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1.
下扬子地区中新生代构造变形单元及构造变形样式 总被引：1，自引：0，他引：1
下扬子地区地处扬子板块东部,其构造变形特征研究具有重要意义。综合利用区域地质、地震、钻井和地球物理等多方面资料,对下扬子地区断裂、地层发育特征精细解释,建立了贯穿研究区的两条区域地质剖面,即宿迁绍兴大剖面和连云港苏州大剖面。研究表明:下扬子地区可划分为6个一级构造变形单元,依次为苏北胶南造山带、苏北冲断区、南北对冲带、苏南冲断区、浙北冲断区和江南造山带,并可进一步细分为14个二级构造变形单元,这些明确表现出本区中、新生代对冲构造变形特征;两条区域大剖面表现出了挤压、伸展、反转等3类典型构造变形样式,具体可分为5亚类、10小类。 相似文献
2.
柴北缘锡铁山地区滩间山群构造变形分析 总被引：2，自引：0，他引：2
初步构造变形分析表明 ,柴北缘锡铁山地区的早古生代变质火山岩系 -滩间山群在加里东期碰撞造山过程中经历了两期构造变形 :第一期为垂直造山带的挤压缩短变形 ,形成一系列紧闭褶皱、区域片理和大型韧性剪切带 ;第二期为平行造山带的挤压缩短变形 ,形成区域透入性共轭破劈理或膝折带。这两期变形是柴北缘加里东期碰撞造山带的斜向碰撞造山过程中不同阶段变形特征的体现。这种构造型式可能对于认识斜向碰撞造山带的构造动力学的转换过程具有重要意义。 相似文献
3.
下扬子区是中国东部重要的含油气盆地区之一,其新生代伸展构造变形一直是下扬子新生代构造动力学的核心问题.通过对下扬子海陆全区新生代断陷盆地结构与构造格局分析,明确了下扬子区伸展构造变形特征,探讨了变形成因机制及其区域构造意义.区域构造分析表明,下扬子区伸展变形构造由一系列NNE-NE-NEE走向的总体呈弧形展布的正断层构成,表现为受伸展断裂系统控制的断陷结构,具有多向伸展特征,自南向北可分为江南、沿江-苏北-南黄海和南黄海北部3个构造伸展区.有限元数值与构造物理模拟表明,受控于太平洋板块俯冲推挤传递至陆内的侧向构造作用力,下扬子块体南向蠕移,区域上近南北向伸展变形,郯庐断裂右旋走滑,两者共同构成一个"右旋侧向扩展变形"系统.在区域构造上,大兴安岭-太行山-武陵山重力梯度带以东的中国东部新生代伸展变形构造和盆地成因与古太平洋板缘边界条件密切相关. 相似文献
4.
郭进京 《前寒武纪研究进展》2000,23(3):147-152
初步构造变形分析表明,柴北缘锡铁山地区的早古生代变质岩系－滩间山群在加里东期撞造山过程中经历了两期构造变形：第一期为垂直造山带的挤压缩短变形,形成一系列紧闭褶皱、区域片理和大型韧性剪切带;第二期为平行造山带的挤压缩短变形,形成区域透入性共轭破劈理或膝折带。这两期变形是柴北缘加里东期碰撞造山带的斜向碰撞造山过程中不同队段变形特征的体现。这种构造式可能对于认识斜向碰撞造山过程中不同阶段变形特征的体现。 相似文献
5.
江南断裂构造属性及成生环境初探 总被引：2，自引：1，他引：1
江南断裂作为江南隆起带北缘边界的区域性断裂,时空变形特点表现为前燕山期非造山性质的沉积相突变带和燕山期具造山性质的构造变形带。突变带内同生角砾岩仅具相带划分意义。构造变形带内江南断裂中浅层宏观总体表现逆冲断层;地质证据和ESR年龄证据表明断裂作用起始于燕山早期,持续至喜山早期;宏微观构造、包体测温和差异应力等综合研究显示断层总体处于脆性、低温、低差异应力构造变形环境。但江南断裂现今中浅层主要变形形迹和成生条件所表现的构造属性与空间断层性质不相对应,原因可能与中浅层构造变形样式、基底变形特征及区域应力作用特点有关。 相似文献
6.
