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《地震地质》2016,(1)
渭河断裂杨家村—窑店段西起杨家村,经魏家泉、金家庄、东耳村、陈家台,到达窑店,走向NE,倾向S,长约33km,为同生正断层,沿渭河北岸I级、Ⅱ级、Ⅲ级阶地前、后缘展布。遥感解译、浅层地震探测、探槽、钻孔联合剖面结果表明,渭河断裂杨家村—窑店段在咸阳附近的渭河北岸阶地表现为断层陡坎,与NE向阶地坎重合;断裂在晚更新世晚期至全新世可能仍有活动。渭河断裂杨家村—窑店段自(46.0±3.3)ka以来断距较大,在11.0~16.5m之间;垂直滑动速率在0.34~0.45mm/a之间;断裂最新活动时间约为2.0ka BP。金家庄左阶斜裂区将渭河断裂杨家村—窑店段划分为杨家村—金家庄段和东耳村—窑店段。 相似文献
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河流阶地演化与走滑断裂滑动速率 总被引：24，自引：9，他引：15
断裂滑动速率是活动构造定量研究的最重要参数之一,不仅可以直接应用于活动构造的地震危险性预测和工程场地的地震安全性评价,还为地球动力学研究提供不可缺少的重要信息。原理上,断裂滑动速率可以用总位移量除以其累积时间而获得,但准确地确定断裂滑动速率并不是一件容易的事情,不同方法和研究者测定的同一条断裂的滑动速率可以相差3倍。文中通过对河流基座阶地演化及其对走滑断裂错动响应过程的分析发现,当一条山前河流切入河漫滩使其废弃形成阶地后,断裂的走滑位移使得河流两侧的阶地陡坎都遭到错动,其中一侧的下游阶地陡坎被错入河道而遭到河流的侵蚀,另一侧的下游阶地陡坎被错离河道,受到河流上游右侧地貌的保护而免遭侵蚀。因此,被错离河道一侧的阶地陡坎的位移在上阶地形成时就开始积累,阶地面的暴露年龄相当于位移累积的起始年代。另外,被错离河道一侧的阶地陡坎在下阶地停止侧蚀(可能同时开始接受沉积)时就开始累积位移,下阶地的初始沉积年代也代表阶地陡坎位移开始累积的时间。当然,如果能够获得被位移阶地陡坎的上下阶地年龄,就更能够把滑动速率限定在可靠的范围之内。在上述分析的基础上,提出3种利用河流阶地确定走滑断裂滑动速率的方法:第一是利用上下阶地年龄限定 相似文献
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热水 -日月山断裂带是发育在青藏高原东北缘柴达木 -祁连活动地块内部的 1条重要的NNW向逆 -右旋走滑活动断裂带 ,长约 183km。断裂由 4条不连续的次级断裂段右阶羽列而成 ,阶距 2～ 3km左右 ,在不连续部位形成拉分区。主断裂两端则形成帚状分叉。断裂活动形成了一系列山脊、冲沟和阶地等右旋断错微地貌 ,其中Ⅰ级阶地右旋断错约 8～ 11m ,Ⅱ级阶地右旋断错约 35m。同时沿断裂带还形成了许多断层陡坎 ,Ⅰ级阶地或洪积台地上断层陡坎高约 0 .5～ 1m ,最高达 2 .8m ,Ⅱ级阶地或台地上的断层陡坎高约 2 .5～ 3m ,最高达 4～ 5m。根据相应的阶地年代 ,计算得到断裂带全新世以来的平均水平滑动速率为 3 16mm/a ,垂直滑动速率为 0 .83mm/a 相似文献
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海秀断裂近东西向展布于海口市中心,准确厘定其几何位置和最新活动特征对科学评价海口市地震危险性、地震构造和地球动力学具有重要科学意义。本文采用野外地质调查、微地貌测量、浅层人工地震勘探和钻孔联合剖面探测相结合的方法,针对前人确定的海口市中心城区全新世活动海秀断裂,分别在5个典型地点进行详细研究。首先,通过野外地质调查和微地貌测量,得到其中3个地点的地貌陡坎最大垂直落差为11～15 m;其次,跨地貌陡坎和海秀断裂实施了5条浅层人工地震勘探,结果显示,海秀断裂在地震剖面上反映微弱,断错特征不明显,推测断裂总体活动性较低。为验证该断裂的准确位置和最新活动特征,分别在海港路和人民公园开展了钻孔联合剖面探测,通过详细对比分析钻孔揭示的地层序列和地层年代,未发现因断裂活动导致的构造变形迹象,认为海秀断裂上新世以来在探测深度范围内不存在,海口市现有地貌陡坎应为海蚀阶地坎,可排除断裂陡坎的可能。原断裂沿线区域地震危险性被错误高估,经济建设和发展规划可不考虑该断裂的避让问题。 相似文献
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根据对北京平谷三河地区地表陡坎的观察比较,研究了河流侵蚀陡坎与断层陡坎的微地貌形态差异。河流侵蚀形成陡坎的方向追随河流的冲沟方向,具不稳定性,并且陡坎的倾向沿河对称。断层陡坎的展布不受河流方向的影响,断层以倾向活动为主时,陡坎两盘的运动方向稳定。研究结果表明,平谷地区的地表陡坎是河流侵蚀陡坎。同时,还从构造地貌学与地层沉积学的角度,分析了平原区河流侵蚀沉积与断层断错沉积的特征,指出平谷地区的浅层人工地震探测及浅钻资料存在两种解释的可能性 相似文献
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宁夏卫宁北山位于青藏高原、阿拉善和鄂尔多斯3大活动地块的交汇地带,查清该地区的活断层对厘清活动地块边界和规划中卫工业园区布局均具有重要意义。采用浅层地震勘探、钻孔联合剖面探测及槽探等手段,针对卫宁北山南缘推测断层开展综合探测,以便查清该断层展布情况和地层断错特征,并结合区域地层时代对比,初步鉴定已探明断层的活动性。结果表明：前人推测的地貌陡坎之下的卫宁北山南缘正断层并不存在,而在卫宁北山南缘地貌陡坎偏北基岩内发育一条逆冲断层,浅层地震勘探剖面揭示该断层上断点埋深35～40 m,钻孔联合剖面探测和槽探发现断层错断了石炭系和新近系,但未错断上覆的上更新统,表明该断层不是活动断层;另外,浅层地震剖面揭示在中卫盆地内部还发育一条北西西向的隐伏正断层,上断点埋深约60 m,但也未错动晚更新世以来地层,因而推测该断层不存在晚第四纪活动性。 相似文献
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骊山山前断裂华清池以西段晚更新世以来的活动性 总被引：1，自引：0，他引：1
