共查询到19条相似文献，搜索用时 217 毫秒
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构造三角带通常发育于褶皱冲断带中,是油气勘探的重要目标.构造三角带具有多种几何形态和命名,其中,阿尔伯迭型构造三角带具有普遍意义.近年来,国内外对构造三角带的研究工作取得了重要进展.利用物理模拟和数值模拟并结合实际地质情况,许多学者对构造三角带的演化提出了多种运动学模型和成因解释,本文介绍了2个运动学模型和单斜推进模式.影响构造三角带形成与发展的因素包括滑脱层、地层能干性差异、同构造沉积、剥蚀等.由于其内部构造的复杂性.三角带的地震剖面品质一般较差.而利用地震模拟和生长地层的方法可以在地震剖面上帮助识别出构造三角带.国内的地震勘探表明.中国西部挤压盆地中广泛发育三角带构造.文中列举了中国西部盆地中发育的构造三角带的实例. 相似文献
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陈家断层位于渤海湾盆地辽河盆地西部凹陷中部,是西部凹陷的控制断层台安一大洼断裂的一条分支断层。由于地表、地下构造变形的复杂性及可靠的地震反射资料相对较少,无法判断其深部勘探潜力。在分析区域地质背景基础上,结合高分辨率三维地震及测井、钻井等资料,从地震剖面、生长地层等该断层的几何特征进行剖析,运用平衡剖面技术方法验证了该断层的运动学特征。研究结果表明陈家断层为两期叠加的反转构造,经历了E2s3下-E2s3中期挤压,E2s3中-E2s1＋2期拉张,E2s1＋2～N1g期挤压的过程,产生的断层封堵使得下盘成为有利的油气勘探区。 相似文献
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曾母盆地西部岩石圈特性与有效弹性厚度: 来自构造模拟的约束 总被引：3，自引：1，他引：2
曾母盆地是南海南部最大的新生代沉积盆地,保留了南海新生代共轭边缘演化历史以及性质的重要信息。岩石圈有效弹性厚度Te是了解大陆地壳张裂时岩石圈强度的一个关键指标。本文选取曾母盆地西部的三条典型地震剖面,在构造解释的基础上,按照挠曲均衡原理,通过对三条剖面的反演模拟,对Te进行了敏感性测试。在此基础上利用弹性梁模型对三条剖面进行了正演模拟,来模拟盆地的形态以及主要地层单元的展布。模拟结果与实测剖面的对比表明,Te值取3～5km较为合理,盆地西部的脆性/韧性地壳转换深度为15km。正演和反演模拟中的拉张因子β具有不同的构造含义,正演模拟拉张因子β代表了脆性上地壳的拉伸程度,反演模拟的拉张因子则表示整个岩石圈的拉张作用,拉张因子同时呈向北增大的趋势。 相似文献
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塔里木盆地西南缘逆冲带由西部近东西方向的喀什逆冲构造带和东部近东西方向柯克亚—和田逆冲构造带以及中间喀什—叶城走滑断层系组成,而北西—南东走向的喀什—叶城走滑断层带及其东侧齐姆根构造则为呈北东方向凸出的弧形构造。齐姆根弧形构造在地表地质和地震剖面均表现为向盆地方向倾斜的单斜形态。而且在塔西南地区,该弧形构造上从白垩系到新近系地层厚度明显大于东西两侧逆冲带同时代地层厚度,表现为异常增厚的特征。为了探讨齐姆根弧形构造特征及地层厚度异常增厚等原因,依据前人的地表地质填图成果,以及塔里木盆地西南缘齐姆根地区及邻区完成的二维地震资料及钻井资料成果,对该区地震剖面资料进行详细的构造解释,提出齐姆根弧形构造单斜之下存在3个隐伏逆冲构造楔形体,即棋盘楔形构造、齐姆根楔形构造和英吉沙楔形构造。地震剖面解释的生长地层指出棋盘楔形构造形成最早,为上新世阿图什组沉积时期;其次发育齐姆根楔形构造,为更新世西域组底部沉积时期;最晚发育英吉沙楔形构造,时间大约在更新世西域组中-上段沉积时期,据此认为齐姆根中深层逆冲构造位移扩展方式为前展式。而且地震剖面解释上也揭示了白垩系到新近系地层厚度异常增厚发育的构造部位及发育... 相似文献
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沉积盆地地层及其结构记录了盆地的构造演化过程,并由其所处的不同历史时期的构造背景所决定。全球油气勘探的不断深入和大量地震剖面的完成为系统认识盆地构造演化提供了大量基础资料。本文在板块构造理论的指导下,收集了全球上百个重要沉积盆地的资料编制了2条洲际纬向超长剖面:(1)北美-北非-中东-中亚-东亚纬向超长剖面;(2)南美-非洲纬向超长剖面。这两条洲际纬向超长剖面能直观地显示出不同类型盆地构造演化阶段及其时空对应关系受控于板块运动。盆地发育的程度(沉降厚度、沉降率、构造间断)及其完整性(规模大小、剖面形态、垂向结构),受控于其所处区域的构造背景。北美和南美大陆不同类型沉积盆地存在有序并列的特征:自西向东均为大洋盆地、海沟、弧前盆地、弧后前陆盆地、克拉通盆地、裂谷盆地和被动陆缘盆地。由于板块边界作用影响,相同板块上不同的盆地群之间具有密切的构造-沉积联系和构造事件响应,北非和非洲中部东西向剖面依次发育被动陆缘(西部)-克拉通(中部)-裂谷(偏东部)的特征。 相似文献
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济阳坳陷新生代褶皱-冲断构造的厘定及其动力学背景分析 总被引：9，自引：3，他引：6
以钻井和三维地震剖面的解释为基础,在济阳坳陷首次发现了在沙四段沉积末期形成的近南北向分布的、由东向西逆冲的褶皱-冲断构造,该构造代表了盆地古近纪充填序列中一次重要的构造反转事件,是济阳运动在该区重要的地质表现;通过界面年龄的确定和区域板块构造运动的分析,认为该期构造事件的发生具有区域性,而且与晚始新世初期印度洋板块和太平洋板块重大的运动学调整过程密切相关;该期构造反转事件的确定对于中国东部新生代盆地形成演化的动力学机制的研究和盆地深层油气勘探有重要的意义. 相似文献
