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1.
The paper introduces the steps and methods of multi-approach,multi-level exploration of buried faults in thick Quaternary sediment regions by taking the test exploration of the Yinchuan active fault as example.Based on the comprehensive analyses of previous data,we choose the Xinqushao Village of Xingqing District of Yinchuan City as the test site for the comprehensive exploration.Firstly,we adopted shallow seismic investigation with group intervals of 10m,5m and 1m to gradually trace layer by layer the master fault of the Yinchuan buried fault from a deep depth to a shallow depth where drilling could be used.Then,with composite geological profile drilling,we determined the precise location and dip angle of the fault.The drilling show the buried depth of the upper offset point is 8.3m.Finally,large-scale trenching revealed that the actual buried depth of the upper offset point of the fault is 1.5m from the ground surface and there are paleoearthquake events of 5 stages.Combined with the preliminary result of corresponding sample age,we conclude the Yinchuan buried fault is a mid to late Holocene active fault.  相似文献   

2.
On the southeast coast of Fujian and its adjacent area, the NE-trending Changle-Zhao′an fault zone and several NW-trending faults that are genetically related to the former are well developed. With micro-relief analysis, the paper deals with the Quaternary activity of the faults and the tectonic stress field since the late Pleistocene in this region. The results indicate that the micro-relief of the NE-trending Changle-Zhao′an fault zone and the genetically related NW-trending faults is characterized by vertical and horizontal movements since the Quaternary; the faults in the region have undergone two active stages since the Quaternary, i.e. early Quaternary and late Pleistocene; since the late Pleistocene, the movement of the NE-trending faults showed a right-lateral strike-slip, while that of NW-trending faults a left-lateral strike-slip, indicating a NWW-SEE oriented horizontal principal stress of the regional tectonic stress field  相似文献   

3.
A detailed investigation permitted us to obtain quantitative data concerning fine geometric structures of 4 faults of the active Maxianshan-Xinglongshan fault system and the latest movement along them. Of them the northern Maxianshan border fault is a large-scale, strongly active Holocene reverse sinistral strike-slip fault, the other 3 faults, the southern Maxianshan border fault and the southern Xinglongshan border and the northern Xinglongshan border faults are the accompanying active late-Pleistocene thrust faults, which are incorporated into the main strike-slip fault, the northern Maxianshan border fault at depth. It is the most important earthquake-controlling fault in the Lanzhou area, the fault influences and constrains the seismic activity in the area.  相似文献   

4.
基于钻探的芦花台隐伏断层晚第四纪活动特征   总被引:1,自引:0,他引:1  
The Luhuatai fault is one of the important buried tectonics in the Yinchuan basin. Based on the results of shallow seismic exploration, we conducted composite drilling section exploration and dating of the samples from boreholes. Some useful data was obtained, such as the depth of the upper breaking point, the latest activity age, displacement in the late Quaternary, and slip rates, etc. This study shows that the activity is different between the north and south segment along the Luhuatai fault. The north segment is a Holocene fault, while the south segment is a late mid-Pleistocene fault. From north to south along the north segment of Luhuatai fault, the activity has been enhanced, and the faulting is stronger in late Pleistocene than Holocene.  相似文献   

5.
The location and late Quaternary activity of the Central-North Segment of the Taihang Mountains Piedmont fault zone have been studied by shallow seismic survey and combined drill exploration.Our results show that the Baoding-Shijiazhuang fault and the Xushui fault were active in the late Pleistocene,but the south Xushui fault has been inactive since the late Pleistocene.The maximum magnitude of potential earthquake of the faults is 6.0.  相似文献   