骊山山前断裂位于骊山北侧,其华清池以西段向渭河盆地延伸,该断裂的几何展布和活动习性是准确认识渭河盆地东部区域地震构造及地震安全性评价的重要依据。跨断裂推测位置布设高密度电法、人工浅层地震及联合钻孔剖面并通过探槽开挖等多种手段进行探测,所得结果显示,华清池以西段的走向由其西段的近EW向变为N60°W,断裂由2支次级正断层构成,倾向NE,倾角约75°。其中,南支次级断层自晚更新世以来没有明显的活动证据,北支次级断层最新活动时代为全新世。人工浅层地震探测揭示断裂附近的地层产状整体倾向S,推测与骊山断块自新生代以来向S掀斜运动有关;联合钻探剖面揭示北支断层自中更新世晚期以来古土壤层S_2断错位移量约10m;晚更新世早期以来古土壤层S_1垂直错距最大约7. 8m。探槽剖面揭示西延段断裂自马兰黄土沉积((32 170±530) Cal a BP)以来至少发生过3次古地震事件,并造成马兰黄土最大总错距约3. 0m。其中,断裂最新一次活动使全新世早期的黄土层L_0((8 630±20) Cal a BP)产生了约0. 9m的垂直错距,并在全新统黑垆土地层S_0((4 390±20) Cal a BP)中形成了明显的张裂缝。最终分析得到骊山山前断裂西延段全新世((8 630±20) Cal a BP)以来的垂直活动速率为0. 11～0. 19mm/a,推测单次事件产生的垂直位错量约0. 9m。 相似文献
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阳关断裂位于青藏高原北部阿尔金断裂系向北扩展的前缘位置，对其几何学和运动学的深入研究，有助于理解青藏高原向大陆内部扩展的机制。文章通过卫星影像解译、探槽开挖、差分GPS及无人机测量等对阳关断裂开展了详细研究。结果显示：阳关断裂东段发育多条正反向断层陡坎，断层陡坎高度在0.4～8 m之间，平均约2.2 m,探槽揭示断裂倾角约60°,形成高角度逆断层，局部发育正断层；西段断裂向北西前缘扩展，形成一组弧形分布的断层陡坎，陡坎高度多在0.9～2.4 m,平均约1.9 m。同时自南向北，逆冲断层陡坎形态由多级陡坎转为单一陡坎。对探槽剖面分析，显示断裂断错晚更新世冲洪积砾石层，发育的断层倾角较缓，以低角度逆冲为主要特征，约26°,有的甚至沿地层向前推覆。结合前人的研究成果，阳关断裂可能为本区阿尔金向北扩展的北边界，与三危山断裂共同协调吸收了阿尔金断裂东段的部分应变量。 相似文献
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郯庐断裂带是中国东部最主要的一条活动断裂带。在该断裂带中部,沂沭断裂东地堑的潍坊—嘉山段中发育了1条长360km的全新世活动断裂带(F5),在该全新世断裂带的北段和中段分别发生了公元70年的安丘地震和公元1668年的郯城地震。2003年底我们考察沭河断裂带时,在莒县境内发现了1条长约7km的地震破裂带,作为活动断层应该归属于F5断裂带,但其是一条独立的地震破裂段还是归属于1668年郯城8.5级地震破裂带有待于进一步的研究。尽管如此,探槽揭示出的上覆未经破坏的地层的14C年代表明,该破裂带在(2140±190)aBP以来没有过活动,因此我们认为其作为1条独立破裂段的可能性较大 相似文献
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DISTRIBUTION OF YANGJIA VILLAGE-YAODIAN SECTION OF WEIHE FAULT AND THE CHARACTERISTICS OF ITS LATE QUATERNARY ACTIVITY 
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下载免费PDF全文 The Yangjia Village-Yaodian segment of Weihe Fault, starting from Yangjia Village in the west, passing through Weijiaquan, Jinjiazhuang, Donger Village, Chenjiatai to Yaodian, occurs as a NE-striking fault dipping south with a total length of 33 kilometers. As a syn-depositional normal fault, it extends along the leading and trail edge of T1, T2 and T3 terrace at the northern bank of Weihe River. Results of remote sensing interpretation, shallow seismic exploration, exploratory trench, and drilling show that the Yangjia Village-Yaodian section of Weihe Fault manifests as fault scarps, overlapping with the NE-extending terrace scarp at the northern bank of Weihe River. Weihe Fault broke the T1 that can be distinguished on the shallow seismic profile and multiple profiles with broken signs from T1 to the ground, which is the same with the cracks through the Han Tomb at the top of the exploratory trench in Yangjia Village. It shows that the fault may still be active from the late Pleistocene to Holocene. Through composite drilling section and the analysis of exploratory trench, there is no significant difference in activity between the Yangjia Village-Jinjiazhuang and Donger Village-Yaodian section. This segment has experienced a large displacement event since (46.0±3.3)ka BP, approximately 11.0~16.5m, with a vertical slip rate of 0.34~0.45mm/a. The most recent activity occurred approximately around 2.0ka BP. The left-step en echelon fracture zone at Jingjiazhuang separates this section into two minor ones, Yangjia Village-Jinjiazhuang section and Donger Villag-Yaodian section. Yangjia Village-Yaodian section in Weihe Fault and Yaodian-Zhangjiawan section which was found out in the Xi'an active fault detection and seismic risk assessment project can be combined into the Yangjia Village-Zhangjiawan section. 相似文献
