限弹性空间三维断裂位错模型,反演了东昆仑断裂、柴达木盆地北缘断裂、玛尼-玉树断裂和玛尔盖茶卡断裂带在2001年昆仑山口西MS8.1地震之前的运动速率,并认为这些断裂带以反演出的运动速率错动所形成的形变场可以作为震前的背景地壳形变场。基于这一具有构造意义的背景速度场资料,计算了区域地壳应变率场和地震矩累积率场。结果表明,昆仑山口西地震前,东昆仑断裂的东西大滩段和玛尼-玉树断裂西段为该区域2个最显著的地震矩累积率高值区,其中东昆仑断裂的东西大滩段高值区为后来的昆仑山口西MS8.1地震的发震段 相似文献
16.
天津断裂分为天津南断裂和天津北断裂。根据人工地震探测结果,分别在天津静海县城西、西青区炒米店村、小南河村以及宁河县朱头淀村布设了4条钻孔剖面,对这2条断裂开展了钻孔勘探工作。经微体古生物鉴定,获得了各钻孔的海相层位置;经地层年代测试,确定了第1、第2和第3海相层的年代;通过以海相层为标志层的地层对比,并结合小南河村BZ1、TN3孔古地磁的测试结果,对这2条断裂的活动性进行了分析研究。结果表明,天津南断裂晚更新世以来未发现有过活动的迹象,其最新活动年代可能在中更新世。而天津北断裂也未发现晚更新世以来存在活动的迹象,该断裂在早更新世早期可能有过活动。由此可见,天津南断裂活动性可能要强于天津北断裂。同时发现,第2、第3、第4海相层在不同的地区存在不同程度的缺失现象。因此,在将其用于地层对比时,必须同时确定各海相层的地质年代,否则对比结果可能会出错。对于发生年代存在争议的第2海相层,认为其形成时间应在7万a左右。 相似文献
17.
文中利用遥感影像分析了徐州废黄河断裂带的空间展布及与邵楼断裂的交切关系,利用重磁资料研究了废黄河断裂带的深部几何结构及与郯庐断裂带西边界的交切关系。二阶布格重力异常小波变换细节图反映出徐州废黄河断裂带的深度为7～8km,而三阶和四阶重力异常细节图反映的深度分别为9～11km和15～18km。研究结果表明,废黄河断裂带向SE延伸至九顶附近,向下的切割深度约为 8～9km。NW向的废黄河断裂带截切邵楼断裂致使邵楼断裂构造线自东北向西南由N60°E转至N45°E。废黄河断裂带与郯庐断裂带不相交。废黄河断裂带属于前第四纪断裂,活动性较弱。 相似文献
18.
LIMITATION OF CURRENT TECTONIC DEFORMATION MODES IN THE WESTERN MARGIN OF ORDOS BASED ON SEISMIC ACTIVITY CHARACTERISTICS 下载免费PDF全文
下载免费PDF全文 ZHAN Hui-li ZHANG Dong-li HE Xiao-hui SHEN Xu-zhang ZHENG Wen-jun LI Zhi-gang 《地震地质》1979,42(2):346-365
Due to the interaction between the Tibetan plateau, the Alxa block and the Ordos block, the western margin of Ordos(33.5°~39°N, 104°~108°E)has complex tectonic features and deformation patterns with strong tectonic activities and active faults. Active faults with different strikes and characteristics have been developed, including the Haiyuan Fault, the Xiangshan-Tianjingshan Fault, the Liupanshan Fault, the Yunwushan Fault, the Yantongshan Fault, the eastern Luoshan Fault, the Sanguankou-Niushoushan Fault, the Yellow River Fault, the west Qinling Fault, and the Xiaoguanshan Fault.
In this study, 7 845 earthquakes(M≥1.0)from January 1st, 1990 to June 30th, 2018 were relocated using the double-difference location algorithm, and finally, we got valid locations for 4 417 earthquakes. Meanwhile, we determined focal mechanism solutions for 54 earthquakes(M≥3.5)from February 28th, 2009 to September 2nd, 2017 by the Cut and Paste(CAP)method and collected 15 focal mechanism solutions from previous studies. The spatial distribution law of the earthquake, the main active fault geometry and the regional tectonic stress field characteristics are studied comprehensively.
