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1.
针对地质环境中不同断层构造出现交叉、削截等现象而构成的复杂断层网络,本文基于隐函数曲面重建提出了一种三维断层网络隐式建模方法。该方法首先以径向基隐函数曲面重建理论为基础,基于地质剖面图中断层轮廓线数据以及断层产状信息隐式构建三维断层面模型;然后使用二叉树结构描述不同断层间的空间拓扑关系构建断层网络模型;最后,考虑断层建模中产状信息估计的不确定性,定义了断层面法向量概率分布模型,采用信息熵指标定量评价断层模型质量。以贵州水银洞金矿床为实例矿床,选定包含多条断层的区域作为试验区,采用该方法构建了实例三维断层网络模型,结果表明,基于隐函数曲面的三维断层网络建模方法能快速构建区域内多条断层的三维断层网络模型和拓扑结构,有助于复杂断层网络快速建模和三维形态分析,为断层构造定量研究提供基础。  相似文献   

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基于线框架模型的三维地质断层结构模型及其构建技术   总被引:1,自引:0,他引:1  
基于地质断层构造的特点,文中提出了一种适合三维断层模拟的数据模型——线框架模型,并基于该数据模型详细描述三维断层结构模型的构建方法,实现了从层面结构的地质模型向块体结构的地质模型进行自动转换的关键算法。线框架模型以方向线框架来表达地质模型的骨架,以方向TIN网来表达地质模型的血肉,具备地质断层结构模型所要表达的各种几何元素与拓扑关系。基于线框架模型的三维地质断层构模技术将地质界面之间的交切在地质界面三角网形成之前就进行处理,将面与面之间的切割操作简化为线与线之间的操作,这种方法不仅能有效地减轻断层地质体构模的复杂程度,而且可以将线与线之间的交线作为地质界面三角网构建时的约束边,从而有效地保证了地质界面之间交切关系的正确性。  相似文献   

4.
为实现地质剖面图中复杂断层的自动生成,通过分析断层数据类型,实现断层数据规范化处理;分析断层自身的基本要素(断点、断距、性质、走向、倾向、与地层的切割、错动关系等),提出采用“复原法”构建单一断层模型的方法;依据复杂断层的空间拓扑关系及其重要性,划分断层级别,理顺断层之间、断层与地层之间的关系,探索出地质剖面图中复杂断层的自动生成方法。通过开滦某煤矿的地质数据验证了该方法的有效性。该方法可依据用户需要,生成任意方向的地质剖面数据,为基于剖面的三维建模提供了充足的原始建模数据。   相似文献   

5.
一种面向对象的三维地下空间矢量数据模型   总被引:1,自引:0,他引:1  
针对地下空间的真三维连续特性以及建模过程的动态交互编辑与分析要求,提出了一种新的三维地下空间矢量数据模型。该模型采用面向对象思想对地下各种空间对象进行抽象描述;利用模型中的线段要素增强几何元素之间拓扑连接关系的维持,为地质体的切割和地下工程体的开挖等分析提供了算法上的便利;引入拓扑面更好地表达了地下空间对象之间的拓扑邻接关系。该模型在三维地下空间数据的存储管理、查询分析以及实时逼真绘制等方面都表现出较好的性能,适用于地下勘探工程的建模与分析。  相似文献   

6.
This paper focuses on fault-related uncertainties in the subsurface, which can significantly affect the numerical simulation of physical processes. Our goal is to use dynamic data and process-based simulation to update structural uncertainty in a Bayesian inverse approach. We propose a stochastic fault model where the number and features of faults are made variable. In particular, this model samples uncertainties about connectivity between the faults. The stochastic three dimensional fault model is integrated within a stochastic inversion scheme in order to reduce uncertainties about fault characteristics and fault zone layout, by minimizing the mismatch between observed and simulated data.  相似文献   

