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1.
The Umbria-Marche foreland fold-and-thrust belt in the northern Apennines of Italy provides excellent evidence to test the hypothesis of synsedimentary-structural control on thrust ramp development. This orogenic belt consists of platform and pelagic carbonates, Late Triassic to Miocene in age, whose deposition was controlled by significant synsedimentary extension. Normal faulting, mainly active from Jurassic through Late Cretaceous-Paleogene time, resulted in significant lateral thickness variability within the related stratigraphic sequences. By Late Miocene time the sedimentary cover was detached from the underlying basement and was deformed by east-verging folds and west-dipping thrusts. Two restored balanced cross sections through the southernmost part of the belt show a coincidence between the early synsedimentary normal faults and the late thrust fault ramps. These evidences suggest that synsedimentary tectonic structures, such as faults and the related lithological lateral changes, can be regarded as mechanically important controlling factors in the process of thrust ramp development during positive tectonic inversion processes.  相似文献   

2.
藏北改则新生代早期逆冲推覆构造系统   总被引:2,自引:0,他引:2  
藏北改则及邻区新生代早期发育大型逆冲推覆构造系统,由不同方向的逆冲断层、不同时代的构造岩片、不同规模的飞来峰和构造窗、不同类型的褶皱构造组成。羌塘中部发育羌中薄皮推覆构造,石炭系板岩和二叠系白云质灰岩自北向南逆冲推覆于上白垩统与古近系红层之上,形成大型逆冲岩席和弧形逆冲断层,原地系统古近纪红层下伏三叠系—侏罗系海相烃源岩。羌塘南部发育南羌塘薄皮推覆构造,导致班公—怒江蛇绿岩、三叠系—侏罗系海相地层及侏罗纪混杂岩自北向南逆冲推覆于古近纪红层与下白垩统海相沉积岩层之上,形成三条蛇绿岩片带、大量飞来峰和厚度较大的构造片岩。中新世早期火山岩层和湖相沉积呈角度不整合覆盖逆冲断层、褶皱构造和逆冲岩席,不整合面上覆火山岩年龄为23.7~19.1Ma,指示中新世早期改则及邻区基本结束了强烈逆冲推覆构造运动。估算羌中逆冲推覆构造的推覆距离约100~115km,南羌塘逆冲推覆构造的推覆距离约82~110km;新生代早期改则逆冲推覆构造系统近南北方向逆冲推覆总距离为182~225km,对应地壳缩短率为(50.3±2.7)%。  相似文献   

3.
渤海湾盆地基岩地质图及其所包含的构造运动信息   总被引:10,自引:1,他引:9  
利用油气勘探资料编制的渤海湾盆地基岩地质图 ,分析了基岩露头分布及其反映的中、新生代构造运动特征。基岩地质图显示渤海湾盆地基底岩层受印支运动和燕山运动影响发育有一系列近EW向、NNE—NE向的褶皱和逆断层等挤压构造变形。基岩露头展布表明渤海湾盆地西部、北部在侏罗纪之前的剥蚀作用明显强于东部和南部地区。基岩地层形成的区域褶皱轴向及各亚构造层之间的不整合面接触关系反映出在下—中三叠统沉积之后至下—中侏罗统沉积之前的某个“关键时刻”渤海湾地区发生了一次重要的构造变革 ,导致早期的近EW向构造被NNE—NE向构造替代。而从区域应力体制来看 ,下—中侏罗统沉积之后渤海湾地区的区域构造环境发生了重要变化 ,从中生代早期的挤压构造环境变为以裂陷作用为主的构造演化时期  相似文献   

4.
Triassic to Lower Cretaceous continental sedimentary basins occur in eastern Australia, but the tectonic and structural evolution of these basins is not fully understood. Using gridded aeromagnetic data, seismic reflection data and field observations, we conducted a structural analysis aimed at characterising major faults and deformation style in these sedimentary basins. Our results show evidence for two alternating episodes of rifting during the Triassic. An earlier episode of rifting, which took place in the Early Triassic to early Late Triassic, is inferred based on synsedimentary normal faults in the Nymboida Coal Measures and the boundary West Ipswich Fault System in the Esk Trough. This phase of rifting was followed by a contractional event that resulted in tilting, folding, and thrust faulting. Evidence of synsedimentary normal faults and bimodal volcanism indicates that another rifting phase occurred during the Late Triassic and resulted in the development of the Ipswich Basin. From the latest Late Triassic to the Early Cretaceous, the accumulation of continental sediments in the Clarence-Moreton Basin was accompanied by subsidence. We suggest that the alternating rifting episodes and contraction were ultimately controlled by plate boundary migration and switches between trench retreat and advance during the Triassic.  相似文献   