We found that the earthquakes are more spatially concentrated after the relocation, and the epicenters of larger earthquakes(M≥3.5) are located at the edge of main active faults. The average hypocenter depth is about 8km and the seismogenic layer ranges from 0 to 20km. The spatial distributions and geometry structures of the faults and the regional deformation feature are clearly mapped with the relocated earthquakes and vertical profiles. The complex focal mechanism solutions indicate that the arc-shaped tectonic belt consisting of Haiyuan Fault, Xiangshan-Tianjingshan Fault and Yantongshan Fault is dominated by compression and torsion; the Yellow River Fault is mainly by stretching; the west Qinling Fault is characterized by shear and compression. The structural properties of the fault structure are dominated by strike-slip and thrust, with a larger strike-slip component. The near-north-south Yellow River Fault is characterized by high angle NW dipping and normal fault motion.
Based on small earthquake relocation and focal mechanism solution results, and in combination with published active structures and geophysical data in the study area, it is confirmed that the western margin of Ordos is affected by the three blocks of the Tibetan plateau, the Alax and the Ordos, presenting different tectonic deformation modes, and there are also obvious differences in motion among the secondary blocks between the active faults. The area south of the Xiangshan-Tianjingshan Fault has moved southeastward since the early Quaternary; the Yinchuan Basin and the block in the eastern margin of the Yellow River Fault move toward the SE direction. 相似文献
19.
利用多时相、多波段卫星图像,研究1979年五原6.0级地震、1989年大同-阳高6.1级地震和1996年包头西6.4级地震震区的构造活动信息,结合前人的烈度调查资料,探讨这些强震发生的地质构造环境。研究表明:1979年五原6.0级地震发生在NE向海子堰断裂与NW向五原西断裂交会的部位。五原6.0级地震高烈度区等震线长轴呈NE向,与海子堰断裂一致,是五原地震的发震构造。1996年包头西6.4级地震发生在由陡崖和沟槽地貌显示的NEE向乌拉山北缘断裂与NW向新生砂石厂断裂交会的部位。包头西6.4级地震高烈度区等震线长轴呈NE向,与乌拉山北缘断裂接近,该断裂是包头西6.4级地震的发震构造。2次地震高烈度区长轴与低烈度区长轴走向相差近90°,这是因为除发震构造外,烈度区还受一组与之交会的共轭断裂活动的影响。1989年大同-阳高6.1级地震,发生在从六棱山腹地向大同-阳高盆地延伸的NNE向大王村-西要泉断裂上,该断裂是大同-阳高地震的发震构造 相似文献
20.
THE CENOZOIC TECTONICS AND SEISMIC ACTIVITY OF XINZHENG-TAIKANG FAULT IN THE SOUTHERN EDGE OF TAIKANG AREA 下载免费PDF全文
下载免费PDF全文 On the basis of dividing and comparison of the Neogene strata and their bottoms revealed by 7 drill holes in Taikang area, we completed 101 seismic profiles with a total length of 4991km. Seismic data were compared and interpreted. The results indicate that Xinzheng-Taikang Fault, as a blind fault extending from Xinzheng to Taikang, which was considered as an EW striking fault from Xuchang to Taikang before, is the boundary of Taikang uplift and Zhoukou depression, controlling the sedimentation since Neogene Period. So we named the fault the Xinzheng-Taikang Fault, which is composed of two branches, mainly, the east and west branches. The west branch strikes northwest, dipping northeast with steep angles, and the fault plane extending more than 140km in length. As revealed on the seismic profiles, the eastern segment of the west branch is normal fault, while the west segment of the branch shows characteristics of strike-slip fault. The east branch trends NW-NEE, dipping SW-SSE with the length of about 50km. Two branches form a minus flower structure, indicating the strike slip-extension tectonic background. The bottom of Neogene strata is offset about 120m by the east branch, 20m by the west branch, and the bottom of Quaternary is probably offset too. Meanwhile, latest studies suggest that the composite strip of the two branches of Xinzheng-Taikang Fault, which is a tectonic transfer zone, is the subduction zone between the two strike-slip faults. The tectonic stress tends to be released by the east-west branch fault, and the zone should be the seismogenic structure for the recent seismicity in Taikang area. In 2010, the latest earthquake ofMS4.7 occurred in this area, causing 12 people wounded. The seismogenic structure was considered to be the Xinzheng-Taikang Fault. So locating the fault exactly is of great importance to disaster prevention. 相似文献