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1.
断层泥粒度成分的分形研究   总被引:10,自引:3,他引:10  
易顺民  唐辉明 《地震地质》1995,17(2):185-191
用分形理论分析了断层泥粒度成分的分形结构特征,其分维在2~3之间,平均值为2.8左右。分维可作为定量描述断层泥粒度成分的参数,分维值高的断层泥,自组织程度高,其形成演化处于高级阶段。探讨了断层泥的分维及其物理力学性质指标和断层运动特征的关系  相似文献   

2.
断层泥的分形研究   总被引:1,自引:0,他引:1       下载免费PDF全文
邵顺妹  邹谨敞 《地震学报》1996,18(3):376-381
介绍了利用光学显微镜和电子显微镜对采自西秦岭北缘活动断裂带的天然断层泥进行分形研究的程序和结果,得到该断裂断层泥的分维数D=2.5940.122(二维截面D=1.5940.122),并测得该断裂带断层泥分维上限平均粒径为9.6~19.2 mm.研究结果表明,该断裂带断层泥具有分形特征,断层面的粘滑摩擦特征位移参数可由分维上限确定.文中还讨论了断层泥分形研究对地震断层的研究意义.   相似文献   

3.
王华林  耿杰 《中国地震》1996,12(3):307-315
利用岩石碎裂数目的分形理论,分析,计算了沂沭断裂带及其西侧北西向断裂的断层泥粒度成分的分维值,讨论了断层泥粒度成分分维的地震地质意义,研究结果表明,沂沭断裂带内的断裂活动的强度大于北西向断裂活动强度;F2是沂沭断裂带中活动最强的一条断裂,断层泥粒度成分分维值可作为表征断裂活动时代,破裂形式和断层泥形成斫代等的参量;分维值还与断层泥的母岩,厚度,粘土矿物含量和所处的断裂部位等相关。  相似文献   

4.
用筛选法和悬浮法相结合的方法对采自西秦岭北缘断裂带东段和海原断裂带西段的天然断层泥进行了粒度分布和分形研究。 研究结果表明 这2条断裂带断层泥粒度组成为粗粒级(Φ<4)含量高,细粒级(Φ≥4)含量低; 断层泥分维值分别为2.594±0.122和2.654±0.112,分维上限分别为2 cm和1 cm。  相似文献   

5.
介绍了西秦岭北缘断裂带东段和海原断裂带西段的天然断层泥的分形方法和结果,并对断层泥的粒度分布特征与断层运动特性的关系进行了探讨。  相似文献   

6.
陈建业  杨晓松 《地震地质》2014,36(2):368-379
断层岩的粒度分布包含岩石破裂机制、摩擦性质和地震能量分配等重要信息。筛分-称重和激光测量是分析断层岩三维粒度的2种有效方法,但每一种方法的测量范围仅有3个量级,难以全面反映断层岩的粒度分布特征。利用上述2种方法对汶川地震断层滑动带上的断层岩(简称断层岩)的粒度分布进行了测量,粒径测量范围从0.2μm至16mm,跨度达到5个数量级。结果显示:1)存在临界粒径dc(0.95~1.90μm)。粒度大于和小于dc的颗粒满足不同的颗粒数(Nd)-粒径(d)分布关系,表明该断层岩的粒径分布不具有自相似性特征。2)利用粒度大于dc的颗粒计算出的分形维数与断层岩类型有很好的相关性,即断层带边缘的角砾岩的平均分形维数为2.6,核部压碎角砾岩的平均分形维数约为3.0,中心断层泥的分形维数约为3.5。粒径小于dc的颗粒的分形维数为1.7~2.1。分形维数的突变反映出断层破裂机制的复杂性,即在不同的粒度域,岩石的破裂机制不尽相同。3)依据粒度分析结果,估算出汶川地震断层泥的单位破裂能(Es)为0.63MJ/m2。  相似文献   

7.
本文利用box—Counting法讨论了新疆各主要断裂带的几何分形,得出了各断裂带的分维值。结合区域构造及地震活动性特点,分析讨论了断层分形几何学在判定强震危险区方面的应用前景。结果表明,相应于较大的断层分维数,则对应于较强的地震活动水平;相应于较小的断层分维值,则对应于较弱的地震活动水平。一方面,断裂分维值较高的断裂带,其构造也较复杂。因而,断层分维有可能作为判定活动断裂带地震活动水平的一种特征物理量。  相似文献   