5.
The structure of the Chilean Frontal Cordillera, located over the Central Andes flat-slab subduction segment (27°–28.5°S), is characterized by a thick-skinned deformation, affecting both the pre-rift basement and the Mesozoic and Cenozoic infill of the NNE-SSW Lautaro and Lagunillas Basins, which were developed during the Pangea-Gondwana break-up. The compressive deformation show a complex interaction between Mesozoic rift structures and thrust systems, affecting a suite of Permo-Triassic (258–245 Ma) granitic blocks. We used a combination of geological mapping, new structural data, balanced and restored cross sections and geochronological data to investigate the geometry and kinematics of the Andean thick-skinned thrust systems of the region. The thrust systems include double-vergent thick-skinned thrust faults, basement-cored anticlines and minor thin-skinned thrusts and folds. The presence of Triassic and Jurassic syn-rift successions along the hanging wall and footwall of the basement thrust faults are keys to suggest that the current structural framework of the region should be associated with the shortening of previous Mesozoic half grabens. Based on this interpretation, we propose a deformation mechanism characterized by the tectonic inversion of rift-related faults and the propagation of basement ramps that fold and cut both, the early normal faults and the basement highs. New U–Pb ages obtained from synorogenic deposits (Quebrada Seca and Doña Ana formations) indicate at least three important compressive pulses. A first pulse at ∼80 Ma (Late Cretaceous), a second pulse related to the K-T phase of Andean deformation and, finally, a third pulse that occurred during the lower Miocene.  相似文献   

6.
准噶尔盆地南缘前陆冲断带位于天山北麓,在晚新生代强烈的挤压作用下,地表发育数排背斜带。由于构造变形复杂、地震反射成像质量较差,对深层地质结构争议较大,另外前新生代盆地原型对晚新生代以来的褶皱冲断带构造格局的影响也尚未探讨。霍尔果斯—玛纳斯—吐谷鲁(简称霍-玛-吐)褶皱冲断带位于准噶尔盆地南缘前陆冲断带地表第二排背斜带,利用最新采集和处理的地震反射资料,并结合地表地质露头建立深层构造模型;利用平衡地质剖面复原和构造物理模拟实验的方法探索早侏罗世盆地原型结构对现今褶皱冲断带构造格局的影响;在此基础上分析霍-玛-吐褶皱冲断带深层天然气富集规律。霍-玛-吐褶皱冲断带垂向上发育古近系—第四系逆冲推覆构造、中上侏罗统—白垩系构造楔和下侏罗统半地堑断陷结构。控制早侏罗世半地堑系统的高角度正断层在晚期挤压构造变形体系中充当逆断坡,并控制上覆构造楔和浅层逆冲推覆构造的发育。早侏罗世半地堑系统具有分段性,并通过侧向断坡进行连接,侧向断坡上覆地层发育南北向走滑调节断层。油气勘探现状表明,霍-玛-吐褶皱冲断带内部南北向走滑调节断层具有高效沟通下侏罗统烃源岩的特点,是控制天然气的富集的重要因素。以上研究表明,中西部陆内前陆冲断带前新生代古构造对于晚新生代挤压冲断构造格局和深层天然气富集规律具有重要意义。  相似文献   

7.
Abstract

The structure of la Garrotxa area within the Cadi unit (south-eastern Pyrenees) consists of a set of duplexes at different scales which repeat the different carbonatic litho-units of the Lower and Middle Eocene. These duplexes are folded by antiformal stacks structures with basement rocks in their cores. The north boundary of these antiformal stacks represents an inversion of pre-existent extensional faults which formed half-graben geometries. The basement rocks involved in the structure represent short-cuts formed in the footwall of the extensional faults. All thrusts of La Garrotxa area branch with the upper Garrotxa thrust. The more complex structure of La Garrotxa area than the adjacent areas within the Cadí unit, is due to the initial complex synsedimentary geometry of the sedimentary pile.