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临潼-长安断裂带晚第四纪以来的活动性 总被引：1，自引：0，他引：1
对临潼-长安断裂带进行了详细的野外调查,以期掌握其最新活动年代和第四纪以来的活动特征。该断裂总体走向NE,以张性垂直运动为主,断面明显错断了黄土中的第1层古土壤S1,说明其晚更新世以来仍在活动,并且北段和中段的活动性比南段强,但是错距大多<2m,滑动速率较小,考虑到临潼-长安断裂带由多条次级断层组成,其整体活动性应该比我们计算得到的局部断层滑动速率大得多。断层错距自上而下成递增趋势,并且根据不同地层年代计算出的滑动速率基本一致,因此该断裂带自中更新世晚期以来极可能以垂向蠕滑活动为主 相似文献
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THE CRUSTAL SHALLOW STRUCTURES AND FAULT ACTIVITY DETECTION IN XINYI SECTION OF TAN-LU FAULT ZONE 下载免费PDF全文
下载免费PDF全文 GU Qin-ping XU Han-gang YAN Yun-xiang ZHAO Qi-guang LI Li-mei MENG Ke YANG Hao WANG Jin-yan JIANG Xin MA Dong-wei 《地震地质》1979,42(4):825-843
The Tan-Lu fault zone is the largest active tectonic zone in eastern China, with a complex history of formation and evolution, and it has a very important control effect on the regional structure, magmatic activity, the formation and distribution of mineral resources and modern seismic activity in eastern China. Xinyi City has a very important position as a segmental node in the Shandong and Suwan sections of the Tan-Lu fault zone. Predecessors have conducted research on the spatial distribution, occurrence and activity characteristics of the shallow crustal faults in the Suqian section of the Tan-Lu belt, and have obtained some new scientific understandings and results. However, due to different research objectives or limitations of research methods, previous researches have either focused on the deep crustal structure, or targeted on the Suqian section or other regions. However, the structural style and deep-shallow structural association characteristics of Xinyi section of Tan-Lu belt have not been well illustrated, nor its activity and spatial distribution have been systematically studied. In order to investigate the shallow crustal structure features, the fault activities, the spatial distribution and the relationship between deep and shallow structures of the Xinyi section of the Tan-Lu Fault, we used a method combining mid-deep/shallow seismic reflection exploration and first-break wave imaging. Firstly, a mid-deep seismic reflection profile with a length of 33km and a coverage number greater than 30 was completed in the south of Xinyi City. At the same time, using the first arrival wave on the common shot record, the tomographic study of the shallow crust structure was carried out. Secondly, three shallow seismic reflection profiles and one refraction tomography profile with high resolution across faults were presented. The results show that the Xinyi section of Tan-Lu fault zone is a fault zone