燕山板内造山带中部承德盆地复杂的中生代褶皱及逆冲断裂构造,曾被解释为土城子组沉积之后大型逆冲推覆构造(位移量大于40～45km)又经褶皱变形的结果。近年来,土城子组沉积相和物源区分析、中新元古界沉积古地理研究以及相关构造变形研究结果等,对这一变形大型逆冲构造模型提出了多方位质疑。但已有研究并未提出新的构造模型来解释这一复杂构造区域中生代构造变形样式和形成机制。文中通过对承德盆地区域主体构造——承德向斜、向斜两翼逆冲构造变形几何学与运动学特征、向斜转折端附近构造变形与断裂发育状况进行详细野外调查及对关键地质体同位素地质年代进行测试,发现承德向斜两翼逆冲断层为分别向向斜核部以外区域逆冲的独立逆冲断层,逆冲断层活动与承德向斜变形是在统一的收缩变形体制下准同时形成的。它们形成于土城子组之后、张家口组火山活动之前,即距今约139～136 Ma。据此提出了"承德逆冲构造"的背离向斜逆冲构造模型。这一模型合理地解释了燕山中部承德盆地区域中生代构造变形和相应的盆地充填特征,同时表明,燕山板内造山带并不存在碰撞造山带前陆褶皱逆冲带中常见的大型薄皮逆冲构造样式。这一研究结果展示了褶皱相关断裂构造模型在研究和揭示收缩构造变形区域大尺度褶皱与断裂构造相互关系及准确重建区域构造演化过程方面的重要意义。 相似文献
7.
造山带主要发育在板块边界或邻近板块边界的活动大陆边缘以及陆内裂陷带。平卧格皱伴随韧性剪切带是活动大陆边缘造山带典型的区域构造样式。轴面陡立或刨转扇形格皱伴随道冲断裂是陆内裂陷造山带的构造标志。往往由于经历过多期的构造变形和后天构造的干扰，不能直接辨认造山带的原始构造样式和方位。因此，需要进行系统观测—，明辨变形形迹及其世代关系，分别获取必需的产状数据，因地制宜地进行构造解析，恢复造山带初始的构造样式及其方位，为鉴别它的构造环境性质和编制大陆块体的构造格架图提出可靠的依据。 相似文献
8.
以现有地质及地震资料为基础,对阿姆河右岸区块东南部靠近吉萨尔山前地区的中下侏罗统主要构造特征进行探讨,一方面有利于促进该区中下侏罗统油气勘探,同时也有利于深化对造山带向盆地过渡的山前地区构造变形规律的认识。研究表明：该区中下侏罗统整体表现为由三列近似呈雁行状排列的NE向背斜带组成的褶皱-冲断构造。从控制背斜构造发育的断裂活动特征看,东部山前断层表现为由南东向北西方向逆冲,活动强度大,向西逆断层运动的强度逐渐减弱,且由南向北西部断层的逆冲运动方向发生反向变化,在研究区的北部发育典型的构造三角带。西部背斜带可视为断裂运动方式由南向北变化导致的调节构造。沿构造带走向,三列背斜构造高点由南向北逐渐升高。通过对中下侏罗统构造变形与上覆地层构造特征的比较,结合该区侏罗系沉积特征,认为中下侏罗统构造变形是与上覆地层构造变形共同形成于新近纪喜山期统一的区域构造运动背景下。其主要构造变形机制是晚古近-新近纪以来,在印度板块、阿拉伯板块和欧亚板块碰撞远程效应影响下,受吉萨尔山脉的隆升挤压和研究区北部NW向的大型断裂如布哈拉断裂、曼格什拉克断裂的右旋压扭共同作用而成。 相似文献
9.