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结合区域地震剖面解析和沙箱模拟实验,探讨分析了乍得Bongor盆地反转构造特征及其形成机制。结果表明：（1）
Bongor盆地中发育三种典型的反转构造类型：挤压反转单斜构造、挤压反转向斜构造和挤压反转背斜构造。该类反转构造
一部分具有反转断层相关褶皱样式,主要沿高角度边界断层和基底地垒边界断面发育,形成演化与断裂活动息息相关,另
一部分呈散花状背斜构造样式,属于地层纵弯上拱褶皱,主要发育于斜坡断阶带之间;（2） 区域剥蚀作用对盆地反转构造
演化具有重要的影响,其对盆地内深部地层反转褶皱发育具有促进作用,为深部构造圈闭形成提供条件,而对浅部地层的
反转褶皱发育则表现出阻碍或破坏作用,不利于浅层构造圈闭的形成。 相似文献
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盆地结构记录了盆地演化特征,盆地群结构和构造特征由其所处的构造背景和板块边界决定。随着油气勘探的不断深入,积累了大量地震剖面,为盆地群剖面特征对比,提供了大量的基础资料。本文从大地构造背景着手,通过筛选地震与地质剖面,大致沿北纬39°绘制了欧亚大陆东西向剖面(在东部北黄海盆地有向南的偏转):西起黑海盆地,东至琉球海沟,剖面长约12000km,横穿18个盆地,涵盖克拉通盆地(塔里木原型盆地等)、裂谷盆地(太原盆地、渤海湾盆地等)、前陆盆地(黑海盆地、南里海盆地等)和弧后盆地(东海盆地)等多种盆地类型。其中,陆壳上的盆地发育在前寒武基底上,演化历史悠久;褶皱基底、洋壳基底和洋陆过渡壳基底上发育的盆地主要发育在中新生代。通过详细对比剖面各段结构和构造演化特征,发现中新生代构造活动决定了欧亚大陆中部盆地群最终格架,盆地多具有多期叠合改造的特征。剖面西段盆地群普遍具有中生代伸展断陷,叠加后期挤压坳陷的特征;剖面东段盆地群具有中生代断陷,叠加后期坳陷的特征。现今构造格架由西到东表现为前陆坳陷到弧后坳陷,鄂尔多斯盆地和沁水盆地是本剖面线结构特征分段的枢纽。 相似文献
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研究克拉通内构造变形对于揭示克拉通的构造属性具有重要意义,对于油气勘探也具有重要的参考价值。本文应用钻井与高精度反射地震资料,剖析了鄂尔多斯盆地东南部黄龙背斜的构造几何学与运动学特征。研究表明,黄龙背斜发育在渭北隆起东端,是一长18 km、宽15 km的短轴状背斜,地层起伏幅度达200 ms;黄龙背斜自长城系往上至三叠系均具有相似的背斜形态;它是在燕山期基底断层复活而形成的断层传播褶皱背斜;黄龙背斜区内东西向与南北向剖面控制的缩短分别为70 m和90 m,缩短量较小,指示该部位处于燕山期冲断变形的前锋部位,变形即将终止。黄龙背斜响应于周缘构造边界挤压作用,是克拉通内部的基底正断层反转而在沉积盖层形成的褶皱背斜,因地层能干性差异发生了分层剪切。黄龙背斜是一个有利的天然气勘探目标。 相似文献
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Triangle zones,generally found in foreland fold-and-thrust belts,serve as favorable objects of petroleum exploration.Taking the Dabashan foreland belt as an example,we studied the formation and development of triangle zones,and investigated the effect of decollements and the mechanical contrast of lithology by employing the method of physical modeling.Four experimental models were conducted in the work.The results showed that ’sand wedges’ grew episodically,recorded by deformational length,height and slope angle.The height versus shortening rate presented an S-shape curve,and uplifting occurred successively in the direction of the foreland belt.During the formation of the triangle zone,layer-parallel shortening took place at the outset;deformation decoupling then occurred between the upper and lower brittle layers,divided by a middle-embedded silicone polymers layer.The upper brittle layers deformed mainly by folding,while the lower sand layers by thrusting. As shortening continued,the geometry of a triangle zone was altered.We