6.
Taking the Huaihe to the Nvshanhu segment of the Tanlu (Tancheng-Lujiang) fault zone as the main research target to explore whether there has been new activity since the late Quaternary, and based on the interpretation of remote sensing images and repeated surface investigations, we excavated trenches at the sections where the tectonic landform is significant, identified and recorded the deformation patterns of the fault and analyzed the activity behavior. Samples of new activity and deformation were collected and oriented slices were ground based on the samples'' original state to make the micro structural analysis and demonstration. All of the above research shows very clear linear tectonic geomorphology along the fault, three trenches across the fault zone all revealed new deformation traces since late Quaternary. The latest stratum dislocated by the fault is the late Quaternary and Holocene. The main slip mode is stick slip, as represented typically by fault scarps, wedge accumulation, the faults and the filled cracks and so on. In general, it shows the characteristics of brittle high-speed deformation and belongs to the prehistoric earthquake ruins. The above understanding was confirmed partially by microscopic analysis. In addition, the similarities and differences and the possible reasons for the characteristics of the latest activities of the Tancheng-Lujiang fault zone in the north and south of the Huaihe River regions are also discussed in this paper.  相似文献   

7.
Marine Active Fault Exploration and Paleoearthquake Research   总被引:5,自引:0,他引:5  
Marine active fault exploration and Paleoearthquake research are still a gap in China.The paper gives a review on major research methods and new progress made abroad,including submarine survey boat.seismic reflection and acoustic reflection.Through detailed studies of offset history of 10 ka to 30ka,it is possible to determine paleoearthquake recurrent intervals and elapsed time since last major earthquake.It is suggested that active fault exploration can be carried out by acoustic exploring method in large earthquake region of Bohai Sea.Paleoearthquake activity history can be revealed and earthquake risk in the future can be predicted.  相似文献   

8.
The opinions of two papers carried in the journal "Seismology and Geology" are discussed in the paper.One is that the Tangshan fault is a high-angle,west-dipping and thrust with strike-slip fault.The other is that the Fuzhuang-Xihe fault distributed on the east side of Tangshan city is the seismogenic fault that caused the Tangshan earthquake.For the former opinion,it needs to explain the relationship between the active style of the thrust Tangshan fault and the formation genesis of a Quaternary depression along the west side of Tangshan city.For the latter opinion,if the Fuzhuang-Xihe fault is the seismogenic fault of the Tangshan earthquake,it needs to explain the genesis relationship between this west-dip slip fault zone and the strike-slip surface fissure zone that extends through Tangshan city.And it needs more evidence exclude the possibility that the surface rupture belongs to the rupturing of a secondary structure.This paper suggests doing more work on the active fault that controls the Caobo Quaternary depression.  相似文献   

9.
Analysis of fault outcrops and trench sections indicates fault displacements of 0.2m - 6.0 m on the bottom paleosol layer of the Epipleistocene with the maximum rate of 0.047 mm/a and an average displacement of 1.1 meters. The activity appears as fissures on the fault surface in the late Epipleistocene and there is no obvious displacement. The fault activity is weak and the most active segment is the Bailuyuan segment.  相似文献   

10.
By computing and classifying the data of gully offset obtained from field surveys along the Tianjingshan fault zone and estimating the ages of three types of gullies,the strike-slip rates along the fault zone are discussed in different time intervals and fault segments.The results suggest that the intensity of activity along the fault zone is not strong,but the differences between different time intervals and fault segments since the late Pleistocene have been obvious.The average rates range from 0.23 mm/a to 1.62 mm/a.The largest average rate is 1.40 mm/a,which occurred in the early and middle of late Pleistocene along the western segment of the fault zone.Since the late stage of the late Pleistocene,the center of faulting activity of the fault zone has shifted to the middle segment,and the average slip rates range have changed from 1.30 mm/a to 1.63 mm/a.  相似文献   

11.
在化探定位的基础上,通过浅层地震勘探、钻探地质剖面和新地层年代学等多手段探测研究,首次查明了聊考隐伏断裂晚第四纪以来的位错量和最新一期活动时代,厘定了断裂位错上断点达地表20m以下,最新一期活动在全新世早期,属浅埋的隐伏活动断裂。断裂第四纪以来的平均位错速率为0.12mm/a,在中国东部属中等倔强的一类隐伏活动断裂。  相似文献   

