共查询到20条相似文献，搜索用时 31 毫秒
1.
库车坳陷中段克拉苏构造带广泛发育盐相关收缩构造变形,总体具有"垂向叠置、分层变形"的整体挤压变形特征。沿东-西向克拉苏构造带不同区段深浅层构造变形样式、断层位移存在明显差异,北部盐下层由1～2条高角度基底卷入逆冲断层为主导,并在断层下盘发育捷径断层。区域结构平衡剖面和先存构造活动趋势分析结果表明,克拉苏构造带北侧变形属于基底卷入变形,早期先存断裂在后期收缩变形中重新活动,形成高角度的逆冲断裂。物理和数值砂箱模拟结果表明,盐岩层先于其上、下地层发生变形,其厚度、分布及边界条件差异是造成垂向分层收缩变形的主要控制因素。 相似文献
2.
The basic assumption of quantitative structural geology is the preservation of material during deformation. However the hypothesis of volume conservation alone does not help to predict past or future geometries and so this assumption is usually translated into bed length in 2D (or area in 3D) and thickness conservation. When subsurface data are missing, geologists may extrapolate surface data to depth using the kink-band approach. These extrapolations, preserving both thicknesses and dips, lead to geometries which are restorable but often erroneous, due to both disharmonic deformation and internal deformation of layers. First, the Bolivian Sub-Andean Zone case is presented to highlight the evolution of the concepts on which balancing is based, and the important role played by a decoupling level in enhancing disharmony. Second, analogue models are analyzed to test the validity of the balancing techniques. Chamberlin's excess area approach is shown to be on average valid. However, neither the length nor the thicknesses are preserved. We propose that in real cases, the length preservation hypothesis during shortening could also be a wrong assumption. If the data are good enough to image the decollement level, the Chamberlin excess area method could be used to compute the bed length changes. 相似文献
3.
文章将三种以面积平衡为原理的几何学方法应用在物理模拟拉张实验中，对比三种方法的结果与模型设计参数间的
误差，讨论了三种方法的优缺点和适用范围。其中层长守恒方法需要假设在构造变形过程中层长保持不变，通过曲线拉直
可以恢复构造各阶段拉张量和拉张总量。利用面积守恒可以计算拉张构造中滑脱层深度，面积深度法允许构造变形过程中
层长和层厚的变化，多个构造前沉积地层的面积深度拟合直线可以反映构造整体拉张量和滑脱层深度。面积守恒法在已知
构造滑脱层位置的基础上，通过同构造沉积地层可以计算出拉张活动不同阶段拉张量变化和拉张总量。结合琼东南长昌凹
陷剖面特征，面积守恒法是计算其拉张量变化最准确又有效的方法，面积守恒法应用结果确定过长昌凹陷剖面在岭头组、
崖城组和陵水组沉积阶段的拉张量分别为13.8 km、15 km和21.4 km，拉张总量为50.2 km，拉张率为42.7%。三种方法在物
理模拟实验和琼东南盆地中的应用结果表明，在伸张构造中由于剪切变形作用，基于面积守恒的方法优于层长守恒的方
法。面积深度法利用构造前沉积地层的几何形态来预测构造整体拉张量和滑脱层深度，面积守恒法可以利用同构造沉积地
层和已知的滑脱层位置来预测拉张构造整体的拉张量和不同阶段的拉张量变化。 相似文献
4.
文章将三种以面积平衡为原理的几何学方法应用在物理模拟拉张实验中,对比三种方法的结果与模型设计参数间的
误差,讨论了三种方法的优缺点和适用范围。其中层长守恒方法需要假设在构造变形过程中层长保持不变,通过曲线拉直
可以恢复构造各阶段拉张量和拉张总量。利用面积守恒可以计算拉张构造中滑脱层深度,面积深度法允许构造变形过程中
层长和层厚的变化,多个构造前沉积地层的面积深度拟合直线可以反映构造整体拉张量和滑脱层深度。面积守恒法在已知
构造滑脱层位置的基础上,通过同构造沉积地层可以计算出拉张活动不同阶段拉张量变化和拉张总量。结合琼东南长昌凹
陷剖面特征,面积守恒法是计算其拉张量变化最准确又有效的方法,面积守恒法应用结果确定过长昌凹陷剖面在岭头组、
崖城组和陵水组沉积阶段的拉张量分别为13.8 km、15 km和21.4 km,拉张总量为50.2 km,拉张率为42.7%。三种方法在物
理模拟实验和琼东南盆地中的应用结果表明,在伸张构造中由于剪切变形作用,基于面积守恒的方法优于层长守恒的方
法。面积深度法利用构造前沉积地层的几何形态来预测构造整体拉张量和滑脱层深度,面积守恒法可以利用同构造沉积地
层和已知的滑脱层位置来预测拉张构造整体的拉张量和不同阶段的拉张量变化。 相似文献
5.