consider that the triangle zone in the Dabashan foreland belt was modified from an early one based on available seismic profiles and the experimental results.In addition,decollements and mechanical contrast impose significant influence on structural development,which can directly give rise to structural discrepancies.More decollements and obvious mechanical contrast between brittle layers can promote the coupling between the upper and lower brittle layers.Basal decollement controls the whole deformation and decreases the slope angle of the wedge,while roof decollement determines whether a triangle zone can be formed. 相似文献
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沉积盆地构造热演化模拟的研究进展 总被引：18，自引：1，他引：18
沉积盆地构造热演化模拟建立在盆地成因的地质地球物理模型基础之上,其中包括运动学模型、运动学—流变学模型和动力学模型。运动学模型在预测盆地热流演化方面具有优势,但在预测构造沉降等几何形态方面存在一定的缺陷;运动学—流变学模型的优势在于构造演化模拟,在热演化方面类似于运动学模型;动力学模型蕴含着潜在的巨大优势,只是目前还存在一些阻碍因素。构造热演化正演模型的进一步完善及正、反演模型的匹配将是未来构造热演化模拟的发展趋势。 相似文献
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I. El-Hussain Y. Al-Shijbi A. Deif A. M. E. Mohamed M. Ezzelarab 《Arabian Journal of Geosciences》2018,11(15):435
A seismic source model is developed for the entire Arabian Plate, which has been affected by a number of earthquakes in the past and in recent times. Delineation and characterization of the sources responsible for these seismic activities are crucial inputs for any seismic hazard study. Available earthquake data and installation of local seismic networks in most of the Arabian Plate countries made it feasible to delineate the seismic sources that have a hazardous potential on the region. Boundaries of the seismic zones are essentially identified based upon the seismicity, available data on active faults and their potential to generate effective earthquakes, prevailing focal mechanism, available geophysical maps, and the volcanic activity in the Arabian Shield. Variations in the characteristics given by the above datasets provide the bases for delineating individual seismic zones. The present model consists of 57 seismic zones extending along the Makran Subduction Zone, Zagros Fold-Thrust Belt, Eastern Anatolian Fault, Aqaba-Dead Sea Fault, Red Sea, Gulf of Aden, Owen Fracture Zone, Arabian Intraplate, and a background seismic zone, which models the floating seismicity that is unrelated to any of the distinctly identified seismic zones. The features of the newly developed model make the seismic hazard results likely be more realistic. 相似文献
14.
