共查询到20条相似文献，搜索用时 31 毫秒
1.
Jun-Mo Kim 《Mathematical Geology》2005,37(8):929-941
On the basis of vectorial formulation, a series of relatively simple closed-form mathematical equations is presented to determine
the direction cosines of the local coordinate axes associated with planar and linear structures in an anisotropic geologic
material from their geologic angle measurements (i.e., strike and dip for planar structures and trend and plunge for linear
structures). The equations are then applied to calculation of global anisotropic hydraulic conductivity and elastic stiffness
tensors with respect to the geographical coordinate axes from their local counterparts with respect to the material symmetry
axes. 相似文献
2.
随着传感器技术的发展,重力场与重力张量场测量技术发展迅速,为实现地下密度分布精细反演提供了数据保障。正演是反演的基础,解决任意密度分布复杂地质体重力场与重力张量正演高效、高精度计算问题,是实现重力高效、精细反演、人机交互反演解释的关键。针对起伏地形和任意密度分布这种复杂条件下二维重力场及重力张量场高效高精度正演问题,这里提出了一种空间波数混合域正演算法,其关键环节包括:①结合新的矩形二度体组合模型波数域表达式和一维Gauss-FFT算法,提出了一种任意密度分布和起伏地形下重力场及重力张量高效、高精度正演算法;②采用新的二维正演算法,计算观测最高点和最低点之间多个不同高度水平网格重力场及重力张量,结合三次样条插值方法,实现了起伏地形上重力场及重力张量场高效、高精度正演。模型算例结果表明,新方法具有高效、高精度的显著特点。 相似文献
3.
Frode Georgsen Per R?e Anne Randi Syversveen Oddvar Lia 《Computational Geosciences》2012,16(2):247-259
In history matching and sensitivity analysis, flexibility in the structural modelling is of great importance. The ability
to easily generate multiple realizations of the model will have impact both on the updating workflow in history matching and
uncertainty studies based on Monte Carlo simulations. The main contribution to fault modelling by the work presented in this
paper is a new algorithm for calculating a 3D displacement field applicable to a wide range of faults due to a flexible representation.
This gives the possibility to apply this field to change the displacement and thereby moving horizons and fault lines. The
fault is modelled by a parametric format where the fault has a reference plane defined by a centre point, dip and strike angles.
The fault itself is represented as a surface defined by a function z = f(x,y), where x, y and z are coordinates local to the reference plane, with the z-axis being normal to the plane. The displacement associated with the fault outside the fault surface is described by a 3D
vector field. The displacement on the fault surface can be found by identifying the intersection lines between horizons and
the fault surface (fault lines), and using kriging techniques to fill in values at all points on the surface. Away from the
fault surface the displacement field is defined by a monotonic decreasing function which ensures zero displacement at a specified
distance from the fault. An algorithm is developed where the displacement can be increased or decreased according to user-defined
parameters. This means that the whole displacement field is changed and points on horizons around the fault can be moved accordingly
by applying the modified displacement field on them. The interaction between several faults influencing the same points is
taken care of by truncation rules and the ordering of the faults. The method is demonstrated on a realistic synthetic case
based on a real reservoir. 相似文献
4.
A novel mathematical framework for modeling folds in structural geology is presented. All the main fold classes from the classical
literature: parallel folds, similar folds, and other fold types with convergent and divergent dip isogons are modeled in 3D
space by linear and non-linear first-order partial differential equations. The equations are derived from a static Hamilton–Jacobi
equation in the context of isotropic and anisotropic front propagation. The proposed Hamilton–Jacobi framework represents
folded geological volumes in an Eulerian context as a time of arrival field relative to a reference layer. Metric properties
such as distances, gradients (dip and strike), curvature, and their spatial variations can then be easily derived and represented
as three-dimensional continua covering the whole geological volume. The model also serves as a basis for distributing properties
in folded geological volumes. 相似文献
5.