The Cadi unit overlies the Serrat unit with a hangingwall ramp geometry. This unit was deduced from the Serrat-1 well, drilled in 1987. The Serrat unit is made up of a Middle Eocene evaporitic sequence, with alternating shales and anhydrites and a 100 meters thick salt layer close to the top. The total thickness of this evaporitic Beuda sequence is 1 000 meters. The Beuda sequence clearly controlled the thrust geometry of the younger thrusts.  相似文献   

8.
During subduction, continental margins experience shortening along with inversion of extensional sedimentary basins. Here we explore a tectonic scenario for the inversion of two-phase extensional basin systems, where the Early-Middle Jurassic intra-arc volcano-sedimentary Oseosan Volcanic Complex was developed on top of the Late Triassic-Early Jurassic post-collisional sequences, namely the Chungnam Basin. The basin shortening was accommodated mostly by contractional faults and related folds. In the basement, regional high-angle reverse faults as well as low-angle thrusts accommodate the overall shortening, and are compatible with those preserved in the cover. This suggests that their spatial and temporal development is strongly dependent on the initial basin geometry and inherited structures.Changes in transport direction observed along the basement-sedimentary cover interface is a characteristic structural feature, reflecting sequential kinematic evolution during basin inversion. Propagation of basement faults also enhanced shortening of the overlying sedimentary cover sequences. We constrain timing of the Late Jurassic-Early Cretaceous(ca. 158-110 Ma) inversion from altered K-feldspar 40 Ar/39 Ar ages in stacked thrust sheets and K-Ar illite ages of fault gouges, along with previously reported geochronological data from the area. This "non-magmatic phase" of the Daebo Orogeny is contemporaneous with the timing of magmatic quiescence across the Korean Peninsula. We propose the role of flat/low-angle subduction of the Paleo-Pacific Plate for the development of the "Laramide-style" basement-involved orogenic event along East Asian continental margin.  相似文献   

9.
During the Neogene, the sedimentary succession changed from marine shallow water formations during the Early and Middle Miocene to lagoonal and continental formations during the Late Miocene and the Pliocene. This succession is subdivided into three sedimentary major cycles that are mainly due to compressional tectonic events. Propagating folds above a detachment within the evaporitic Triassic strata caused the formation of the tectonics. To cite this article: M. Chikhaoui, C. R. Geoscience 336 (2004).  相似文献   

10.
We constructed a geological map, a 3D model and cross-sections, carried out a structural analysis, determined the stress fields and tectonic transport vectors, restored a cross section and performed a subsidence analysis to unravel the kinematic evolution of the NE emerged portion of the Asturian Basin (NW Iberian Peninsula), where Jurassic rocks crop out. The major folds run NW-SE, normal faults exhibit three dominant orientations: NW-SE, NE-SW and E-W, and thrusts display E-W strikes. After Upper Triassic-Lower Jurassic thermal subsidence, Middle Jurassic doming occurred, accompanied by normal faulting, high heat flow and basin uplift, followed by Upper Jurassic high-rate basin subsidence. Another extensional event, possibly during Late Jurassic-Early Cretaceous, caused an increment in the normal faults displacement. A contractional event, probably of Cenozoic age, led to selective and irregularly distributed buttressing and fault reactivation as reverse or strike-slip faults, and folding and/or offset of some previous faults by new generation folds and thrusts. The Middle Jurassic event could be a precursor of the Bay of Biscay and North Atlantic opening that occurred from Late Jurassic to Early Cretaceous, whereas the Cenozoic event would be responsible for the Pyrenean and Cantabrian ranges and the partial closure of the Bay of Biscay.  相似文献   

11.
扬子板块中部南山坪背斜的形成与演化   总被引:4,自引:0,他引:4       下载免费PDF全文
南山坪背斜位于扬子板块中部,核部上震旦统含有大量沥青,是一个被破坏的古油藏。笔者通过建造分析认为震旦纪至中三叠世属于古隆起发育阶段,进一步划分出震旦纪古隆起雏形期、早古生代古隆起保持期和晚古生代—中三叠世古隆起发展期。晚三叠世至新生代属于断裂褶皱发育阶段,进一步划分出晚三叠世—中侏罗世宽缓背斜发育期、燕山运动Ⅱ幕断展背斜发育期、燕山晚期和喜玛拉雅期背斜改造期。南山坪古油藏以上震旦统灯影组白云岩为储层,以上覆下寒武统牛蹄塘组黑色碳质泥岩和石煤为烃源岩,志留纪至中三叠世古隆起聚集油气,晚三叠世至中侏罗世是油气再分配和南山坪古油藏形成时期,之后是古油藏被破坏时期。  相似文献   