从西南天山超高压变质带多期构造变形看天山古生代构造演化 总被引：2，自引：1，他引：1
通过对西南天山阿克雅孜和木扎尔特地区高压-超高压变质带构造几何学和岩石变形相关运动学的详细剖析,厘定出高压-超高压变质岩石及其相关围岩的构造单元。详细研究表明,研究区可划分为三个构造单元:北部单元、中部单元和南部单元。确定了每个构造单元的构造几何学特征及各个构造单元之间的相互关系。通过分析岩石变形特征和叠加关系,确定了岩石所记录多期变形的运动学特征。根据研究区的多期构造变形特点,建立了阿克雅孜和木扎尔特河地区构造演化序列。共划分出四期构造可识别的事件(E1-E4),分别代表了E1:高压-超高压岩石折返过程;E2:高压-超高压岩石造山带的早期改造过程;E3:北部构造事件对高压-超高压造山带影响;E4:走滑构造对高压-超高压造山带的叠加。沿造山带系列构造分析表明,西南天山高压-超高压带中发育的四期构造事件沿中天山北缘具有很好的一致性,各期构造事件也有一定的横向可对比性。在此基础上通过对多期变形事件的构造背景的探讨,建立了整个天山在古生代的构造拼合过程,揭示我国西部洋壳相关的深俯冲造山带形成过程和参与深俯冲作用(超)高压变质岩的变形变质历史。 相似文献
10.
显微构造变形热年代学是一种新兴的研究构造变形热年代学方法,能够解决一些常用方法无法解决的或很困难的构造问题。显微构造变形热年代学利用因构造变形事件而产生的新生矿物结晶年龄来测定小至一般的构造变形,大至区域构造乃至造山带或碰撞带构造变形的年龄,建立构造演化时间序列,并可以计算其变形速率或隆升速率。 相似文献
11.
Yang Chu Michel Faure Wei Lin Qingchen Wang Wenbin Ji 《International Journal of Earth Sciences》2012,101(8):2125-2150
In orogenic belts, a basal décollement zone often develops at depth to accommodate the shortening due to folding and thrusting of the sedimentary cover. In the Early Mesozoic intracontinental Xuefengshan Belt of South China, such a décollement zone is exposed in the core of anticlines formed by the emplacement of the late-orogenic granitic plutons. Our detailed, multi-scale structural analysis documents a synmetamorphic ductile deformation. In the basal décollement, the Neoproterozoic pelite and sandstone, and the intruding Early Paleozoic granites were deformed and metamorphosed into mylonites and orthogneiss, respectively. The metamorphic foliation contains a NW–SE stretching lineation associated with top-to-the-NW kinematic indicators. The ductile shearing of these high-strained rocks can be correlated with NW-verging folds and thrusts recognized in the Neoproterozoic to Early Triassic sedimentary cover. Monazite U–Th–Pbtot chemical dating, and zircon SIMS U–Pb dating provide age constraints of the ductile shearing between 243 and 226?Ma, and late-orogenic granite emplacement around 235–215?Ma. In agreement with recent geochronological data, these new results show that the Xuefengshan Belt is an Early Mesozoic orogen dominated by the NW-directed shearing and thrusting. At the southeastern boundary of the Xuefengshan Belt, the Chenzhou-Linwu fault separates the Early Mesozoic domain to the NW from the Early Paleozoic domain to the SE. The tectonic architecture of this belt was possibly originated from the continental underthrusting to the SE of the South China block in response to northwest-directed subduction of the Paleo-Pacific plate. 相似文献
12.
华南板块早中生代陆内造山过程——以雪峰山-九岭为例 总被引：3，自引：1，他引：2
雪峰山-九岭造山带位于华南板块的中心区域,是一条典型的陆内造山带。通过详细的野外地质观察,雪峰山在早中生代经历了3期构造变形:D1为上部指向NW的韧性剪切,D2代表了一期反向褶皱-逆冲构造事件,以及D3期的水平挤压形成的直立的褶皱、劈理和线理。而在九岭,早中生代大规模脆-韧性域构造变形叠加在早古生代韧性变形之上,形成了一系列极性NW逆冲断层和不对称褶皱。雪峰山-九岭陆内造山带形成于早中生代,造山作用可以分为两个阶段,即245~225Ma的挤压变形阶段和225~215Ma的垮塌-岩浆侵位阶段。雪峰山-九岭造山带的构造特点表明,华南板块东南缘古太平洋板块向北西方向的俯冲可能引发了早中生代的陆内造山过程。 相似文献
13.