The displacement-distance (d−x) method can be modified to study the geometry and development of contractional kink bands by dividing displacements into cartesian component vectors. Kink bands are idealised as having constant layer lengths, enabling simple trigonometry to be used to determine the displacement of one wall of the kink band relative to the other wall.
In a consideration of several applications of the d−x method for kink bands, it is shown that displacement is transferred between conjugate and overstepping kink bands in a similar way to displacement transfer between conjugate and overstepping faults and extension fractures. The several different models of kink band formation are shown to each have different displacement characteristics. The d−x method can also be used to study the geometry and evolution of folds related to thrust-propagation and ramps, which are often modelled as having kink band geometries. For instance, the d−x method can be used to show how fault-tip and fault-bend folds cause or accommodate thrust displacement variations, and to estimate displacement rates from the amounts of deformation in different syn-thrust sedimentary layers. 相似文献
6.
通过分析法向应力、干密度、土样尺寸对吹填粉砂土蠕变特性的影响,深入研究其固结蠕变特性。与Kelvin模型相比,采用Burgers体模型能够更合理地阐释吹填粉砂土的蠕变曲线;采用FLAC3D方法可开展吹填土蠕变过程的三维数值模拟。结果表明：吹填粉砂具有一定的蠕变特性,并可用幂函数描述应力-应变、应变-时间的关系;干密度一定时,法向应力愈大,初始应变愈大,达到稳定的时间愈长;法向应力一定时,干密度越大,初始变形越小,最终稳定所需时间越短;大尺寸试样（Ф 200.0 mm× H200.0 mm）的瞬时变形与蠕变形率要比标准尺寸（Φ 61.8 mm×H 20.0 mm）大,稳定所需时间要长;此外,Burgers体模型模拟吹填粉砂土固结蠕变变形优于广义Kelvin模型并具有可行性。 相似文献
7.
To check the behaviour of physical experiments of simple rollover anticlines over listric normal faults, several fault-slip, bed-length and area parameters are measured for different beds in two stages of evolution of two physical experiments. Given a certain amount of extension, the heave and dip of the displacement vary for different beds, whereas the throw is approximately constant for small amounts of extension and the displacement remains constant for high amounts of extension. Neither bed lengths nor areas beneath beds remain constant with increasing extension. A number of techniques allow amounts of extension and detachment depth to be estimated given one or more marker horizons, the portion of the fault between hanging-wall and footwall cut off points, the depth to detachment and/or the shear angle. These techniques are applied to the physical experiments of listric normal faults analysed. Since many of these techniques rely on parameters measured on the physical experiments such as fault slip, bed length and area, the influence of these parameters on the different magnitudes of extension and detachment depths estimated using different techniques is discussed and the accuracy of the results is compared. 相似文献
8.
The Tulungwan-Chaochou Fault system in southern Taiwan represents the boundary between a slate belt of moderate metamorphic grade and a relatively unmetamorphosed fold-and-thrust belt. The offset between hanging wall and footwall of this fault ranges from 7 to 11 km and is considered one of the major tectonostratigraphic faults in Taiwan. This 75-km-long fault system is also one of the most conspicuous topographic features in Taiwan. The geometry, kinematic history and associated subsidiary structures have not been resolved. Field mapping of fabrics and brittle faults show that a 45-km-long west-northwest-vergent antiform defined by folded slaty cleavage exists in the hanging wall of the fault. This antiform has not been previously described and apparently formed in a brittle environment. The flat crest and tight forelimb of the antiform suggests a two-stage deformation model composed of a fault-bend fold followed by a trishear fold. We infer that regional scale fold is associated with a thrust that splays upward from the main detachment. 相似文献
9.
饱和层状砂土液化特性的动三轴试验研究 总被引：2，自引：0，他引：2
利用GDS动三轴试验系统采用等幅循环应变加载方式对含有不同厚度粉土的饱和层状砂土进行了液化强度试验。分析了均匀砂和含有不同粉粒层厚度的层状砂土在循环荷载作用下的变形和力学特性。试验分析表明：由于含粉粒夹层的层状土特殊的土体结构,其孔隙水压力发展规律与一般的无黏性砂土不同;饱和层状砂土的抗液化强度并不是随着粉粒层厚度的增加而单调增加的,而是存在一个临界点;液化临界剪应变的大小与液化判别标准和循环次数有很大关系。试验结果表明,粉粒夹层对层状砂土的液化特性有很大的影响,且更能模拟自然环境条件下的层状砂土地基液化特性。 相似文献
10.
