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断层运动方式与滑动速率是断层活动性研究和地震危险性判定的重要参数。本文基于山西断陷带多年积累的跨断层水准观测资料,在处理与重构的基础上采用断层活动性分析方法,基于构造分区给出各构造区主要断层现今运动特征。结果表明,山西断陷带主要断层在观测期内以继承性正断运动为主,各盆地断层运动特征具有显著差异,表现为南、北两段的垂直活动量明显大于中段,其中,忻定盆地累积变化量值最小。从断层垂直活动速率来看,五台山断裂、系舟山山前断裂、唐河断裂和霍山山前断裂跨断层测段活动速率明显低于全区水平; 受长期构造应力加载及区域中强地震影响,各时段断层运动也存在差异变化,下达枝、亭旨头、太原、广胜寺等部分跨断层测段表现出明显的断层逆继承运动、断层相对闭锁等特征。 相似文献
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张家口断裂第四纪构造变形与活动性研究 总被引：8，自引：4，他引：4
本文根据野外详实资料对张家口断裂的构造变形和活动性进行分析与研究,结果表明:断裂由西、中、东3段组成,各段多由北西向和近东西向2组多条次级断层组成,总体呈北西西走向展布,长达70km,控制着张家口及附近的第四纪构造演化和地貌发育;北西向断层构成断裂的主体,为高角度的逆(或正)走滑断层,近东西向断层较短,表现为正倾滑,第四纪期间2组断层持续活动,以脆性变形为特征;断裂端部段落与北东向断裂交汇,活动性较弱,构造表现不甚清楚,中部段落活动强烈,晚更新世以来单条断层的平均垂直活动速率大于0.07—0.30mm/a,总的垂直活动速率可能达到1.33mm/a。 相似文献
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以天津市活断裂探测资料为基础,通过对天津断裂的地质构造、第四纪活动性,深部构造、构造应力场与形变场及地震活动性等的研究,综合判定了天津北、天津南断裂的活动性与构造特征;利用地震地质、历史与现今地震活动性资料,建立了按500a归算的震级-频度关系模型,拟合了天津地区的最大震级上限Mmu与at/b的关系,用于对区内各断层小区中-弱隐伏活动断层潜在地震最大震级的评估。采用泊松概率模型,估算出天津南断裂未来50～200a发生地震的最大震级、发生概率及复发周期等定量参数 相似文献
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赣江断裂带是江西省境内一条重要的区域性大断裂。断裂涉及九江、南昌和吉安等江西重要经济区,因此充分研究该断裂活动性对认识断裂沿线分布的历史地震的发震构造及规划断裂沿线城市的经济建设有科学意义。大致以丰城为界,赣江断裂北段(丰城—湖口段)和南段(吉水—丰城段)走向有明显的变化,北段走向NNE,南段走向NE,断层南北两段地震活动性略有不同,北段沿线记录地震多于南段。针对断层隐伏区采用了浅层地震勘探法和跨断层综合地质剖面法相结合的研究方法、对断层出露区采用断层剖面出露点观察调查法。综合研究结果表明:赣江断裂南、北两段的最新活动性时代一致,均为中更新世。 相似文献
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郯庐断裂带东地堑边界断层在断裂带演化过程和现今构造格局中都是重要断层,对该边界断层的第四纪活动性研究有助于了解郯庐断裂带的演化历史和地震活动性,而有关该边界断层第四纪活动性研究较少且至今尚无定论。本文通过浅层地震勘探和钻孔联合剖面相结合的方法,针对郯庐断裂带江苏段东地堑两边界断层开展系统的断层第四纪活动性研究,结果显示,昌邑-大店断裂(F_1)第四纪以来未见构造运动证据,白芬子-浮来山断裂(F_2)在第四纪早期曾发生有关活动,晚更新世以来未见活动迹象。 相似文献
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《地震地质》2017,(2)
以往对郯庐断裂带沂沭段各条断层第四纪活动性研究工作都集中在有历史地震记录的东地堑断层,而对断裂带西地堑断层却极少涉及,仅有的关于西地堑2条断层活动性的研究也至今没有定论。针对沂沭断裂带南段西地堑2条断层开展系统的浅层地震勘探和钻孔联合剖面相结合的研究,明确了鄌郚-葛沟断裂(F4)可能是第四纪早期断裂,而活动性较强的沂水-汤头断裂(F3)属于晚更新世活动断裂,其最新1次活动时间发生在距今(91.2±4.4)~(97.0±4.8)ka。结合断裂带其他断层的最新研究成果,对比东、西地堑活动断层最新活动时间,揭示出沂沭断裂带南段晚第四纪活动是断裂带对来自两侧应力的构造响应。沂水-汤头断裂可能是该区域未来中强地震的潜在发震构造。 相似文献
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祁连山-河西走廊地区断裂活动性评价 总被引：3，自引：0，他引：3
在震源机制解及构造应力场分析的基础上,定义了断层活动度、断层能动度的计算公式,进一步对祁连山-河西走廊地区的主要活动断裂进行了活动性评价,取得了较好的结果。 相似文献
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Holocene slip rate and paleoearthquake records of the Salt Lake segment of the Northern Zhongtiaoshan Fault,Shanxi Province 总被引：1，自引：0，他引：1
The Northern Zhongtiaoshan Fault is a major deep fault at the southern margin of the Yuncheng Basin. There have been few studies on the fault, and the historical earthquakes are few and weak. However, the intensity of activity on the fault should never be underestimated. Through interpretations of aerial images, topography measurements and excavation of trenches, this paper studied the fault distribution, the surface deformation and the activity of the normal fault south of Salt Lake near the city of Yuncheng. By tracing faults in the three trenches, it was found that there had been at least three large paleoseismic events, at 1–3.5, 3.6–4.4 and 7.4–8.8 ka BP. Employing 14 C dating, we determined the same gravel layers in the uplifted side and downthrown side. Making differential Global Positioning System measurements of the vertical difference and topographic profile, we obtained the mean slip rate of the Northern Zhongtiaoshan Fault since 24.7 ka BP(0.75±0.05 mm/a). Using the results of relevant studies, we calculated the possible vertical fault displacement of one earthquake(2.35 m) and obtained the recurrence interval of characteristic earthquakes as 2940–3360 a after dividing the displacement by the mean slip rate. 相似文献
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LATE-QUATERNARY ACTIVITY OF THE YALAHE FAULT OF THE XIANSHUIHE FAULT ZONE,EASTERN MARGIN OF THE TIBET PLATEAU 
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下载免费PDF全文 LIANG Ming-jian CHEN Li-chun RAN Yong-kang LI Yan-bao WANG Dong GAO Shuai-po HAN Ming-ming ZENG Di 《地震地质》1979,42(2):513-525