Structural Mapping of the Bentong‐Raub Suture Zone Using PALSAR Remote Sensing Data,Peninsular Malaysia: Implications for Sediment‐hosted/Orogenic Gold Mineral Systems Exploration 
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下载免费PDF全文 The Bentong‐Raub Suture Zone (BRSZ) of Peninsular Malaysia is one of the major structural zones in Sundaland, Southeast Asia. It forms the boundary between the Gondwana‐derived Sibumasu terrane in the west and Sukhothai Arc in the east. The BRSZ is genetically related to the sediment‐hosted/orogenic gold deposits associated with the major lineaments in the Central Gold Belt of Peninsular Malaysia. In this investigation, the Phased Array type L‐band Synthetic Aperture Radar (PALSAR) satellite remote sensing data were used to map major geological structures in Peninsular Malaysia and provide detailed characterization of lineaments and curvilinear structures in the BRSZ, as well as their implication for sediment‐hosted/orogenic gold exploration in tropical environments. Major structural lineaments such as the Bentong‐Raub Suture Zone (BRSZ) and Lebir Fault Zone, ductile deformation related to crustal shortening, brittle disjunctive structures (faults and fractures) and collisional mountain range (Main Range granites) were detected and mapped at regional scale using PALSAR ScanSAR data. The major geological structure directions of the BRSZ were N–S, NNE–SSW, NE–SW and NW–SE, which derived from directional filtering analysis to PALSAR fine and polarimetric data. The pervasive array of N–S faults in the Central Gold Belt and surrounding terrain is mainly linked to the N–S trending of the Suture Zone. N–S striking lineaments are often cut by younger NE–SW and NW–SE‐trending lineaments. Gold mineralized trend lineaments are associated with the intersection of N–S, NE–SW, NNW–SSE and ESE–WNW faults and curvilinear features in shearing and alteration zones. Compressional tectonic structures such as the NW–SE trending thrust, ENE–WSW oriented faults in mylonite and phyllite, recumbent folds and asymmetric anticlines in argillite are high potential zones for gold prospecting in the Central Gold Belt. Three generations of folding events in Peninsular Malaysia have been recognized from remote sensing structural interpretation. Consequently, PALSAR satellite remote sensing data is a useful tool for mapping major geological structural features and detailed structural analysis of fault systems and deformation areas with high potential for sediment‐hosted/orogenic gold deposits and polymetallic vein‐type mineralization along margins of Precambrian blocks, especially for inaccessible regions in tropical environments. 相似文献
14.
《International Geology Review》2012,54(8):876-906
The synorogenic basins of central Cuba formed in a collision-related system. A tectono-stratigraphic analysis of these basins allows us to distinguish different structural styles along the Central Cuban Orogenic Belt. We recognize three distinct structural domains: (1) the Escambray Metamorphic Complex, (2) the Axial Zone, and (3) the Northern Deformation Belt. The structural evolution of the Escambray Metamorphic Complex includes a latest Cretaceous compressional phase followed by a Palaeogene extensional phase. Contraction created an antiformal stack in a subduction environment, and extension produced exhumation in an intra-arc setting. The Axial Zone was strongly deformed and shortened from the latest Cretaceous to Eocene. Compression occurred in an initial phase and subsequent transpressive deformation took place in the middle Eocene. The Northern Deformation Belt consists of a thin-skinned thrust fault system formed during the Palaeocene to middle Eocene; folding and faulting occurred in a piggyback sequence with tectonic transport towards the NNE. In the Central Cuban Orogenic Belt, some major SW–NE structures are coeval with the Cuban NW–SE striking folds and thrusts, and form tectonic corridors and/or transfer faults that facilitated strain-partitioning regime attending the collision. The shortening direction rotated clockwise during deformation from SSW–NNE to WSW–ENE. The synchronicity of compression in the north with extension in the south is consistent with the opening of the Yucatan Basin; the evolution from compression–extension to transpression is in keeping with the increase in obliquity in the collision between the Caribbean and North American plates. 相似文献
15.
