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黔西南泥堡金矿床属于滇黔桂"金三角"地区的大型微细浸染型金矿床之一,是非岩浆热液成矿作用的典型代表。通过对泥堡金矿区开展1∶10000大比例尺构造-蚀变填图,查明了与金矿化密切相关的硅化、褐铁矿化、黄铁矿化及少量萤石化、毒砂化、辉锑矿化、方解石化等围岩蚀变的空间展布规律,厘定了矿区控矿构造格架为F1逆冲断层及其牵引形成的二龙抢宝背斜,以及枢纽北西向与北东向褶皱叠加所形成的穹隆构造。并据此提出了泥堡金矿找矿靶区,即位于玉家坪以南的乡道旁、次级逆断层与背斜构造组合样式发育区。 相似文献
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根据高陂煤矿区主要断层的走向、形成期次、平面展布样式和发育特征,分析了该区应力状态及矿区构造演化过程。研究表明:在矿区北东、南西向局部主压应力作用下,产生了南部一系列逆冲断层和褶曲,同时在这种压应力持续作用下,又产生了与局部主压应力几乎垂直的北西、南东向的张应力,从而进一步产生了低序次的北东—南西向张断裂;该区在印支晚期主要形成了3条滑覆断层,燕山早期形成了高陂向斜、矿区东西边界断层、次一级褶曲和小断层;燕山中、晚期形成了矿区南北边界断层,并使高陂向斜南高北低。 相似文献
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基于物探、钻探等资料,采用地质统计法对东欢坨矿区构造要素进行分析,探讨了断层发育规模、空间展布特征及断层要素与断层性质的相关关系,建立了不同性质断层的落差与延展长度之间的经验公式,从古构造应力场演化角度分析了断裂展布的成因。研究表明：区内地质构造以NE向断层为主,以车轴山向斜轴为界,表现为＂两翼分区＂、＂西逆东正＂,全区呈现＂南北分带＂、＂南密北稀＂的展布特征。定量分析认为断层落差与延伸长度呈正相关关系,断裂密度等值线呈现明显分区性,断裂强度由SE-NE逐渐减弱。 相似文献
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根据冯记沟矿区主要构造的走向、形成期次、平面展布规律,分析了该区应力状态及构造演化,总结了矿区构造特征、地质应力作用与构造赋存规律的关系。认为矿区经受过多期地质构造运动的破坏,整体表现为一系列走向近南北向褶皱群以及与之相伴的断层构造。由于受较强烈的近东西向挤压,总体为一西翼窄、东翼宽缓的不对称背斜构造（尖儿庄背斜）,北端翘起、向南倾伏,被断层切割呈“簸箕状”。断裂多表现为高角度逆冲断层。从各种构造的切割关系分析,在东西向主压应力作用下．发育了一系列的近南北向的逆冲断层以及褶皱（矿区北部的尖儿庄背斜、马家滩向斜、冯记沟背斜等）,同时还派生了与主压应力相互垂直的右行平移正断层（DF2）及北东向的斜交逆断层（DF3）。 相似文献
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淮南顾桥煤矿层滑构造形成机制探讨 总被引：1，自引：0，他引：1
通过对淮南顾桥煤矿构造应力场解析及工作面层滑构造等引起的异常区展布统计分析,并结合模拟实验手段,对顾桥矿区层滑构造形成机制进行了探讨。研究认为,顾桥矿区印支期以来至少经历了2期挤压构造应力场作用;工作面发育顶底皆断、顶断底不断和底断顶不断3种类型的正断层,层滑变薄区和正断层呈近东西方向展布;近东西方向的挤压应力场是形成顾桥矿层滑构造的力学机制。模拟实验表明,层滑变薄区展布与伸展方向近于垂直,正断层是层滑变薄区的边界,层滑变薄区具有成带性、方向性和间隔性。 相似文献
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Xiang Wang 《Journal of Structural Geology》1995,17(12)
Initially planar fault surfaces can be refracted by differential compaction, sudden changes in the displacement gradient taking place at the contact of different lithologies. As a result, the original displacement pattern, e.g. a cone-type in an idealized case, can be changed into a zigzag-type, especially when the initial dip angle of the fault and differential compaction are high. Compared with pre- and syn-faulting compaction, post-faulting compaction is more likely to change the initial displacement pattern along normal faults which were active near the sediment surface. Based upon the assumption that compaction is homogeneous vertical strain, the original fault geometry and displacement pattern can be estimated by means of decompaction and related geometric calculations. 相似文献
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野外地质调查和剖面测量揭示:郁江断层带的轨迹结构整体上表现为南北分段、东西分带的后展式叠瓦状逆冲断层结构;其中,底板缓倾角逆冲断层多层次(区域尺度、露头尺度和微观尺度)的断坪、断坡轨迹,特别是沿断坡方向的破裂分解,是分支断层呈上叠后展式扩展增殖的基础。根据运动学标志,郁江逆冲断层从北西向南东逆冲,最大断距小于1km,一般断距为10～100m级;后缘高倾角正断层的累计断距与前缘逆冲断距基本对应。结合区域构造分析,郁江逆冲断层轨迹结构定型于燕山期,轨迹扩展过程表现为:上叠分支断层沿底板逆冲断层的断坡方向逐次从前缘向后缘扩展增殖,属于典型的上叠后展式逆冲扩展结构;其中,后缘正断层的形成是断层轨迹结构反馈、运动调整和断层自组织行为的必然结果;而喜马拉雅主期区域应力场的激发,只是强化和加速了后缘正断层的扩展规模和进程。 相似文献
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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