8.
通过对中国大陆及青藏高原、新疆、华北和东北各构造区的地震活动性的分析,论证了区域地震活动是一种自组织临界现象.利用分形理论中的粗视化网格法,研究了中国大陆以及各构造区断层系的分形特点和分形结构的跨尺度特征.开展了组构具有分形特点的沙堆模型实验.结合断裂力学理论,认为地震的自组织临界现象源于分形几何断层系的自组织临界性动力学过程,地震分维数和断层系分维数之间存在着一种正相关关系,明确了断层系分形和地震活动性分形之间的因果关系.在此基础上,提出了系统组构的分形是系统输出能量的分形的根源的观点,并进一步利用已有的观测资料进行了分析.最后,基于这个观点和区域断层分布可以通过常规的航卫片分析、地面调查和地质勘探等手段确定的事实,提出了利用断层的分维数与地震的分维数的相关关系,对区域地震的概率分布特征进行估计的观点,可为地震的预测预报提供参考.  相似文献   

9.
鲜水河断裂西北段的断层泥特征及其地震地质意义   总被引:21,自引:10,他引:11       下载免费PDF全文
对鲜水河断裂的断层泥样品进行原样的结构、构造和碎砾的显微构造、刻蚀形貌结构的观测统计,断层泥的粒度分析和分形研究,认为,断裂处于强烈的定向应力场作用之下,其运动方式是以粘滑运动为主,且晚更新世和全新世时期断裂仍有活动。从断层泥的粒度分布和分形分析可将断层分为:甘孜-格篓、格篓-恰叫、恰叫-乾宁3段,这与前人的地形变分析的分段结果相一致  相似文献   

10.
西秦岭北缘断裂带东段断层泥的粒度分布和显微构造特征   总被引:3,自引:0,他引:3  
根据采集的天然断层泥样品,对西秦岭北缘活动断裂带东段的断层泥首次进行了粒度分布和显微构造特征的实验研究。研究结果表明,该断裂带以粘滑运动为主,兼有蠕滑活动,并具张性扭动特征。  相似文献   

11.
断块运动与活断层分段   总被引:3,自引:3,他引:3  
断层作为断块的边界,其活动特征和断块运动密切相关。通过分析断块运动类型与断层活动及其分段的关系,以及断块运动与构造障碍的关系,论述了断块运动研究在活断层分段中的作用  相似文献   

12.
概述了古地震断层和能动断层活动年代测定研究的现状和进展。提出了应用多种测年方法对古地震断层和能动断层的最新活动年代的测定进行综合研究。指出了当前在断层活动年代的测定工作中存在的关键问题,同时也初步提出了今后改进的意见。  相似文献   

13.
The Longmenshan fault zone is located in eastern margin of Tibetan plateau and bounded on the east by Sichuan Basin, and tectonically the location is very important. It has a deep impact on the topography, geomorphology, geological structure and seismicity of southwestern China. It is primarily composed of multiple parallel thrust faults, namely, from northwest to southeast, the back-range, the central, the front-range and the piedmont hidden faults, respectively. The MS8.0 Wenchuan earthquake of 12th May 2008 ruptured the central and the front-range faults. But the earthquake didn't rupture the back-range fault. This shows that these two faults are both active in Holocene. But until now, we don't know exactly the activity of the back-range fault. The back-range fault consists of the Pingwu-Qingchuan Fault, the Wenchuan-Maoxian Fault and the Gengda-Longdong Fault. Through satellite image(Google Earth)interpretation, combining with field investigation, we preliminarily found out that five steps of alluvial platforms or terraces have been developed in Minjiang region along the Wenchuan-Maoxian Fault. T1 and T2 terraces are more continuous than T3, T4 and T5 terraces. Combining with the previous work, we discuss the formation ages of the terraces and conclude, analyze and summarize the existing researches about the terraces of Minjiang River. We constrain the ages of T1, T2, T3, T4 and T5 surfaces to 3~10ka BP,~20ka BP, 40~50ka BP, 60ka BP and 80ka BP, respectively. Combining with geomorphologic structural interpretation, measurements of the cross sections of the terraces by differential GPS and detailed site visits including terraces, gullies and other geologic landforms along the fault, we have reason to consider that the Wenchuan-Maoxian Fault was active between the formation age of T3 and T2 terrace, but inactive since T2 terrace formed. Its latest active period should be the middle and late time of late Pleistocene, and there is no activity since the Holocene. Combining with the knowledge that the central and the front-range faults are both Quaternary active faults, the activity of Longmenshan fault zone should have shifted to the central and the front-range faults which are closer to the basin, this indicates that the Longmenshan thrust belt fits the "Piggyback Type" to some extent.  相似文献   