12.
鲁西地块的断裂构造有两类不同分布型式:一类呈放射状分布, 由陡倾、基底右行韧性剪切带和盖层内复杂力学性质的断裂组成; 另一类呈环绕地块基底核部同心环状分布, 由3个主要盖层伸展拆离带组成, 主滑脱面分别位于古生界盖层与基底间的不整合面、石炭系与奥陶系之间的平行不整合面和中新生代断陷-沉积岩系与新生代火山-沉积物之间的断层。中生代构造变形样式可以分为3个层次:印支期褶皱-逆冲推覆构造、燕山中期NNE轴向的隔槽式箱状褶皱和燕山晚期NW、NNE向共轭正断-走滑断裂。相应地鲁西地块经历了3个成盆期, 即早-中侏罗世、早白垩世和晚白垩世, 这些中生代盆地在空间上的叠置导致了地块内部复杂的盆-山耦合关系。鲁西地块中生代有两个岩浆活动集中时期, 即早侏罗世(约190Ma)和早白垩世(132~110Ma)。综合沉积记录、岩浆活动和构造变形过程, 将鲁西地块中生代构造演化历史划分为6个阶段:晚三叠世挤压变形, 早、中侏罗世弱伸展作用, 中、晚侏罗世挤压变形与地壳增厚作用, 早白垩世大陆裂谷与地壳伸展作用, 早白垩世末期挤压变形与盆地反转事件和晚白垩世区域隆升。这些构造演化阶段和构造事件对研究和理解中生代构造体制和深部岩石圈动力学转换过程具有重要意义。   相似文献   

13.
摘要:准噶尔盆地西北缘最重要的构造特征是发育一组冲断构造。对这组冲断构造的冲断时限和冲断性质的认识不同,导致对准噶尔盆地的属性存在断陷盆地与前陆盆地之争。西北缘花岗岩及其中发育的岩墙群的精确年龄限定了研究区在314~255 Ma中处于伸展状态。西北缘侏罗系沉积范围较三叠系广,早侏罗世发育碱性玄武岩,这些都表明准噶尔盆地在侏罗纪处于伸展阶段,盆地范围不断扩大。西北缘晚三叠世地层不整合覆盖于花岗岩之上,这种现象将本区冲断构造发生的时间限定为晚二叠世至早三叠世,最晚不超过晚三叠世。在地震资料解释的西北缘剖面上,冲断构造的前缘二叠纪地层平缓且厚度稳定。西北缘二叠系发育火山岩,沉积层序具从下到上粒度由粗变细的正旋回沉积特征,沉积速率稳定,沉降曲线由陡变缓,且古地温梯度和大地热流值均较高。西北缘的圈闭类型以岩性地层等非构造圈闭为主,以构造 岩性圈闭为辅。笔者认为西北缘冲断构造的性质是在314~255 Ma伸展阶段与侏罗纪伸展阶段之间发育的一次短期反转构造,发育基底卷入的高角度冲断带,并非大规模与造山作用相关的前陆冲断带。  相似文献   

14.
自中三叠世扬子与华北板块发生碰撞—深俯冲作用以来,大别造山带南界上的襄樊—广济断裂带主要经历过两次变形事件: 1)早期变形事件发生在中三叠世末—晚三叠世初的造山带折返阶段,表现为造山带南边界上的韧性剪切带。这期北西—南东走向的剪切带向南西陡倾,发育北西—南东向的矿物拉伸线理,主要为右行走滑的运动性质,属于造山带斜向折返的侧边界走滑剪切带。造山带折返过程中将前陆褶断带北缘原先东西向褶皱改造为北西—南东走向。2)晚期变形事件发生在晚侏罗世,表现为脆性逆冲断层,使得前陆褶断带向北东逆冲在造山带南缘之上,同时在前陆上形成了一系列的逆冲断层。该断裂带的晚期逆冲活动与郯庐断裂带左行平移同时发生,代表了滨太平洋构造活动的开始。  相似文献   