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用地面露头、地震和CEMP(连续电磁剖面法)勘探资料揭示的库车坳陷-南天山盆山过渡带构造变形特征难以用经典的“A型俯冲”冲断褶皱楔变形模型来解释,因而文中提出一种“分层变形、垂向叠置”的“非俯冲”收缩构造解释模型。所谓分层变形是指受古近系膏盐岩层和侏罗系含煤地层等软弱岩层分隔,不同深度的岩层发育不同的收缩变形样式;所谓垂向叠置是指不同层次的强变形带在垂向上叠置,不存在区域性大位移的拆离断层。位于盐岩层之上的新生界以滑脱褶皱变形为主,而盐下层的中生界沉积层及盆地基底则以收缩断裂变形为主。浅部的滑脱褶皱表现出紧闭背斜和宽缓向斜组合,背斜具有不对称形态,其核部在古近系盐岩层或侏罗系含煤地层中滑脱,可在陡翼发育破冲断层或缓翼发育顺层滑脱逆冲断层。深层断裂变形以向山脉倾斜的高角度基底卷入逆冲断层为主干断层,断层上盘形成冲断隆起,次级断层相对较少,下盘则发育一系列同向倾斜的次级逆冲断层构成楔状叠瓦冲断构造。深层断层向上延伸在古近系盐岩层中尖灭,部分次级断层向下延伸并在侏罗系含煤地层中或盆地基底面滑脱,但是主干逆冲断层高角度切入基底,向上则对应于浅层背斜的核部。基底卷入的高角度主干逆冲断层可能利用了先存正断层发生反转位移,并成为控制局部构造变形的主要构造要素。天山上升引起的垂直剪切作用是导致库车坳陷-南天山盆山过渡带发育高角度逆冲断层或促成先存正断层的反转的可能原因。 相似文献
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倾斜断层Vzz、Vzzz的联合反问题解 总被引：1，自引：0，他引：1
本文利用两个上延高度的Vzz极值距和其中之一高度的Vzzz的零值点获得了倾斜断层的位置、埋深、断距、倾向、倾角以及断层正逆性质等的反问题解。 相似文献
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《International Geology Review》2012,54(2):133-144
The Wagner basin occupies the northernmost spreading centre in the Gulf of California, located along the Pacific‐North America plate boundary. It is filled with sediments from the Colorado River that obscure its bathymetric expression; therefore it is not as well defined as other basins in the central and southern Gulf of California. To define the geometry and extension of the Wagner basin, a 2D multi‐channel seismic reflection database was used. Data were collected by Petroleos Mexicanos (PEMEX) in 1979–1980. The most important regional structural features identified are the Consag and Wagner normal faults and the Cerro Prieto strike‐slip fault. These structures play an important role in the development of the basin. The Consag fault, described for the first time in this paper, marks the western side of the basin. The eastern and northwest limits are bound by the Cerro Prieto and Wagner faults respectively. The Wagner fault intersects the Cerro Prieto fault at an angle of 130°, bending the depocentre in a NW direction, adjacent to the Cerro Prieto fault zone. The northernmost segment of the Consag fault bends 25° in a NE direction and joins the Cerro Prieto fault at an angle of 110°. Greater subsidence (up to 300 m) takes place along the northern trace of the Cerro Prieto fault, with a downthrown displacement of 400 m. The Consag and Wagner breaks obliquely intersect the Cerro Prieto fault, and, inasmuch as both are normal faults, they have small horizontal slip components which generated oblique displacement. This structural pattern is different relative to the pattern of basins located south of Wagner basin, such as the Upper and Lower Delfin basins. The orientations of the normal faults are perpendicular to the master fault (Ballenas transform fault). The relationship between normal and transform faults in the Wagner basin and the observed ‘S’ shape are typical of a basin that has not yet reached maturity. As a result of this study, the previously uncertain area (～1330 km2) and perimeter (158 km) of the Wagner basin were defined. 相似文献
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The solution of two-dimensional problem of an interface breaking long inclined dip-slip fault in two welded half-spaces is
well known. The purpose of this note is to obtain the corresponding solution for a blind fault. The solution is valid for
arbitrary values of the fault-depth and the dip angle. Graphs showing the variation of the displacement field with the distance
from the fault, for different values of fault depth and dip angle are presented. Contour maps showing the stress field around