14.
晁洪太  李家灵 《地震研究》1997,20(2):218-226
郯庐断裂带潍坊-嘉山段全新世活断层由三个独立的破裂段组成。从各段的断错地貌,松散堆积物特征,断层本身的特点以及断层泥的显微构造标志看,各段具有共同的特点,就是主要粘滑运动为主,并在震后有蠕滑调整运动,各段具有断层闭锁→粘滑发震→震后调整→断层再次闭锁的发震模式,目前莒县-郯城段仍处于震后调整阶段,而安丘段和新沂-泗洪段由已处于断层闭锁的后期阶段,面临粘滑发震的危险。  相似文献   

15.
以山西地堑系罗云山山前断裂的基岩断层面为例,用陆基Li DAR扫描获取了断层面形貌学数据,采用各向同性变差函数法计算了断层面形貌的分维值。结果显示,断层面形貌在高度上具有显著的分带性,每个分带的特征分维值随断层面高度的增加呈阶跃式变化。分析认为这种形貌特征可能反映了断层面与多次地震相关的间歇式出露方式。分带高度指示了约3m和1m的2组同震倾滑位移量,各分带之间的分维值过渡带是断层面缓慢剥露的结果。与片麻岩区的断层面形貌学研究结果相比,灰岩断层面形貌学分维值随着暴露时间的增加而减小,2种岩性区的断层面分维值D与断层面高度H呈现类似镜像的关系,在气候构造条件大致相同的情况下,考虑为岩性差异的影响。  相似文献   

16.
塔什库尔干断裂带北段木吉河断层运动特征   总被引:1,自引:0,他引:1  
塔什库尔干断裂带是由多条运动性质不同的次级断层组成。该断裂带北段的木吉河断层运动特征以逆冲为主,兼有右旋走滑分量。该断层全长20km左右,全新世以来仍有较强活动,断错了全新世中晚期的地貌面,对吉如吉能沟西岸的阶地变形进行测量,得到Ⅰ、Ⅱ阶地的垂直断错量分为10m和14m左右。通过对变形阶地的年代测定,计算得到全新世中期以来,木吉河断层的平均垂直滑动速率为1.8—2.1mm/a,所造成的南北向地壳缩短为1.1~1.3mm/a。  相似文献   

17.
The NE-trending Xinyi-Lianjiang fault zone is a tectonic belt, located in the interior of the Yunkai uplift in the west of Guangdong Province, clamping the Lianjiang synclinorium and consisting of the eastern branch and the western branch. The southwestern segment of the eastern branch of Xinyi-Lianjiang fault zone, about 34km long, extends from the north of Guanqiao, through Lianjiang, to the north of Hengshan. However, it is still unclear about whether the segment extends to Jiuzhoujiang alluvial plain or not, which is in the southwest of Hengshan. If it does, what is about its fault activity? According to ‘Catalogue of the Modern Earthquakes of China’, two moderately strong earthquakes with magnitude 6.0 and 6.5 struck the Lianjiang region in 1605 AD. So it is necessary to acquire the knowledge about the activity of the segment fault, which is probably the corresponding seismogenic structure of the two destructive earthquakes. And the study on the fault activity of the segment can boost the research on seismotectonics of moderately strong earthquakes in Southeast China. In order to obtain the understanding of the existence of the buried fault of the southwestern segment, shallow seismic exploration profiles and composite borehole sections have been conducted. The results indicate its existence. Two shallow seismic exploration profiles show that buried depth of the upper breakpoints and vertical throw of the buried fault are 60m and 4~7m(L5-1 and L5-2 segment, the Hengshan section), 85m and 5~8m(L5-3 segment), 73m and 3~5m(Tiantouzai section), respectively and all of them suggest the buried fault has offset the base of the Quaternary strata. Two composite borehole sections reveal that the depth of the upper breakpoints and vertical throws of the buried segment are about 66m and 7.5m(Hengshan section) and 75m and 5m(Tiantouzai section), respectively. The drilling geological section in Hengshan reveals that the width of the fault could be up to 27m. Chronology data of Quaternary strata in the two drilling sections, obtained by means of electron spin resonance(ESR), suggest that the latest activity age of the buried fault of the southwestern segment is from late of early Pleistocene(Tiantouzai section) to early stage of middle Pleistocene(Hengshan section). Slip rates, obtained by Hengshan section and Tiantouzai section, are 0.1mm/a and 0.013mm/a, respectively. As shown by the fault profile located in a bedrock exposed region in Shajing, there are at least two stages of fault gouge and near-horizontal striation on the fault surface, indicating that the latest activity of the southwestern segment is characterized by strike-slip movement. Chronology data suggest that the age of the gouge formed in the later stage is(348±49) ka.  相似文献   