7.
This paper describes the properties of faults and fractures in the Upper Cretaceous Chatsworth Formation exposed at Santa Susana Field Laboratory and its surroundings (Simi Hills, California), where groundwater flow and contamination have been studied for over three decades.The complex depositional architecture of this turbidite consisting of alternating sandstones and shales, interacting with formative stress conditions are responsible for multi-scale fault hierarchies and permeable fractures in which nearly all groundwater flow occurs.Intensity and distribution of background fractures and their relation to bedding thickness are established for sandstones, the dominant lithology. The architecture of faults with increasing displacement is described, and relationships among fault dimensional parameters captured.Data from ∼400 boreholes and piezometers reveal the effect of faults and fractures on groundwater flow. Large hydraulic head differences, observed across fault zones with shale-rich cores, indicate these structures as cross-flow barriers. Moreover, hydraulic head profiles under ambient conditions, and pumping tests suggest strong hydraulic connectivity in all directions to depth of hundreds of meters.This outcrop-based structural characterization relates the horizontal hydraulic conductivity to the observed well-connected fracture network, and explains the strong vertical connectivity across low-hydraulic conductivity shales as faults and sheared fractures provide flow pathways.  相似文献   

8.
The widely accepted faulting theory of Anderson fails to explain three more coeval sets of faults or faults developed in a three-dimensional strain field. Reches has developed a model which suggests that four sets of faults, arranged in orthorhombic symmetry about the principal strain axes, are necessary to accommodate general, three-dimensional strain. This paper presents the odd-axis model, which recognizes certain geometric and kinematic relationships inherent in orthorhombic fault systems and in the Reches model and presents a practical method for decoding the strain significance of fault systems developed in three-dimensional strain fields. Both the odd-axis model and the Reches model are applied to an array of orthorhombic faults in the northern San Rafael Swell of central Utah with excellent agreement between predicted and observed geometric and kinematic parameters.  相似文献   

9.
Increased interest in the two- and three-dimensional geometries and development of faults and other types of fractures in rock has led to an increasingly bewildering terminology. Here we give definitions for the geometric, topological, kinematic and mechanical relationships between geological faults and other types of fractures, focussing on how they relate to form networks.  相似文献   

10.
The purpose of this paper is to examine the kinematic behaviour of normal fault systems and see what general conditions govern their geometrical evolution. We pay particular attention to seismological and surface data from regions of present day active normal faulting, as the instantaneous three-dimensional geometry at the time of fault movement is better known in active regions than in areas where the faults are now static.Most normal faults are concave upward, or listric. This shape can be produced by geometric constraints, either because the faults reactivate curved thrusts, or because they must be curved to accommodate rotations. Another effect which will produce curved faults is the variation of rheology with depth: brittle failure at shallow depths produces less fault rotation than does distributed creep in the lower part of the crust. An important geometric feature of normal faulting is the uplift of the footwall. The amount of such uplift is related not only to the elastic properties of the lithosphere, but also to the throw and dip of the fault. A striking feature of active normal faults is that they occur in groups in which all the faults dip in the same direction. This behaviour arises because the faults cannot intersect: if they do, one must cease to be active. The rotation which such fault systems produce reduces the dip of the faults until a new steeply dipping fault is formed. Once a new fault cuts pre-existing faults the earlier faults become locked, and a new set of faults must propagate rapidly across the whole region involved. Many of these geometric constraints also apply to thrust faulting.  相似文献   

11.
塔里木盆地塔北隆起发育两组呈小角度相交(40°)的透入性X型走滑断裂,分别沿着NNE走向和NNW延伸。在对塔北哈拉哈塘地区三维地震资料解释的基础上,对走滑断层的几何展布特征以及断层的剖面变形特征进行研究;同时重点解析了RP6断裂和HA13断裂,分析比较NNW向与NNE向断层的变形及发育特征差异;结合盆地重磁资料以及周缘造山带的活动特征,对塔北隆起小角度的X型走滑断层的发育机制以及演化进行了分析。研究表明,塔北隆起走滑断层在垂向上具有明显的分层变形特征,分为三个构造层:震旦系-中寒武统下构造层(TH3界面以下)、上寒武统-中奥陶统中构造层(TH3-TO3t界面)和上奥陶统-石炭系上构造层(TO3t-TP界面)。断层在下构造层和中构造层中整体处于压扭环境,多发育正花状构造;上构造层中断层主要发育负花状构造或正断层,整体处于张扭环境。两组断裂比较,NNW向断裂活动性强,在各构造层中均有显著的断裂特征发育,垂向连通性强,发育先存基底断裂,而NE向断层主要发育在中构造层,在下构造层和上构造层中断层发育不明显。活动性分析表明,断层的形成与演化具有多期性,走滑断层的形成经历了三期主要活动:中寒武世末、中晚奥陶世和志留纪-石炭纪。塔北隆起X型走滑断裂的形成受到了NNW向基底断裂和薄弱带的控制,NNW向先存基底断裂带或薄弱带优先发育走滑断裂,基底断裂与主挤压应力方向的夹角小于45°-Φ/2,NNE断层的发育受NNW向先存断裂限制,最终形成小角度相交的X型断裂。  相似文献   