a long dip-slip fault are also obtained 相似文献
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The Schlinig fault at the western border of theÖtztal nappe (Eastern Alps), previously interpreted as a west-directed thrust, actually represents a Late Cretaceous, top-SE to -ESE normal fault, as indicated by sense-of-shear criteria found within cataclasites and greenschist-facies mylonites. Normal faulting postdated and offset an earlier, Cretaceous-age, west-directed thrust at the base of theÖtztal nappe. Shape fabric and crystallographic preferred orientation in completely recrystallized quartz layers in a mylonite from the Schlinig fault record a combination of (1) top-east-southeast simple shear during Late Cretaceous normal faulting, and (2) later north-northeast-directed shortening during the Early Tertiary, also recorded by open folds on the outcrop and map scale. Offset of the basal thrust of theÖtztal nappe across the Schlinig fault indicates a normal displacement of 17 km. The fault was initiated with a dip angle of 10° to 15° (low-angle normal fault). Domino-style extension of the competent Late Triassic Hauptdolomit in the footwall was kinematically linked to normal faulting.
The Schlinig fault belongs to a system of east- to southeast-dipping normal faults which accommodated severe stretching of the Alpine orogen during the Late Cretaceous. The slip direction of extensional faults often parallels the direction of earlier thrusting (top-W to top-NW), only the slip sense is reversed and the normal faults are slightly steeper than the thrusts. In the western Austroalpine nappes, extension started at about 80 Ma and was coeval with subduction of Piemont-Ligurian oceanic lithosphere and continental fragments farther west. The extensional episode led to the formation of Austroalpine Gosau basins with fluviatile to deep-marine sediments. West-directed rollback of an east-dipping Piemont-Ligurian subduction zone is proposed to have caused this stretching in the upper plate. 相似文献
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Abstract: A fault is not simply a plane, but a zone consisting of a series of broken planes or lower faults. The greater the scale of faults, the wider and more complex the fault zone is. Fault-sealing properties are influenced by the fault zone itself, whose fault displacement, depth, net-to-gross-ratio of mudstone, fault plane angle, and fault mechanical properties play important controlling roles. The sealing of hydrocarbon by the fault zone depends on whether the fault zone can form a continuous sealing zone and if the pore throats connecting those fault zones are small enough. The concept of fault zone-sealing potential is proposed here, and a quantitative formula is established by using a great amount of practical statistical data as well as the fuzzy comprehensive evaluation method, which is a comprehensive characterization parameter to judge whether or not fault zones could seal oil hydrocarbon. The greater the value of the fault zone-sealing potential, the better sealed the fault is. For example, with increasing depth, the sealing degree of the Xin 68 Fault in the Dongxin 1 oilfield changes greatly, reflecting the complexity of fault-sealing properties. 相似文献