古地貌是控制古水系、沉积体系的关键因素之一.以渤海湾盆地渤中坳陷东部的辽东东地区中新世馆陶组为例,对馆陶组的沉积区和剥蚀区分别开展了基于残余地层厚度法和印模法的古地貌恢复,以增进对研究区古水系、源－汇系统的整体认识,为其物源体系、沉积环境、砂体分布的预测提供科学依据.两种方法的古地貌及古水系恢复结果对比研究表明,基于残余地层厚度法的沉积区古地貌恢复结果适用于目的层沉积区古水系的恢复;而基于印模法的沉积区－剥蚀区一体化的古地貌恢复结果实现了剥蚀区、沉积区古水系的统一解释.沉积区－剥蚀区一体化的古地貌恢复弥补了基于沉积区古地貌的古水系恢复中难以判断"源－汇体系"中源区古水系分布及从源到汇古水系派生关系的局限性. 相似文献
11.
玛东褶皱-冲断带是世界上保存最好的早古生代褶皱冲断带之一,也是塔里木油气勘探的重点区域之一。褶皱-冲
断带浅部构造由于遭受强烈剥蚀,为玛东褶皱-冲断带的构造样式和变形机制研究带来巨大的挑战。断层相关褶皱理论定
量化建立了断层形态和褶皱形态几何学和运动学的关系,是一种有效的利用断层形态来推测褶皱形态的方法,为恢复玛东
地区被剥蚀区域的构造形态提供了可能。文中详细介绍了断层转折褶皱和断层传播褶皱的几何学和运动学特征,并将其应
用于玛东地区的典型构造中,建立2 种玛东地区构造变形模式。最后结合工业地震剖面和钻井资料,认为玛东地区的主要
构造样式是断层转折褶皱, 并分析了构造样式对油气圈闭的影响。 相似文献
12.
通过试验资料,说明了应力路径对砂土的应力-应变关系的影响;从实测资料及有限元法计算的结果,分析了土石坝中应力路径的特点;然后介绍了部分现有在土石坝变形计算中考虑应力路径影响的方法;最后,通过砂土的等应力比及变应力比路径试验资料的分析,揭示了二者之间具有良好的相关关系,推导了变应力比路径下非线性弹性模型参数的计算方法,提出了在土石坝变形计算中考虑应力路径影响的分析方法。 相似文献
13.
围绕库车前陆盆地内某典型断层转折褶皱剖面,实测统计该剖面不同构造部位的剪切裂缝,分析断层转折褶皱中剪切裂缝的发育规律,进而建立断层转折褶皱剪切裂缝的发育模式。统计结果表明,研究区剪切裂缝有2种类型,一类是与岩层面高角度相交的高角度缝,广泛发育在构造各个部位;另一类是与层面近于平行的顺层裂缝,主要发育在断层面附近,并随岩层的变形,产状发生改变。远离断层面,剪切裂缝发育程度整体上呈减小趋势,下盘裂缝发育强度的减小大于上盘,上盘裂缝发育强度整体大于下盘。褶皱内层剪切裂缝较外层发育,褶皱两翼裂缝发育强度大于褶皱枢纽。断层产状的改变,会引起上盘运动状态的改变,使得在上盘活动轴面附近出现应力集中,局部剪切裂缝发育强度出现增大现象。断层转折褶皱剪切裂缝的发育模式可以分为3个阶段,断层形成前主要发育与层面高角度相交的区域性剪切裂缝;断层形成初期,断层面附近两盘牵引变形不明显,上盘穿过断坡下部破折点处活动轴面的部分会产生新的剪切裂缝,即与岩层高角度相交剪切缝和与断层面低角度相交剪切缝;牵引构造明显时,断层面附近两盘弯曲部位会产生顺层剪切裂缝,两翼的裂缝发育强度大于枢纽。 相似文献
14.
15.
平行式断弯褶皱作用在各造山带的前陆部分,特别是在褶皱逆冲带中是普遍存在的。这些地区的大多数未变质及浅变质的沉积岩系在变形过程中,其厚度未发生重大改变,有利于定量构造研究方法的应用。查明这些地区的基本构造格架,不仅对找寻有用资源具有重要实际意义,而且对造山带内部研究提供了重要线索。本文内容以John suppe的研究为主,重点介绍了平行式断弯褶皱的几何学及运动学特征,以及一系列有关的定量研究方法。这些方法对于检验构造横剖面内部的一致性,建立平衡剖面是非常有用的工具。而且,某些思路并非仅限于平行变形行为的研究。 相似文献
16.
《Journal of Asian Earth Sciences》2011,40(6):627-634
Analysis of surface and subsurface structures, variation of shortening amounts obtained by restoration of deformed cross-sections, and occurrence of younger hangingwall rocks over the older footwall rocks across the Vaikrita Thrust in the Higher Himalaya suggests reactivation of early normal faults as thrusts. Based on this, an inversion tectonics model is proposed for structural development of the Himalaya. The model explains the geometrical shape of the Himalaya as primary arcuation and helps in resolving superimposed deformation in the region. 相似文献
17.