12.
3D structural modeling is a major instrument in geosciences, e.g. for the assessment of groundwater and energy resources or nuclear waste underground storage. Fault network modeling is a particularly crucial step during this task, for faults compartmentalize rock units and plays a key role in subsurface flow, whether faults are sealing barriers or drains. Whereas most structural uncertainty modeling techniques only allow for geometrical changes and keep the topology fixed, we propose a new method for creating realistic stochastic fault networks with different topologies. The idea is to combine an implicit representation of geological surfaces which provides new perspectives for handling topological changes with a stochastic binary tree to represent the spatial regions. Each node of the tree is a fault, separating the space in two fault blocks. Changes in this binary tree modify the fault relations and therefore the topology of the model.  相似文献   

13.
This paper reviews the data concerning the fracture network and the hydraulic characteristics of faults in an active zone of the Gulf of Corinth. Pressure gap measured through fault planes shows that in this area the active normal faults (Aigion, Helike) act, at least temporarily and locally, as transversal seal. The analysis of the carbonate cements in the fractures on both the hangingwall and the footwall of the faults also suggests that they have acted as local seals during the whole fault zone evolution. However, the pressure and the characteristics of the water samples measured in the wells indicate that meteoric water circulates from the highest part of the relief to the coast, which means it goes through the fault zones. Field quantitative analysis and core studies from the AIG-10 well have been performed to define both regional and fault-related fracture networks. Then laboratory thin section observations have been done to recognize the different fault rocks characterizing the fault zone components. These two kinds of approach give information on the permeability characteristics of the fault zone. To synthesize the data, a schematic conceptual 3D fluid flow modeling has been performed taking into account fault zone permeability architecture, sedimentation, fluid flow, fault vertical offset and meteoric water influx, as well as compaction water flow. This modeling allows us to fit all the data with a model where the fault segments act as a seal whereas the relays between these segments allow for the regional flow from the Peloponnese topographic highs to the coast.  相似文献   

14.
The main structural characteristics of the Caggiano and Polla faults, exposed in the epicentral area of the 1561 earthquake (Mw = 6.4), southern Italy, have been investigated in detail to assess their spatial and temporal properties, and to evaluate their seismogenic potential. These right stepping normal faults show an overlap of about 7 km and an across strike separation of about 4 km. The geometric relationships between the Caggiano and Polla faults, but also the displacement distribution along each fault, demonstrate that they have been strongly interacting throughout the Pleistocene. Nevertheless, geological evidence of Holocene tectonic activity was mainly recognized along the Caggiano Fault (faulted late glacial deposits) and in the southernmost part of the Polla Fault (faulted deposits of probably Late Pleistocene age). This suggests that the Caggiano Fault can be considered as the most tectonically active fault in the Vallo di Diano Fault System. By calculating Coulomb stress changes, we have constrained modes of mechanical interactions between the two faults in a scenario compatible with the 1561 earthquake. This approach allows us to argue that both the Caggiano and the Polla Faults are probably linked at depth, and part of the same seismogenic structure which may be potentially responsible for composite ruptures with magnitude ≥ 6.5.  相似文献   