Complex geometrical structures on strike-slip faults would likely affect fault behavior such as strain accumulation and distribution, seismic rupture process, etc. The Xianshuihe Fault has been considered to be a Holocene active strike-slip fault with a high horizontal slip rate along the eastern margin of the Tibetan plateau. During the past 300 years, the Xianshuihe Fault produced 8 earthquakes with magnitude≥7 along the whole fault and showed strong activities of large earthquakes. Taking the Huiyuansi Basin as a structure boundary, the northwestern and southeastern segments of the Xianshuihe Fault show different characteristics. The northwestern segment, consisting of the Luhuo, Daofu and Qianning sections, shows a left-stepping en echelon pattern by simple fault strands. However, the southeastern segment(Huiyuansi-Kangding segment)has a complex structure and is divided into three sub-faults: the Yalahe, Selaha and Zheduotang Faults. To the south of Kangding County, the Moxi segment of the Xianshuihe Fault shows a simple structure. The previous studies suggest that the three sub-faults(the Yalahe, Selaha and Zheduotang Faults of the Huiyuansi-Kangding segment)unevenly distribute the strain of the northwestern segment of the Xianshuihe Fault. However, the disagreement of the new activity of the Yalahe Fault limits the understanding of the strain distribution model of the Huiyuansi-Kangding segment. Most scholars believed that the Yalahe Fault is a Holocene active fault. However, Zhang et al.(2017)used low-temperature thermochronology to study the cooling history of the Gongga rock mass, and suggested that the Yalahe Fault is now inactive and the latest activity of the Xianshuihe Fault has moved westward over the Selaha Fault. The Yalahe Fault is the only segment of the Xianshuihe Fault that lacks records of the strong historical earthquakes. Moreover, the Yalahe Fault is located in the alpine valley area, and the previous traffic conditions were very bad. Thus, the previous research on fault activity of the fault relied mainly on the interpretation of remote sensing, and the uncertainty was relatively large. Through remote sensing and field investigation, we found the geological and geomorphological evidence for Holocene activity of the Yalahe Fault. Moreover, we found a well-preserved seismic surface rupture zone with a length of about 10km near the Yariacuo and the co-seismic offsets of the earthquake are about 2.5~3.5m. In addition, we also advance the new active fault track of the Yalahe Fault to Yala Town near Kangding County. In Wangmu and Yala Town, we found the geological evidence for the latest fault activity that the Holocene alluvial fans were dislocated by the fault. These evidences suggest that the Yalahe Fault is a Holocene active fault, and has the seismogenic tectonic condition to produce a large earthquake, just like the Selaha and Zheduotang Faults. These also provide seismic geological evidence for the strain distribution model of the Kangding-Huiyuansi segment of the Xianshuihe Fault. 相似文献
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THE STRUCTURAL CHARACTERISTICS OF PANGUSI-XINXIANG FAULT IN THE SOUTHERN MARGIN OF TAIHANG MOUNTAINS 下载免费PDF全文
下载免费PDF全文 Pangusi-Xinxiang Fault is a great-scale, deep-incising buried active fault in the southern margin of the Taihang Mountains. In order to find out the location, characteristics, structure and activities of Pangusi-Xinxiang Fault, shallow reflection profiles with six lines crossing the buried faults were carried out. In this paper, based on the high-resolution seismic data acquisition technology and high-precision processing technology, we obtained clear images of underground structures. The results show that Pangusi-Xinxiang Fault is a near EW-trending Quaternary active fault and its structural features are different in different segment. The middle part of the fault behaves as a south-dipping normal