《Journal of Structural Geology》1994,16(4):571-584
The Doublespring duplex, located in the Lost River Range of Idaho, is a Sevier age fault-related fold complex in massive limestones of the Upper Mississippian Scott Peak Formation. Folds within the duplex closely resemble fault-bend fold geometrics, with open interlimb angles and low-angle bed cut-offs. Narrow, widely spaced, bedding-parallel shear zones with well-developed pressure solution cleavage alternate with massive, relatively undeformed layers on fold limbs. Shear zones are developed only on the limbs of anticlines, and have similar but unique morphologies in each of three different folds. Incremental strain histories reconstructed from antitaxial fibrous overgrowths and veins within the shear zones constrain the kinematics of folding. Shear zones experienced distributed bedding-parallel simple shear (flexural flow) towards pins near axial surfaces, while adjacent massive layers experienced rotation through an externally fixed extension direction. The absence of footwall synclines and morphological differences in shear zones from adjacent folds suggest that faulting preceded folding. Kinematic histories of folds that have experienced different translational histories are identical, and are not compatible with strain histories predicted from previous kinematic models of fault-bend folding. Shear zone development and fiber growth is instead interpreted to have occurred during low amplitude fixed-hinge buckling in response to initial resistance to translation of the thrust sheet. Fault-bend folding with mobile axial surfaces occurred with translation of the thrust sheets once the initial resistance to translation was overcome and resulted in no penetrative strain. 相似文献
18.
广义"断层转折褶皱"的几何学正演数值模拟 总被引：2，自引：0，他引：2
提出了一个广义“断层转折褶皱”的几何学数值模拟方法,并用C＋＋语言编制了相应的数值模拟软件。该软件能模拟非常复杂的褶皱冲断系统,包括多转折“剪切断层转折褶皱”（multi-bend shear fault-bend folds）、复合楔体构造（composite wedge structures）、以及多滑脱层褶皱冲断系统（multi-detachment fold and thrust systems）。通过把一个沉积岩层分解成“膝折带”（kink-band）和“膝折楔”（kink-wedge）两部分,解决了模拟曲线形态的多转折断层转折褶皱的难点问题,而以往的几何学方法仅对真实的褶皱形态作了粗略的线性近似。通过把复杂的褶皱冲断系统分解成一系列迭加的滑脱层系,可以模拟复杂的楔体构造,并提供这些构造演化的二维动画。该软件被应用于美国加里福尼亚州的Wheeler山脊,一个活动的楔体构造,其构造解释得自于大量钻井数据,正演数值模拟再现了该构造的主要特征。 相似文献
19.
将计算机数字图像测量技术应用于土工静力三轴试验的土样变形测量,实现了土样变形的非接触测量。针对南宁饱和细砂,采用干装敲击法和控制不同初始成样含水率的湿装夯实法制备松砂和密砂试样,联合采用数字图像测量技术与常规三轴变形量测方法,在不同围压下进行了固结排水剪切试验。着重探讨了成样方法、初始成样含水率、密实程度、固结围压对两种量测方法所获得的应力-应变关系与邓肯-张模型中的切线模量5参数的影响。试验结果表明：成样方法、初始成样含水率、密实程度和围压决定土样的剪切破坏形式,影响应力-应变关系;剪切破坏的形式以及剪切带位置的不同,导致图像测量和常规三轴试验获得的轴向应变和偏应力数值均存在不同程度的差异;邓肯-张模型5参数不仅受到试样的成样方法、初始成样含水率、密实程度的影响,而且受到量测方法的影响。 相似文献
20.
Mohammad Irfan Ahmad A. K. Dubey Giovanni Toscani Lorenzo Bonini Silvio Seno 《International Journal of Earth Sciences》2014,103(1):329-347
Kinematic evolution of fold-thrust structures has been investigated by analogue models that include syntectonic sedimentation. Different decollement dips and basement thicknesses produced different wedge geometries and propagating characteristics. A model with one decollement level was characterized by a closely spaced thrust system during early stages of shortening as compared to the late stages. The frequency of fault nucleation was rapid during the early stages of deformation. Conversely, the frequency of fault nucleation was low and thrust spacing was significantly wider in a model with two decollement levels. Individual faults became locked at steep dips and deformation stepped forward as a new fault nucleated in-sequence in front of the older locked structure. Once the thrust system was established up to 27 % overall shortening, an overlying bed was introduced to simulate syntectonic deformation. Model sand wedge did not grow self similarly but rather its length and height increased episodically with deformation. Restoration of deformed models show that layer parallel shortening accommodated for approximately half of the total model shortening across the multilayers. Calculated error in apparent layer shortening from the restored layers revealed a direct relation with depth of the layers in the models. The experimental results are comparable to a natural example from the Northern Apennines fold-and-thrust belts. 相似文献