Preparing a seismic hazard model for Switzerland: the view from PEGASOS Expert Group 3 (EG1c) 总被引：1，自引：0，他引：1
The seismic hazard model used in the PEGASOS project for assessing earth-quake hazard at four NPP sites was a composite of four sub-models, each produced by a team of three experts. In this paper, one of these models is described in detail by the authors. A criticism sometimes levelled at probabilistic seismic hazard studies is that the process by which seismic source zones are arrived at is obscure, subjective and inconsistent. Here, we attempt to recount the stages by which the model evolved, and the decisions made along the way. In particular, a macro-to-micro approach was used, in which three main stages can be described. The first was the characterisation of the overall kinematic model, the “big picture” of regional seismogenesis. Secondly, this was refined to a more detailed seismotectonic model. Lastly, this was used as the basis of individual sources, for which parameters can be assessed. Some basic questions had also to be answered about aspects of the approach to modelling to be used: for instance, is spatial smoothing an appropriate tool to apply? Should individual fault sources be modelled in an intraplate environment? Also, the extent to which alternative modelling decisions should be expressed in a logic tree structure has to be considered. 相似文献
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Quantification of seismic activity is one of the most challenging problems faced by earthquake engineers in probabilistic seismic hazard analysis. Currently, this problem has been attempted using empirical approaches which are based on the regional earthquake recurrence relations from the available earthquake catalogue. However, at a specified site of engineering interest, these empirical models are associated with large number of uncertainties due to lack of sufficient data. Due to these uncertainties, engineers need to develop mechanistic models to quantify seismic activity. A wide range of techniques for modeling continental plates provides useful insights on the mechanics of plates and their seismic activity. Among the different continental plates, the Indian plate experiences diffused seismicity. In India, although Himalaya is regarded as a plate boundary and active region, the seismicity database indicates that there are other regions in the Indian shield reporting sporadic seismic activity. It is expected that mechanistic models of Indian plate, based on finite element method, simulate stress fields that quantify the seismic potential of active regions in India. This article explores the development of a finite element model for Indian plate by observing the simulated stress field for various boundary conditions, geological and rheological conditions. The study observes that the magnitude and direction of stresses in the plate is sensitive to these conditions. The numerical analysis of the models shows that the simulated stress field represents the active seismic zones in India. 相似文献
16.
Based on mathematical modeling, the paper presents the estimation of the length of dilatancy zones developed near a free surface
during the preparation of earthquakes. An algorithm for the calculation of dilatancy zones has been developed and applied
for numerical modeling. Estimated examples of the development of near-surface dilatancy zones before the Kamchatka earthquakes
with a magnitude M = 6.7–7.8 are given. The results of the numerical experiments under the accepted assumptions solve the problem of the long-range
influence of a future earthquake source on a limited remote zone of microseismic information gathering: the model admits the
development of near-surface dilatancy zones in the vicinity of a station recording seismic noise that can trigger forerunner
anomalies. 相似文献
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The Finite Element Method (FEM) is widely used in the simulation of geotechnical applications. Owing to the limitations of FEM to model problems involving large deformations, many efforts have been made to develop methods free of mesh entanglement. One of these methods is the Material Point Method (MPM) which models the material as Lagrangian particles capable of moving through a background computational mesh in Eulerian manner. Although MPM represents the continuum by material points, solution is performed on the computational mesh. Thus, imposing boundary conditions is not aligned with the material representation. In this paper, a non-zero kinematic condition is introduced where an additional set of particles is incorporated to track the moving boundary. This approach is then applied to simulate the seismic motion resulting in failure of slopes. To validate this simulation procedure, two geotechnical applications are modelled using MPM. The first is to reproduce a shaking table experiment where the results of another numerical method are available. After validating the present numerical scheme for relatively large deformation problem, it is applied to simulate progression of a large-scale landslide during the Chi-Chi earthquake of Taiwan in which excessive material deformation and transportation is taking place. 相似文献
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Havar Gjoystda Astound Drottning Isabelle Lecomte Mike Branston 《地学前缘》2008,15(1):123-132
根据三维地震地质模型对地震数据进行模拟是从勘探到生产的周期内决策过程中的一个不可或缺的组成部分。虽然对于在储层内的动力过程和地震地质的模型表述已经取得很大进展,但如何从这些模型得到地震数据的精确模拟仍面临很多挑战。通常是在地球模型范围内根据物性用一维褶积方法来模拟地震数据。然而这个过程一般不考虑地震勘探布局和盖层对地震信号的影响。我们审视了为什么这些因素会制约三维地球模型的有效性,并考虑了为什么需要把盖层和地震勘探布局对三维覆盖和分辨率的影响加进模拟过程之中。我们提出了一种新方法,把建立物性模型和一种新的地震模拟技术结合起来,给出一个工作流程;利用这个流程,勘探工作者可以很快模拟出三维的PSDM数据,这些数据加进了盖层和地震勘探布局对覆盖及分辨率的影响。我们利用从远离挪威海岸的一个油田得到的数据,在考虑覆盖和分辨率效应的地震数据模拟之前,对岩石物性做了一些扰动,然后进行地震数据模拟,以此来说明如何可以用这种方法提高三维地球模型的精确性和增进我们对储层的了解。 相似文献