大巴山与雪峰山逆冲构造带J3-K1复合过程的响应———鄂西秭归褶皱带构造样式与形成机制 总被引：1，自引：0，他引：1
秭归褶皱带位于大巴山逆冲带与雪峰山逆冲带叠合部位,总体呈现穹窿-盆地型式,是构造复合、联合作用的结果,记录了大巴山逆冲带与雪峰山逆冲带两者相互作用的重要信息,是研究构造复合和联合过程的理想区域。本文通过对秭归褶皱带秭归向斜、巴东复向斜和香龙山背斜的野外调查,对褶皱枢纽、相关断层、节理等进行详细构造解析,理清了先后叠加关系,在此基础上进行了构造分期和配套,对变形期古构造应力场进行了恢复重建。结果表明秭归褶皱带晚侏罗世-早白垩世经历三期构造变形:D1期以近EW向的秭归向斜和香龙山背斜为代表,秭归向斜为轴面近直立的开阔圆弧状,香龙山背斜呈轴面近直立的箱状,相关逆冲断层具由北向南逆冲的特点,可能与大巴山由NE向SW逆冲作用有关。D2期秭归向斜叠加近SN向枢纽,呈锅状,香龙山背斜东段发育鼻状的五龙背斜,褶皱带呈穹窿-盆地型。与向斜相关的水田坝断裂带向SEE逆冲,主压应力场呈NWW-SEE近平行的束状。该期变形可能与雪峰山逆冲带向NW逆冲过程中受到黄陵背斜阻挡有关。D3期秭归向斜近SN向枢纽向南西弯曲,巴东复向斜呈NW凸出弧形,香龙山背斜西端叠加NE-SW向构造形迹。主压应力场总体向NW发散。该期变形可能与雪峰山逆冲带向NW逆冲推挤有关。上述构造分析表明,向SW逆冲的大巴山逆冲带先影响鄂西地区,之后向NW逆冲推挤的雪峰山逆冲带扩展至该地区,形成复合关系。区域构造与地层关系分析表明D1-D3形成于J3-K1,因此秭归褶皱带是大巴山逆冲构造带向SW叠瓦逆冲并与指向NW的雪峰山逆冲带复合叠加的结果,表明上扬子地区在J3-K1经历了分阶段复合叠加的过程,即前期受到大巴山逆冲带近SN构造作用影响,后期经历向NW逆冲推挤的雪峰山逆冲带NW-SE向构造叠加。 相似文献
16.
雪峰隆起是扬子准地台与南华褶皱系的分界单元,经历晋宁晚期古隆起、加里东期末局部隆起和中生代全面隆起3个阶段的演化历程,上叠中生代陆相盆地。雪峰山构造带主要为陆内造山带,据变形特征从NW至NE划分为3个平行的NNE-NEE向弧形构造带。呈现出从中深层次韧性、脆韧性-中浅层次韧脆性变形-浅层次脆性变形的变化规律。雪峰山及邻区推滑覆构造十分发育,主要形成于中生代,组成不对称背冲式扇形雪峰推滑覆构造系。雪峰隆起西侧武陵坳陷为被动陆缘区,有下、上两大套海相生储盖组合及加里东期、印支期、中生代等三大油气形成阶段。雪峰山隆起及其邻区侏罗山式褶皱及推覆构造发育,其下可能保存部分残存海相油气藏。 相似文献
17.
The Klondike Schist that forms the basement rocks for the famous Klondike placer goldfield was emplaced as km-scale thrust
slices in Early Jurassic time, along with some thin (10 to 30 m-scale) slices of greenstone and ultramafic rocks. Permian
metamorphic fabrics in the schists were deformed during thrust emplacement by structures formed as the rocks passed through
the brittle–ductile transition. Early-formed thrust-related structures were almost-pervasive recumbent folds that affected
both the schist and greenstone/ultramafic slices and imposed a spaced cleavage with minor recrystallisation of micas. These
structures gave way to shallow-dipping phacoidal cleavage near (within <100 m of) thrust structures. Thrust-related structures
have been overprinted locally by well-defined steeply dipping reverse fault-fold zones, and associated upright folding on
regional (km) to mesoscopic (m) scales. The fold-fault zones occur as two orthogonal sets of structures oriented NW to N and
NE to E. Some of these steeply dipping fault zones have been reactivated by Late Cretaceous normal faulting. Orogenic (mesothermal)
gold-bearing veins were emplaced in local sites of extension during or after formation of the compressional fault-fold zones
and before normal fault reactivation. Over 400 veins (m to cm-scale) observed in this study imply a general NW strike for
mineralised structures (W to N), but with a broad scatter of orientations. Vein emplacement was controlled principally by
fold axial surfaces of kink folds of the fault-fold generation. However, some other local extension sites have opened along
preexisting structures to host veins locally, including metamorphic foliation and spaced cleavage planes. In addition, irregular
extensional fractures with no obvious structural control host some veins. The Klondike mineralised veins formed as swarms
with broad regional structural control, but represent relatively diffuse mineralised zones, with numerous scattered small
veins, compared to most orogenic vein systems. These diffuse vein swarms appear to be sufficient sources for the rich and
geographically localised placer gold deposits that formed in overlying gravels during erosion of the Klondike Schist basement. 相似文献
18.