fault and controls the north boundary of Jiyuan sag; The eastern part of the fault is a north-dipping normal fault and a dividing line of Wuzhi uplift and Xiuwu sag. The shallow seismic profiles reveal that the up-breakpoint of the Pangusi-Xinxiang Fault is at depth of 60~70m, which offsets the lower strata of upper Pleistocene. We infer that the activity time of this fault is in the lower strata of late Pleistocene. In this study, not only the location and characteristics of Pangusi-Xinxiang Fault are determined, but also the reliable geological and seismological evidences for the fault activity estimation are provided. 相似文献
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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
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海河隐伏活断层探测中土壤气氡和气汞测量及其结果 总被引：12，自引：0，他引：12
在海河隐伏断裂的探测中,利用FD-3017RaA测氡仪和XG-4型测汞仪开展了土壤气氡和土壤气汞的测量工作。根据12条断层气测线的测量结果,结合人工地震探测资料,对断层气异常位置与断层位置的关系进行了分析;运用断层气异常强度与断层活动性的关系对海河断裂的活动性进行了研究,给出了海河断裂天津段的位置和活动性分段。研究结果表明,断层气方法不仅能给出断层的初步位置,而且能够用于断层的活动性初步分段,但断层气方法所给出的断层位置应是一个条带。经与人工地震探测结果对比分析,断裂位于这个条带内;根据土壤气氡测量结果,可将海河断裂分为东、西两段,且东段的活动性要强于西段。这种强、弱之分仅是一种相对结果,在判定断层是否为活断层方面还存在一定困难 相似文献
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Existing achievements about Baotou Fault demonstrate it as a buried eastern boundary of the Baiyanhua Basin in Hetao active fault subsidence zone,striking NE.More data is needed to assess its activity.Located in the relay ramp between Wulashan Fault and Daqingshan Fault,Baotou Fault's activity is of great importance to discuss the linkage mode and the response to the earthquake of the adjacent fault.Also it is necessary to the knowledge of the characteristic of the seismic tectonic in local area.Recently it is prevalent to combine shallow seismic profile and composite drilling section to study the activity of the buried fault.Shallow seismic profile indicates that Baotou Fault is a normal fault,inclining to NW.The displacement of the Tg at 75m underground is 25m.Composite drilling section indicates that it is a growth fault,the up-break point of which is 45.6m underground and ends in brownish red clay strata of early Pleistocene.In comparison,the upper Late Pleistocene strata are out of the influences of the tectonic subsidence zone.Baotou Fault's activity is limited to the early Pleistocene. 相似文献
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THE DIFFERENCE OF DEPOSITION RATE IN THE BOREHOLES AT THE JUNCTION BETWEEN NANKOU-SUNHE FAULT AND HUANGZHUANG-GAOLIYING FAULT AND ITS RESPONSE TO FAULT ACTIVITY IN THE BEIJING AREA 下载免费PDF全文
下载免费PDF全文 ZHANG Lei BAI Ling-yan ZHAO Yong ZHANG Xiao-liang YANG Tian-shui CAI Xiang-min HE Fu-bing 《地震地质》2017,39(5):1048-1065
Beijing plain area has been always characterized by the tectonic subsidence movement since the Pliocene. Influenced and affected by the extensional tectonic environment, tensional normal faulting occurred on the buried NE-trending faults in this area, forming the "two uplifts and one sag" tectonic pattern. Since Quaternary, the Neocathaysian stress field caused the NW-directed tensional shear faulting, and two groups of active faults are developed. The NE-trending active faults include three major faults, namely, from west to east, the Huangzhuang-Gaoliying Fault, Shunyi Fault and Xiadian Fault. The NW-trending active faults include the Nankou-Sunke Fault, which strikes in the direction of NW320°~330°, with a total length of about 50km in the Beijing area. The northwestern segment of the fault dips SW, forming a NW-directed collapse zone, which controls the NW-directed Machikou Quaternary depression. The thickness of the Quaternary is more than 600 meters; the southeastern segment of the fault dips NE, with a small vertical throw between the two walls of the fault. Huangzhuang-Gaoliying Fault is a discontinuous buried active fault, a boundary line between the Beijing sag and Xishan tectonic uplift. In the Beijing area, it has a total length of 110km, striking