18.
The quantitative analysis of morphologic characteristics of bedrock fault surface is a useful approach to study faulting history and identify paleo-earthquake. It is an effective complement to trenching technique, specially to identifying paleo-earthquakes in a bedrock area where the trenching technique cannot be applied. This paper focuses on the Luoyunshan piedmont fault, which is an active normal fault extending along the eastern boundary of the Shanxi Graben, China. There are a lot of fault scarps along the fault zone, which supply plentiful samples to be selected to our research, that is, to study faulting history and identify paleo-earthquakes in bedrock area by the quantitative analysis of morphologic characteristics of fault surfaces. In this paper, we calculate the 2D fractal dimension of two bedrock fault surfaces on the Luoyunshan piedmont fault in the Shanxi Graben, China using the isotropic empirical variance function, which is a popular method in fractal geometry. Results indicate that the fractal dimension varies systematically with height above the base of the fault surface exposures, indicating segmentation of the fault surface morphology. The 2D fractal dimension on a fault surface shows a ‘stair-like’ vertical segmentation, which is consistent with the weathering band and suggests that those fault surfaces are outcropped due to periodic faulting earthquakes. However, compared to the results of gneiss obtained by the former researchers, the characteristic fractal value of limestone shows an opposite evolution trend. 1)The paleo-earthquake study of the bedrock fault surface can be used as a supplementary method to study the activity history of faults in specific geomorphological regions. It can be used to fill the gaps in the exploration of the paleo-earthquake method in the bedrock area, and then broaden the study of active faults in space and scope. The quantitative analysis of bedrock fault surface morphology is an effective method to study faulting history and identify paleo-earthquake. The quantitative feature analysis method of the bedrock fault surface is a cost-effective method for the study of paleo-earthquakes in the bedrock fault surface. The number of weathered bands and band height can be identified by the segment number and segment height of the characteristic fractal dimension, and then the paleoearthquake events and the co-seismic displacement can be determined; 2)The exposure of the fault surface of the Luoyunshan bedrock is affected and controlled by both fault activity and erosion. A strong fault activity(ruptured earthquake)forms a segment of fault surface which is equivalent to the vertical co-seismic displacement of the earthquake. After the segment is cropped out, it suffers from the same effect of weathering and erosion, and thus this segment has approximately the same fractal dimension. Multiple severe fault activities(ruptured earthquake)form multiple fault surface topography. The long-term erosion under weak hydrodynamic conditions at the base of the fault cliff between two adjacent fault activities(intermittent period)will form a gradual slow-connect region where the fractal dimension gradually changes with the height of the fault surface. Based on the segmentation of quantitative morphology of the two fault surfaces on the Luoyunshan piedmont fault, we identified four earthquake events. Two sets of co-seismic displacement of about 3m and 1m on the fault are obtained; 3)The relationship between the fault surface morphology parameters and the time is described as follows:The fractal dimension of the limestone area decreases with the increase of the exposure time, which reflects the gradual smoothing characteristics after exposed. The phenomenon is opposite to the evolution of the geological features of gneiss faults acquired by the predecessors on the Huoshan piedmont fault; 4)Lithology plays an important role in morphology evolution of fault surface and the two opposite evolution trends of the characteristic fractal value on limestone and gneiss show that the weathering mechanism of limestone is different from that of the gneiss.  相似文献   

19.
活断层运动区段的划分问题   总被引:1,自引:0,他引:1       下载免费PDF全文
刘行松  唐汉军 《地震地质》1992,14(2):140-144
断层运动是复杂而多变的,在一条巨大的断裂带上经常以区段为单位活动,每次活动的区段长度、运动量等都不相同,且往往具有一定的迁移规律等。为工程建设和强震的预测,划分活断层运动区段越来越迫切。以一次强震活动序列、跨断层大地测量网的复测、直接鉴定断层新活动、并结合地形地貌和地下水位变化等途径来划分断层运动的区段  相似文献   

20.
吕德徽  向光中 《内陆地震》1994,8(2):159-165
对毛毛山断裂带断层岩进行了宏观及微观的观察和分析,特别是对断层岩中石英颗粒的形貌特征、溶蚀类型及断层岩的组分进行了研究。结果表明该断裂是一条具有多期活动的全新世活动断裂.滑动性质以粘滑为主,断裂的东段较西段更为明显。  相似文献   

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