用地层倾角测井资料解释复杂构造的方法 总被引：1，自引：0，他引：1
倾角测井矢量图可以标示出井眼范围内各深度点的地层产状，一定的地层构造形态在矢量图上有一定的倾角矢量组合模式。通过正演计算，总结出了１９种褶曲和断层等构造组合模式的样板及在一口井内各构造模式间的“串”、“缺”、“嵌”连接规律。对照组合模式样板进行矢量组合模式识别，采用“倾角矢量逐点叠加法”，可把井眼范围纵向排列的倾角矢量转换成任意方位的地层视产状，绘制构造剖面图。用多个剖面的地层空间坐标数据可绘制倾角构造平面图，确定钻遇构造的形态。据此原理，编制了一套倾角测井构造解释软件系统。 相似文献
6.
斜向逆冲作用在自然界普遍存在,研究斜向逆冲断层相关褶皱的构造几何学特征,识别断层相关褶皱是否存在斜向逆冲有重要意义。文章采用Trishear 4.5、Gocad以及Trishear3D软件构建一系列不同滑移量的断层转折褶皱和断层传播褶皱的二维正演剖面,通过连接一系列不同排列方式的二维剖面建立了三种不同逆冲滑移方向的断层转折褶皱和断层传播褶皱的假三维模型,通过不同假三维模型的比较分析来探讨斜向逆冲断层相关褶皱的构造几何学特征。研究发现,斜向逆冲断层相关褶皱区别于正向逆冲断层相关褶皱的特征主要有两点：① 正向逆冲断层相关褶皱层面等高线图上的最高点与后翼等高线中点的连线以及水平切面上的核心点与后翼中点的连线方向均与断层走向垂直,而斜向逆冲断层相关褶皱的最高点以及核心点与后翼中点的连线方向均与断层走向斜交,并且最高点与后翼等高线中点的连线方向或者核心点与后翼中点的连线方向均与逆冲滑移方向一致;② 在褶皱平行断层走向纵剖面上,正向逆冲断层相关褶皱各个层面最高点的连线是直立的,而斜向逆冲断层相关褶皱各个层面最高点的连线发生倾斜。通过这两个特征可以判别褶皱是否存在斜向逆冲以及逆冲的方向。将模型分析结果运用到四川盆地西南部三维地震勘探资料所覆盖的邛西背斜和大兴西背斜的实例中。研究结果表明,两个背斜均存在右旋斜向逆冲,逆冲方向与各自断层走向的夹角均为70°左右,邛西背斜和大兴西背斜的逆冲方向分别是NE79°和NE77°左右,这与龙门山南段晚上新世以来的主应力方向以及反演的汶川地震最大主应力方向一致。 相似文献
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8.
Hydraulic and mechanical properties of rock masses are largely dependent upon the distribution and variation of fracture areas. Consequently, it is essential to develop good models for analysing the spatial geometric characteristics of fracture fields. The latter, however, may be ascertained only by measuring open cuts or boreholes. The most important factor from the analysis of areas is to be able to determine spatial networks. Without an exhaustive and expensive inventory, the classical methods involving measurements of dip and strike do not provide either a correct estimation of fracture orientations in space, or a good estimation of their distribution. At present, automatic analysis of linear traces on large plane areas is used by several authors1,2 and the field strike and dip measurements are applied only for verification purposes. This method of computing spatial networks is especially suitable because of the nature of data so obtained, since it permits various simulations on computed networks. It is based upon classical methods of vector geometry that involve a measurements data matrix and provide a means of solving a double system of equations. Results are the directional spatial fracture densities. The object of this paper is to define the geometric parameters of this problem and the computation method, to present an example and, finally, to conclude with critical comments supported by certain proposals for a variety of applications. 相似文献
9.