NE, dipping SE, with a dip angle of about 50~80 degrees. It is a normal fault, with the maximum fault throw of more than 1 000m since the Tertiary. The fault was formed in the last phase of Yanshan movement and controls the Cretaceous, Paleogene, Neogene and Quaternary sediments.There are four holes drilled at the junction between Nankou-Sunhe Fault and Huangzhuang-Gaoliying Fault in Beijing area. The geographic coordinates of ZK17 is 40°5'51"N, 116°25'40"E, the hole depth is 416.6 meters. The geographic coordinates of ZK18 is 40°5'16"N, 116°25'32"E, the hole depth is 247.6 meters. The geographic coordinates of ZK19 is 40°5'32"N, 116°26'51"E, the hole depth is 500.9 meters. The geographic coordinates of ZK20 is 40°4'27"N, 116°26'30"E, the hole depth is 308.2 meters. The total number of paleomagnetism samples is 687, and 460 of them are selected for thermal demagnetization. Based on the magnetostratigraphic study and analysis on the characteristics of sedimentary rock assemblage and shallow dating data, Quaternary stratigraphic framework of drilling profiles is established. As the sedimentation rate of strata has a good response to the activity of the basin-controlling fault, we discussed the activity of target fault during the Quaternary by studying variations of deposition rate. The results show that the fault block in the junction between the Nankou-Sunhe Fault and the Huangzhuang-Gaoliying Fault is characteristic of obvious differential subsidence. The average deposition rate difference of fault-controlled stratum reflects the control of the neotectonic movement on the sediment distribution of different tectonic units. The activity of Nankou-Sunhe Fault shows the strong-weak alternating pattern from the early Pleistocene to Holocene. In the early Pleistocene the activity intensity of Huangzhuang-Gaoliying Fault is stronger than Nankou-Sunhe Fault. After the early Pleistocene the activity intensity of Nankou-Sunhe Fault is stronger than Huangzhuang-Gaoliying Fault. The activity of the two faults tends to consistent till the Holocene. 相似文献
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STUDY ON THE LATEST ACTIVITY OF WUYUNSHAN-HEFEI FAULT IN HEFEI BASIN,THE WESTERN BRANCH OF THE TANLU FAULT ZONE 下载免费PDF全文
下载免费PDF全文 ZHENG Ying-ping YANG Xiao-ping SHU Peng LU Shuo FANG Liang-hao SHI Jin-hu HUANG Xiong-nan LIU Chun-ru 《地震地质》1979,42(1):50-64
Tanlu fault zone is the largest strike-slip fault system in eastern China. Since it was discovered by aeromagnetics in 1960s, it has been widely concerned by scholars at home and abroad, and a lot of research has been done on its formation and evolution. At the same time, the Tanlu fault zone is also the main seismic structural zone in China, with an obvious characteristic of segmentation of seismicity. Major earthquakes are mostly concentrated in the Bohai section and Weifang-Jiashan section. For example, the largest earthquake occurring in the Bohai section is M7.4 earthquake, and the largest earthquake occurring in the Weifang-Jiashan section is M8.5 earthquake. Therefore, the research on the active structure of the Tanlu fault zone is mainly concentrated in these two sections. With the deepening of research, some scholars carried out a lot of research on the middle section of Tanlu fault zone, which is distributed in Shandong and northern Jiangsu Province, including five nearly parallel fault systems, i.e. Changyi-Dadian Fault(F1), Baifenzi-Fulaishan Fault(F2), Yishui-Tangtou Fault(F3), Tangwu-Gegou Fault(F4) and Anqiu-Juxian Fault(F5). They find that the faults F3 and F5 are still active since the late Quaternary. In recent years, we have got a further understanding of the geometric distribution, active age and active nature of Fault F5, and found that it is still active in Holocene. At the same time, the latest research on the extension of F5 into Anhui suggests that there is a late Pleistocene-Holocene fault existing near the Huaihe River in Anhui Province.