Differential Tectonic Deformation of the Longmen Mountain Thrust Belt,Western Sichuan Basin,China 总被引：1，自引：1，他引：0
Field investigation and seismic section explanation showed that the Longmen Mountain Thrust Belt has obvious differential deformation: zonation, segmentation and stratification. Zonation means that, from NW to NE, the Longmen Mountain Thrust Belt can be divided into the Songpan-Garzê Tectonic Belt, ductile deformation belt, base involved thrust belt, frontal fold-thrust belt, and foreland depression. Segmentation means that it can be divided into five segments from north to south: the northern segment, the Anxian Transfer Zone, the center segment, the Guanxian Transfer Zone and the southern segment. Stratification means that the detachment layers partition the structural styles in profile. The detachment layers in the Longmen Mountain Thrust Belt can be classified into three categories: the deep-level detachment layers, including the crust-mantle system detachment layer, intracrustal detachment layer, and Presinian system basal detachment layer; the middle-level detachment layers, including Cambrian-Ordovician detachment layer, Silurian detachment layer, etc.; and shallow-level detachment layers, including Upper Triassic Xujiahe Formation detachment layer and the Jurassic detachment layers. The multi-level detachment layers have a very important effect on the shaping and evolution of Longmen Mountain Thrust Belt. 相似文献
19.
The Proterozoic Eastern Ghats Mobile Belt along the east coast of India shares a thrusted lower contact with the surrounding cratons. The thrust, known as the Terrane Boundary shear zone, is associated with two large lateral ramps resulting in a curved outline on the northwestern corner of the mobile belt. The Eastern Ghats Mobile Belt is divided into two lithotectonic units, the Lathore Group and the Turekela Group, based on their lithological assemblages and deformational history. On the basis of published data from a Deep Seismic Sounding (DSS) profile of the Eastern Ghats crust, the Terrane Boundary Shear Zone is considered to be listric in nature and acts as the sole thrust between craton and mobile belt. The Lathore and Turekela Groups are nappes. With this structural configuration the NW part is described as a fold thrust belt. However, the thrusting postdates folding and granulite metamorphism that occurred in the Eastern Ghats, as in the Caledonide type of fold thrust belt of NW Scotland. The Terrane Boundary Shear Zone is interpreted to be contiguous with the Rayner-Napier boundary of the Enderby Land in a Gondwana assembly. 相似文献
20.
Recently acquired 2-D seismic profiles in the offshore area between Bondoc Peninsula and Burias Island, South Luzon, Philippines, are interpreted in the context of known structural styles observed onshore and in relation to paleo- and neo-tectonic regimes in the region. Two distinct seismic sequences can be distinguished relative to their structural style and tectonic significance. The top of a lower sequence shows strongly reflective properties. This unit, correlative to Late Oligocene to Early Miocene limestone bodies observed onshore in Bondoc Peninsula and Burias Island, is affected by intense to moderate superposed folding and thrust faulting. An upper sequence, correlative to a two-member turbiditic and shallower marine clastic deposit widely exposed in Bondoc Peninsula, is affected by thrust faulting and deformation associated with overturned tight folding. The onshore equivalents of these two seismic sequences form the core of a bent anticlinorium that twists from a NW–SE axis in onshore Bondoc into a N–S axis southwards into the southern tip of the peninsula, then back to a NW–SE axis in the offshore region further to the south. Overlying this structural core is a relatively less deformed sequence where syn-sedimentary half-grabens are still preserved in places. This complex structural style is the result of a series of several tectonic events occurring from the Eocene to the Present, involving carbonate build-up, deep water turbidite deposition, consequent compression (folding and faulting), and late-event half graben-controlled deposition. Some resulting structures are indicative of tectonic inversion processes (positive and negative) which may prove to be potentially favorable in the search for structural plays in the area. 相似文献