12.
聊城-兰考隐伏断裂第四纪活动性的综合探测研究   总被引:13,自引:3,他引:10       下载免费PDF全文
在综合分析区内重、磁、石油物探等资料的基础上 ,采用化探 (气氡、气汞法 )定位 ,浅层地震勘探、钻探地质剖面和新地层测年等综合研究 ,确定了聊城 -兰考 (简称聊考 )隐伏断裂的准确位置、第四纪各时段位错量和最新一期的断错时代。结果表明 ,断裂向上破裂位错影响到地表以下2 0m左右 ,属全新世早期活动断裂 ,其平均位错速率为 0 12mm/a  相似文献   

13.
正谊关断裂横贯贺兰山北部山区,为一长期活动的区域性大断裂带。本文根据大比例尺航卫片解译,野外实际调查资料和~(14)C年代数据,讨论了该断裂带的平面展布、第四纪以来断裂的运动方式,活动强度、最新活动时代及古地震等问题。该断裂带的正谊关断层段新活动强烈,第四纪以来呈明显的左旋走滑活动。断错地貌显示,其最大一组水平错距为1800—2000米,最小一组错距为10—20米。在毛呼都格音沟及葡萄泉子沟发现两处古地震遗迹,估计该两次古地震事件发生在距今约6000年左右。  相似文献   

14.
通过对汗母坝-澜沧断裂晚第四纪地质、地貌实地调查与测量,并结合前人研究成果,讨论了该断裂晚第四纪最新构造活动特征。综合分析认为,汗母坝-澜沧断裂为一条以右旋走滑为主的全新世活动断裂,长约120 km,整体走向NNW。该断裂活动习性具有明显的分段特征,北段称为汗母坝断裂,是1988年耿马7.2级地震的发震断裂;南段称为澜沧断裂,是1988年澜沧7.6级地震的发震断裂之一。晚第四纪以来其新活动形成了丰富的断错地貌现象,如冲沟和山脊右旋位错、断层沟槽、断层垭口、断层陡坎、断陷凹坑等。根据断裂断错地貌特征的相应资料估计,该断裂晚第四纪右旋走滑速率约为(4.7±0.5) mm/a。  相似文献   

15.
银川盆地西大滩隐伏断层晚第四纪活动特征   总被引:2,自引:1,他引:1       下载免费PDF全文
西大滩隐伏断层位于银川盆地北部,是石嘴山市活断层探测项目的目标断层之一。在浅层地震勘探的基础上,通过钻孔联合剖面探测和钻孔样品年龄测试,获得断层上断点埋深、主要标志层断距及沉积年龄等数据,估算了晚第四纪不同时段断层的滑动速率,结合地层变形情况探讨了该断层晚第四纪的活动特征。结果表明,西大滩隐伏断层自12 275±45aB.P.以来没有发生明显活动,属晚更新世末活动断层;晚更新世以来断层活动偏弱,平均滑动速率为0.024mm/a;除断层活动外,伴随着地层倾斜变形;两者均具间歇活动的特点,最小间隔约6 600a,最大间隔期12 275a。  相似文献   

16.
将军山—白水断裂是渭河盆地北缘断裂东段的一分支,位于将军山、东太白山山前,向北东延伸至白水县境内,已有资料及研究成果认为其为晚更新世活动断裂。通过地貌地质调查、音频大地电磁法勘探、浅层地震勘探、钻孔联合剖面探测、第四纪沉积物年代测试等方法,对将军山—白水断裂的展布与活动性进行研究。结果表明该断裂总体走向为NE向,倾向S,为一山前隐伏断裂,最新活动时代为中更新世晚期,未发现晚更新世以来活动的证据,判断其为中更新世活动断层。  相似文献   

17.
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   

18.
商丹断裂南阳盆地第四纪活动研究   总被引:1,自引:0,他引:1  
为了研究商丹断裂的空间展布及断裂活动性特征,跨断裂布设了4条浅层地震勘探测线和1条钻孔联合地质剖面.综合分析表明,商丹断裂为一条走向NWW的正断层,钻孔联合地质剖面揭示断裂上断点埋深为13—19 m,最新活动时代为中更新世晚期.  相似文献   

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