The Tanlu fault zone extends into Anhui Province and the extension section is completely buried, especially in the Hefei Basin south of Dingyuan. At present, there is little research on the activity of this fault segment, and it is very difficult to study its geometric structure and active nature, and even whether the fault exists has not been clear. Precisely determining the distribution, active properties and the latest active time of the hidden faults under urban areas is of great significance not only for studying the rupture behavior and segmentation characteristics of the southern section of the Tanlu fault zone, but also for providing important basis for urban seismic fortification. By using the method of shallow seismic prospecting and the combined drilling geological section, this paper carries out a detailed exploration and research on the Wuyunshan-Hefei Fault, the west branch fault of Tanlu fault zone buried in Hefei Basin. Four shallow seismic prospecting lines and two rows of joint borehole profiles are laid across the fault in Hefei urban area from north to south. Using 14C, OSL and ESR dating methods, ages of 34 samples of borehole stratigraphic profiles are obtained. The results show that the youngest stratum dislocated by the Wuyunshan-Hefei Fault is the Mesopleistocene blue-gray clay layer, and its activity is characterized by reverse faulting, with a maximum vertical offset of 2.4m. The latest active age is late Mesopleistocene, and the depth of the shallowest upper breaking point is 17m. This study confirms that the west branch of Tanlu fault zone cuts through Hefei Basin and is still active since Quaternary. Its latest activity age in Hefei Basin is late of Middle Pleistocene, and the latest activity is characterized by thrusting. The research results enrich the understanding of the overall activity of Tanlu fault zone in the buried section of Hefei Basin and provide reliable basic data for earthquake monitoring, prediction and earthquake damage prevention in Anhui Province. 相似文献
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断层的近代位错必将在地貌形态上留下深刻的印记,因而凭借断错地貌现象有可能得到关于活断层上地震活动性的重要信息。鲜水河断裂带上的断错地貌现象表明,断层以间歇性的地震滑动为特征,而且服从于大小相当的地震在原地重复发生的特征地震模式。断错水系的演化图象则进一步提供了在一定时段内,同一地点滑动速率基本稳定的线索。于是,可以把断错地貌的研究作为地震活动性研究的重要手段 相似文献
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五峰山-西来桥断裂和丹徒-建山断裂是镇江地区2条主要的NW向断裂,可能与镇江多次破坏性地震相关。文中通过浅层地震勘探和钻孔联合剖面探测方法,对五峰山-西来桥断裂和丹徒-建山断裂的展布特征及第四纪活动性进行了系统研究。五峰山-西来桥断裂在浅层地震剖面上倾向NE,倾角约为60°,断距约为5~9m,以正断活动为主;大路镇场地上,该断裂断错的最新地层为中更新统底部,位错量为2m,判断五峰山-西来桥断裂的最新活动时代为中更新世早期。丹徒-建山断裂在浅层地震剖面上倾向SW,倾角约为50°~55°,断距约为2~7m,以正断活动为主;访仙镇场地上,中更新统之上的地层没有被断错的迹象,中更新统底部可能被断层影响,判断丹徒-建山断裂的最新活动时代为早更新世—中更新世早期。 相似文献