15.
The relationships between thrusts and normal faults represent primary constraints in the reconstruction of the modes and timing of pre-, syn- and post-orogenic deformation events in fold-and-thrust belts. Such relationships are well exposed in curved orogenic belts where the thrusts are oblique to the trend of normal faults.We study the NNE–SSW-trending Olevano-Antrodoco-Sibillini oblique thrust and its crosscutting relationships with NW–SE-trending normal faults in order to constrain the Neogene–Quaternary deformation history of the Central-Northern Apennine (Italy). The analysis of structural and geological data allowed us to reconstruct the geometric and kinematic constraints of two inversion events: 1 – During the Pliocene, positive inversion reactivated the NNE–SSW-trending pre-existing Ancona-Anzio normal fault as the Olevano-Antrodoco-Sibillini oblique thrust ramp and caused the shortcut of NW–SE-oriented normal faults; 2 – During the Quaternary, negative inversion reactivated NW–SE-trending pre-thrusting normal faults.The growth of the NW–SE Quaternary normal faults causes seismicity and is responsible of the development of wide Quaternary intramontane basins. Their distribution and the related seismicity have been controlled and compartmentalized by NNE–SSW-trending oblique thrusts. Thus, the crosscutting relationships between thrusts and normal faults are crucial in seismic hazard assessment.  相似文献   

16.
Examples are presented of three temporal relationships between joints and faults: joints that pre-date faults; joints that are precursors to, or synchronous with, faults; and joints that post-date faults. Emphasis is placed on strike-slip faults in carbonate beds, but other examples are used. General rules are given for identifying the three temporal relationships between joints and faults. Joints that formed before faults can be dilated, sheared or affected by pressure solution during faulting, depending on their orientation in relation to the applied stress system. Faulted joints can preserve some original geometry of a joint pattern, with pinnate joints or veins commonly developing where faulted joints interact. Joints formed synchronously with faults reflect the same stress system that caused the faulting, and tend to increase in frequency toward faults. In contrast, joints that pre- or post-date faults tend not to increase in frequency towards the fault. Joints that post-date a fault may cut across or abut the fault and fault-related veins, without being displaced by the fault. They may also lack dilation near the fault, even if the fault has associated veins. Joints formed either syn- or post-faulting may curve into the fault, indicating stress perturbation around the fault. Different joint patterns may exist across the fault because of mechanical variations. Geometric features may therefore be used in the field to identify the temporal relationships between faults and joints, especially where early joints affect or control fault development, or where the distribution of late joints are influenced by faults.  相似文献   

17.
This article is devoted to evaluating destructive earthquakes (magnitude >6) of Iran and determining properties of their source parameters. First of all, a database of documented earthquakes has been prepared via reliable references and causative faults of each event have been determined. Then, geometric parameters of each fault have been presented completely. Critical parameters such as Maximum Credible Rupture, MCR, and Maximum Credible Earthquake, MCE, have been compiled based on the geometrical parameters of the earthquake faults. The calculated parameters have been compared to the maximum earthquake and the surface rupture which have been recorded for the earthquake faults. Also, the distance between the epicenter of documented earthquake events and their causative faults has been calculated (the distance was less than 20 km for 90% of the data). Then, the distance between destructive earthquakes (with the magnitude more than 6) and the nearest active fault has been calculated. If the estimated distance is less than 20 km and the mechanism of the active fault and the event are reported the same, the active fault will be introduced as a probable causative fault of that earthquake. In the process, all of the available geological, tectonic, seismotectonic maps, aerial geophysical data as well as remote sensing images have been evaluated. Based on the quality and importance of earthquake data, the events have been classified into three categories: (1) the earthquakes which have their causative faults documented, (2) the events with magnitude higher than 7, and (3) the events with the magnitude between 6 and 7. For each category, related maps and tables have been compiled and presented. Some important faults and events have been also described throughout the paper. As mentioned in this paper, these faults are likely to be in high seismic regions with potential for large-magnitude events as they are long, deep and bound sectors of the margins characterized by different deformation and coupling rates on the plate interface.  相似文献   