composed of five concealed main faults, with a structural pattern of “two grabens sandwiched by a barrier”. The five main faults reveal more clearly the structural style of “one base between two cuts” of the Tan-Lu fault zone. From west to east, the distribution is as follows: on the west side, there are two high-angle faults, F4 and F3, with a slot-shaped fault block falling in the middle, forming the western graben. In the middle, F3 and F2, two normal faults with opposite dip directions, are bounded and the middle discontinuity disk rises relatively to form a barrier. On the east side, F2 and F1, two conjugate high-angle faults, constitute the eastern graben. The mid-deep and shallow seismic reflection profiles indicate that the main faults of the Xinyi section of Tan-Lu fault zone have a consistent upper-lower relationship and obvious Quaternary activities, which play a significant role in controlling the characteristics of graben-barrier structure and thickness of Cenozoic strata. The shape of the reflective interface of the stratum and the characteristics of the shallow part of the fault revealed by shallow seismic reflection profiles are clear. The Mohe-Lingcheng Fault, Xinyi-Xindian Fault, Malingshan-Chonggangshan Fault and Shanzuokou-Sihong Fault not only broke the top surface of the bedrock, but also are hidden active faults since Quaternary, especially the Malingshan-Chonggangshan Fault which shows strong activity characteristics of Holocene. The results of this paper provide a seismological basis for an in-depth understanding of the deep dynamics process of Xinyi City and its surrounding areas, and for studying the deep-shallow tectonic association and its activity in the the Xinyi section of the Tan-Lu Fault. 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 下载免费PDF全文
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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华南滨海断裂带地震危险性的数学模拟 总被引：5，自引：1，他引：5
华南滨海断裂带是南海北部规模巨大的活动断裂，其地震危险性的确定将为地震几地震工程提供地质背景依据，应用二维有限元分析和正交设计法反演南海北部及其今近地区的构造应力场，探讨可能发震的危险地段。研究结果表明，滨海断裂带的某些地段，尤其是滨海断裂带被ＮＷ向断裂切割的部位有一定的地震危险性。南海北部地区最主要的地震威胁来自巴士系断裂带和珠江口盆地南缘的ＮＷＷ向断裂带，对华南滨海断理解带潜在的地震危险性不宜 相似文献
19.
汤西断裂的断层围陷波初步研究 总被引：6，自引：0，他引：6
作为断层围陷波方法在城市活断层探测中的首次尝试,我们针对太行山山前断裂带南段的汤西断裂开展了爆炸震源的观测试验。运用数字滤波和频谱分析等技术,由地震记录图分离出了断层围陷波。根据2横测线的观测结果,可确定断层的位置,并可推测断层在该处宽度为200～300m。破裂面较宽,可能与其张性特征有关。分频道地震图显示,断层围陷波具有正频散现象,其低频分量传播较快。这表明断层围陷波是一种面波,可利用其频散规律研究断裂带内介质的物理性质。这次的观测结果也表明,断层围陷波并不局限于新破裂带,在老断层中也能形成和传播。事实上,只要断层带内外的介质在物理性质上有较大的差异,均能产生沿断层传播的围陷波。在城市活断层探测中,断层围陷波的方法具有非常独特的优越性 相似文献
20.
龙门山断裂带晚第四纪活动性分段的初步研究 总被引：21，自引：3，他引：21
NE向展布于松潘-甘孜造山带与扬子陆块之间的龙门山断裂带,是由后山断裂等4条主干断裂及其控制的冲断构造岩片组成的具前展式发育特点的推覆构造带。它形成于印支运动,此后多次活动,第四纪以来活动强烈,但不同地段活动程度具有明显的非均一性。根据地貌、地质构造、布格重力异常和地震活动等资料的综合分析研究认为:1)以位于虎牙—北川—安县一线的近SN向虎牙断裂和擂东断裂为界划分出断裂带西南段和东北段,其活动性迥然不同,西南段晚更新世以来活动强烈,中小地震频繁;东北段第四纪活动微弱,仅偶有小震分布。2)在青藏高原被挤压隆升和块体侧向滑移的作用下,川青地块向SEE滑动,使它东缘发育的岷山隆起与被其截切的龙门山断裂带西南段一起构成了川青地块东部的活动边界,而龙门山断裂带东北段则被遗弃 相似文献