基于三维模型的矿床地质统计学研究,可以准确反应矿体的空间结构变化和品位的空间变化规律,在矿床评价中具有不可替代的作用。本文在已有的钻探工程数据基础上,借助三维建模软件以地质统计学思维对澳大利亚某矿床铅锌品位的空间分布特征及内在规律进行了揭示,通过对矿体铅锌品位在走向、倾向和厚度三个方向的理论变异函数的拟合,表明矿体呈明显的各向异性,在走向方向变程值较大,连续性较好,倾向方向次之。对矿体块体模型空间赋值,并进行投影分析,结果表明矿体沿走向向东矿化范围和强度均有扩大趋势,且在815800E线以东深部倾向方向铅锌品位逐渐增强,高品位矿化断续出现。因此矿区下一步勘查重点应该在矿体走向东部和815800E线以东的倾向延伸方向。 相似文献
10.
通过综合3D地震数据及钻井资料,以三级层序为时间单元制作了不同时期断层位移曲线和断面倾角分布图,对西南庄断层分段的断面几何学与东营组时期运动学特征进行分析。结果表明西南庄断层分段控制了其上盘褶皱几何形态。其中,向斜(半地堑)位于断层位移极大段,背斜位于断层位移极小处即断层段连接处;断层分段的几何学与运动学特征具有明显对应关系,在位移极大段,断层面较陡,而断层段连接处,断层位移较小,对应的断层倾角也较小。边界断层分段活动控制了盆地内可容纳空间、物源供应和古地貌。在断层段中央附近断层活动速率最大,物源供应速率最低,可容纳空间一直是增长的,层序内部准层序以退积和加积式叠置方式为主。而断层段连接处,断层活动速率最小,物源供应速率最高,可容纳空间以下降为主,层序内部准层序以进积式叠置方式为主。因此,沿边界断层走向断层活动性差异控制了层序内部构成样式,是控制断陷盆地陡坡带储层和烃源岩发育的主要因素。 相似文献
11.
A numerical representation that explicitly represents the generalized three-dimensional anisotropy of folded fractured-sedimentary rocks in a groundwater model best reproduces the salient features of the flow system in the Shenandoah Valley, USA. This conclusion results from a comparison of four alternative representations of anisotropy in which the hydraulic-conductivity tensor represents the bedrock structure as (model A) anisotropic with variable strikes and dips, (model B) horizontally anisotropic with a uniform strike, (model C) horizontally anisotropic with variable strikes, and (model D) isotropic. Simulations using the US Geological Survey groundwater flow and transport model SUTRA are based on a representation of hydraulic conductivity that conforms to bedding planes in a three-dimensional structural model of the valley that duplicates the pattern of folded sedimentary rocks. In the most general representation, (model A), the directions of maximum and medium hydraulic conductivity conform to the strike and dip of bedding, respectively, while the minimum hydraulic-conductivity direction is perpendicular to bedding. Model A produced a physically realistic flow system that reflects the underlying bedrock structure, with a flow field that is significantly different from those produced by the other three models. 相似文献
12.
James M. Parks 《Mathematical Geosciences》1974,6(4):353-362
Basin analysis for paleocurrent directions commonly makes use of hundreds of cross-bedding dip and strike measurements taken on structurally tilted sedimentary beds which may be parts of plunging folds. For regional interpretations the desired forms of data are vector means and rose diagrams of dip directions after reduction to the assumed horizontal plane of deposition. Three FORTRAN computer programs have been integrated to perform the data reduction from raw field measurements to graphic plotted rose diagrams. Program PLUNGR rotates the raw field data back to the original horizontal plane of deposition. Output from PLUNGR is a deck of punched cards suitable for input into the second and third programs, with provision for various regroupings of data. VECMEN computes vector mean and other statistics on data groups defined by inserted control cards. Program ROSE, with a variety of options, plots a rose diagram of dip direction azimuths on a CalComp plotter. 相似文献
13.
14.