18.
付广  杨敬博 《地球科学》2013,38(4):783-791
为了研究南堡凹陷中浅层油气成藏规律, 采用区域性盖层厚度与断裂断距大小比较和与油气分布关系分析的研究方法, 对断盖配置对沿断裂运移油气的封闭作用进行了研究.结果表明: 断盖配置对沿断裂运移油气有3级封闭作用: (1)当盖层厚度大于断裂断距, 且断接厚度大于一定值时, 盖层与断裂配置对沿断裂运移油气可起完全封闭作用; (2)当盖层厚度大于断裂断距, 但断接厚度小于一定值时, 断盖配置对沿断裂运移油气可起部分封闭作用; (3)当盖层厚度小于断距, 断接厚度小于零时, 断盖配置对沿断裂运移油气无封闭作用.南堡凹陷3套区域性盖层中东二段泥岩和馆三段火山岩2套区域性盖层与断裂配置对沿断裂运移油气均具有完全、部分和无封闭三级作用, 明下段泥岩区域性盖层与断裂配置仅具完全封闭作用.3套区域性盖层与断裂配置的封闭作用之间, 空间不同配置对南堡凹陷中浅层油气聚集分布层位和区域的控制作用主要表现在以下3个方面: (1)南堡2号地区东二段区域性盖层与断裂配置为完全封闭, 油气主要分布在其下; (2)南堡1~5区块东二段区域性盖层与断裂配置为部分或无封闭, 馆三段区域性盖层与断裂配置为完全封闭, 油气主要分布在东一段和馆四段; (3)南堡1号和4号局部地区东二段和馆三段区域性盖层与断裂配置为部分或无封闭, 明下段区域性盖层与断裂配置为完全封闭, 油气从下至上皆有分布.   相似文献   

19.
走滑断裂带对中国西部压扭性叠合盆地大中型油气田形成与分布具有重要的控制作用,也是研究难点之一.基于高密度三维地震资料,本文采用多种地震构造解析技术,瞄准噶尔盆地腹部侏罗系开展了精细走滑断裂带解释和变形样式分析.在燕山Ⅱ幕构造活动期,侏罗系发育了NWW向左行压扭性和NE向左行张扭性两类走滑断裂带.它们都是由4组剪切断层复合而成,共同遵从左行简单剪切模式,但几何学特征和构造属性差异很大.NWW和NE向走滑断裂带不存在共轭剪切关系,而是在钝夹角区(135°左右)普遍具有弧形联合与归并趋势.在构造变形中,两类同期左行走滑断裂带弧形联合控制了变形区域旋扭形变和剪切破裂,构成了一个大尺度“面”状旋扭构造体系.旋扭构造变形样式对中亚陆内造山带研究具有一定借鉴意义,也为压扭盆地的油气勘探实践提供了新思路.   相似文献   

20.
古城低凸起是塔里木盆地东部地区的重要勘探领域,古城6、8、9井的相继成功证实了其良好的勘探前景。塔里木盆地多年勘探实践表明,断裂对储层的形成和成藏有着重要的控制作用,对于油气发现具有重要意义。本文立足于本区二、三维地震资料,从分析断裂剖面的几何特征入手,建立了古-中生代的断裂发育样式,结合多窗口倾角扫描技术识别了隐蔽走滑断裂的平面特征,系统剖析了不同演化阶段断裂的变形机制,详细研究了构造演化对油气成藏的影响。研究表明:古城地区主要发育7类不同断层的构造样式,包括张性正断层、张扭性负花状构造、正"Y"字形构造、反"Y"字形构造、压扭性正花状构造、近直立的共轭走滑断层及张扭性走滑正断层;平面上主要发育NW向、NE向和NNE向3个方向的断裂。根据断裂的几何要素和动力特征,将断裂活动期次分为早加里东期、中加里东期、晚加里东-早海西期和印支-燕山期。其中:中加里东期断层奠定了本区堑垒相间的构造格局,是油气和下部流体向上运移重要通道;印支-燕山期形成的"羽状"断裂带是晚加里东-早海西期断裂再次活化形成的,距离其在3.0 km以内的井普遍钻探效果较差,对成藏有着重要的破坏作用。  相似文献   

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