趋势面分析在东欢坨井田构造研究中的应用 总被引：1，自引：0，他引：1
受区域构造及其演化过程的控制作用,造就了东欢坨矿区构造具有多期次、多性质、多方向、多级别和多序次的特点。选择东欢坨矿大苗庄组8煤层底板标高代表石炭—二叠系含煤地层的起伏变化规律,利用钻孔坐标构建了二维多项式趋势面数学模型。通过对8号煤层底板标高1-4次趋势面和偏差图的分析,提示了开滦矿区东欢坨井田的构造格局:煤层底板有自北东向南西由高到低的变化趋势;主体构造为北东—南西向,趋势图上呈现典型的"反S"型扭曲,且煤层底板等高线趋势面形态显示在走向NE、倾斜ES的单斜基础上,有近东西向构造叠加的格局。该研究还表明煤层底板标高趋势面偏差分析可反映构造形态细节,且随着趋势面偏差次数的增加,分区性更趋明显。 相似文献
15.
估计同震滑移向量对于认识和理解破裂方式和破裂过程具有重要意义。2008年汶川大地震在青藏高原东缘龙门山推覆构造带的中央断裂和前山断裂上各形成了一条长250 km和72 km的地表破裂带。地震发生后至今,已经发表了大量有关同震位错沿破裂带分布的论文和报告,但绝大部分都仅仅是破裂的走向位错和垂直位错,极少有同震滑移向量的报道。这不仅是因为野外难以直接测量到水平缩短量(或拉张量),而且还因为这些走滑位错实际上是视走滑位错,部分或全部来自水平缩短或拉张。因此,仅仅根据视走滑同震位错和垂直同震位错估计的同震总滑移量肯定包含了相当大的误差。尝试利用据不同走向参考线测量到的一组(两个以上)视走滑位错来计算水平滑移向量的这一新方法,获得了中央破裂带上的7个水平同震滑移向量,并结合垂直位错量进一步计算了走滑、倾滑和水平缩短三个同震滑移分量以及断层倾角和破裂面上的同震滑移向量,综合出露破裂面的擦痕所指示的滑移向量,并对比根据矩张量解获得的震源深度的滑移向量,得出以下认识:(1)破裂南段的地表滑移向量的方位角明显小于震源深度滑移向量的方位角,表明在破裂从震源向地表传播过程中破裂面上的滑移向量发生了逆时针旋转;(2)滑移方位角向北东方向逐渐增大,表明地平面上水平滑移向量表现出顺时针旋转的趋势,而且在破裂向北东方向传播过程中近地表的走滑分量逐渐减小而倾滑分量逐渐增大;(3)几乎在每一个观测点倾滑分量都大于走滑分量,表明汶川地震的破裂方式在任何地点都是以逆冲运动为主;(4)破裂面倾角在10.4°～64.7°,平均值为41°,与天然破裂露头和探槽揭示的结果基本一致;(5)滑移向量沿破裂带的分布显示,走滑分量中段大而两端小,倾滑分量则相反,中段小两端大。 相似文献
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17.
AbstractPositive structural inversion involves the uplift of rocks on the hanging-walls of faults, by dip slip or oblique slip movements. Controlling factors include the strike and dip of the earlier normal faults, the type of normal faults — whether they were listric or rotated blocks, the time lapsed since extension and the amount of contraction relative to extension. Steeply dipping faults are difficult to invert by dip slip movements; they form buttresses to displacement on both cover detachments and on deeper level but gently inclined basement faults. The decrease in displacement on the hanging-walls of such steep buttresses leads to the generation of layer parallel shortening, gentle to tight folds — depending on the amount of contractional displacement, back-folds and back-thrust systems, and short-cut thrust geometries — where the contractional fault slices across the footwall of the earlier normal fault to enclose a “floating horse”. However, early steeply dipping normal faults readily form oblique to strike slip inversion structures and often tramline the subsequent shortening into particular directions.Examples are given from the strongly inverted structures of the western Alps and the weakly inverted structures of the Alpine foreland. Extensional faulting developed during the Triassic to Jurassic, during the initial opening of the central Atlantic, while the main phases of inversion date from the end Cretaceous when spreading began in the north Atlantic and there was a change of relative motion between Europe and Africa. During the mid-Tertiary well over 100 km of Alpine shortening took place; Alpine thrusts, often detached along, or close to, the basement-cover interface, stacking the late Jurassic to Cretaceous sediments of the post-extensional subsidence phase. These high level detachments were joined and breached by lower level faults in the basement which, in the external zones of the western Alps, generally reactivated and rotated the earlier east dipping half-graben bounding faults. The external massifs are essentially uplifted half-graben blocks. There was more reactivation and stacking of basement sheets in the eastern part of this external zone, where the faults had been rotated into more gentle dips above a shallower extensional detachment than on the steeper faults to the west.There is no direct relationship between the weaker inversion of the Alpine foreland and the major orogenic contraction of the western Alps; the inversion structures of southern Britain and the Channel were separated from the Alps by a zone of rifting from late Eocene to Miocene which affected the Rhone, Bresse and Rhine regions. Though they relate to the same plate movements which formed the Alps, the weaker inversion structures must have been generated by within plate stresses, or from those emanating from the Atlantic rather than the Tethyan margin. 相似文献
18.
三峡库区作为地质灾害的多发地区,有关构造特征与滑坡之间关系以及相同局部构造上多个个体滑坡之间的因果关
系研究很少。在应用相关理论方法的基础上,结合工程地质研究现状,以谢家包断层传播褶皱为研究重点,对局部构造与滑
坡类型之间的关系进行深入研究,上盘断坡形态特征控制着长江流域和青干河流域滑坡群分布,使其在整体空间演化上表
现出从西向东滑坡体规模逐渐减小的变化规律;长江流域滑坡群规模明显大于青干河流域滑坡群,这与断层传播褶皱两翼
倾角变化密切相关,南翼青干河流域岩层倾角明显大于北翼长江流域岩层倾角。研究表明大型滑坡发生与局部构造类型及
河流切割局部构造的部位相关,这种相关性不仅体现在对单个滑坡的控制,还在于对整体岸坡带演化规律、个体滑坡演化
之间因果关系的控制上。 相似文献
19.
Masashige Hirano 《Mathematical Geology》1993,25(7):795-818
The ages of layered strata show a particular spatial distribution, and the bedding plane is isopotential surface of a scalar T(x, y, z) correlative to the age of a given stratigraphic horizon. The scalar T is obtained as the solution of boundary value problem of Laplace equation in power series, and the solution describes the three-dimensional geologic structures within an analytical space bounded by faults or unconformities on which the value of T jumps. The solution is termed the horizon function and consists of the datum succession and the structural part. The datum succession defines the relationship between the relative age (time-scale; T) and the thickness of strata (spatial scale; z) for undeformed horizontal strata. Geologic structures are described by the structural part of the solution composed by Fourier series, and the coefficients included there are determined by the least-square method using the dip and strike defined by particular combinations of the derivatives of T or the horizon data obtained in the area. The undersampled nature of geologic data is overcome by the selection of solution type, Eigenvalues, and boundary condition. Geological map and cross-sections are composed quantitatively and automatically by combining the spatial distribution of investigated T with the digital map defining the landform of the area. Test results were examined from this point of view. Improvement of the structural part to have the result fit completely the measured data is possible by introduction of the multiplying polynomials, although this concerns mathematical nature of the potential T. 相似文献
20.
Stig A. Schack Pedersen 《Journal of Structural Geology》1981,3(3):253-264
The development of computer support in photogrammetric measurements has facilitated quick calculations of structural geological elements such as strike and dip, fold axes and axial planes. Computer-assisted photogrammetric methods have been applied in a structural analysis of 3000 km2 in central Peary Land, North Greenland. Detailed studies have been carried out in an area covered by a single stereo model representing part of the southernmost margin of the North Greenland Fold Belt. On the basis of the aerial photos, a map with both lithological boundaries and structural measurements may be drawn. In little known areas with complex structural relationships field work is necessary to control the interpretation. In the present study refolded thrust fault structures were investigated. Preparatory photogrammetric studies allow the limited time available for field work to be effectively utilised, and accurate geological maps to be produced relatively quickly. 相似文献