15.
笔者从冲断活动的产物———各种成因扇体(冲积扇、水下扇、扇三角洲)出发,由160口单井剖面、15条联井剖面、8个层位平面渐次展开了准噶尔西北缘前陆冲断带三叠—侏罗纪逆冲断裂活动的沉积响应研究。三叠纪扇体在乌尔禾—夏子街地区发育叠置程度最好,T1b到T3b,其由盆内向盆缘老山方向退缩迁移明显,并具T1b到T2k1由盆缘向盆内、T2k2到T3b由盆内向盆缘迁移的2个进退波动变化。侏罗纪扇体在八道湾组最为发育,总体叠置关系较差,J1b到J2t,均呈由盆内向盆缘老山退缩沉积的退覆式迁移特征。三叠纪到侏罗纪,总体为由强到弱的退覆式冲断活动及扇体迁移模式,即随主要同生控扇断裂分布由盆缘向老山方向退缩迁移,冲断活动强度由盆缘向盆地方向逐渐减弱直至停息;相应地,各期扇体平面上分布规模渐小,总体呈由盆内向盆缘老山退缩迁移的沉积响应,两者耦合性良好。各类扇体的沉积分布受不同时期同生断裂活动的严格控制,其时空叠置及迁移规律的差异是红山嘴—车排子、克拉玛依—百口泉及乌尔禾—夏子街各构造带冲断作用地域性及作用强度差异性的沉积响应。进而引入“活动性指数”的概念与方法,对前陆冲断带同生断裂的冲断活动强度进行了定量化统计分析,并根据冲断推覆事件的地层、沉积标识划分出T1b-T3b、J1b-J2x、J2t三套构造层序,识别出三叠—侏罗纪的3个逆冲推覆幕、6次逆冲推覆事件。  相似文献   

16.
柴达木盆地狮子沟-油砂山构造带变形特征及成因模拟   总被引:3,自引:0,他引:3  
通过地震剖面解释、平衡剖面编制、构造物理模拟等综合研究,认为狮子沟-油砂山构造带具有垂向分层、走向分段变形特征.垂向上以T3地震反射层为界划分为深、浅两个构造层,深层变形样式为正断层组成的地堑、半地堑、反转半地堑组合,浅层变形样式为滑脱断层、冲起背斜构造组合.走向上可划分为狮子沟、油砂山、大乌斯三个构造段,其变形样式分...  相似文献   

17.
A 100 km long balanced structural transect is presented for the Patagonian Andes at 50° S Latitude. The area studied is characterized by a fold belt in the eastern Andean foothills and basement-involved thrusts in a western-basement thrust zone. The basement thrust zone exposes pre-Jurassic, polydeformed sedimentary and layered metamorphic rocks emplaced over Lower Cretaceous rocks above an E-vergent thrust located at the western end of the fold belt.

The fold belt is developed in a 3 km thick deformed Cretaceous–Paleogene sedimentary cover with few basement outcrops and scarce calc-alkaline magmatism. Cover structures related to shallow décollements have a N-S to NW-SE strike, with fold wavelengths from 1100 to 370 m in the east to 20 to 40 m in the west. However, long-wavelength basement-involved structures related to deeper décollements have a dominant N-S to NE-SW trend along the eastern and western parts of the fold belt. Field evidence showing different degrees of inversion of N-S–trending normal faults suggests that the orientation of the Cenozoic compressive basement structures was inherited partially from the original geometry of Mesozoic normal faults.

The deformation propagated toward the foreland in at least two events of deformation. The effects of Paleogene (Eocene?) compressive episode are observed in the western fold belt and a Neogene (Late Miocene) compressive episode is present in the eastern fold belt. Basement-involved structures typically refold older cover structures, producing a mixed thick and thin-skinned structural style. By retrodeforming a regional balanced cross section in the fold belt, a minimum late Miocene shortening of 35 km (26%) was calculated.  相似文献   

18.
玉东-玛东构造带位于塔里木盆地,是在中寒武统膏盐层上滑脱的大规模褶皱冲断带,内部发育多种断层相关褶皱。目前对此构造带的研究,多关注了构造带的局部以及断裂变形。本文根据断层相关褶皱理论,利用地震资料,分析了玉东-玛东构造带内构造样式上的差异性,并通过二维构造正演模拟,建立了典型构造样式的运动学模式。认为研究区内玉东、玛东、塘北3个分区,具有不同的构造样式。玉东地区主要发育和铲式逆断层相关的断弯褶皱,玛东、塘北地区则发育断层突破的滑脱褶皱,突破断层在玛东地区为铲式断裂,而在塘北地区为坪-坡-坪式断裂。根据上奥陶统变形特征及其顶面不整合面之上的地层年代,认为玉东-玛东构造带的变形始于晚奥陶世,主要断裂及其相关褶皱形成于晚奥陶世末期。玉东地区在晚奥陶世早期,形成基底-盖层的低幅褶皱,在晚奥陶世末,形成铲式断裂及断弯褶皱;玛东和塘北地区变形发生在上奥陶统沉积之后,经历了滑脱褶皱和断层突破阶段。通过对比分析认为,断层相关褶皱样式的差异,与膏盐层岩性、厚度,上奥陶统岩性、厚度及构造转换作用有关。本研究有助于完善对塔里木盆地早古生代末期构造变形及演化的认识。  相似文献   

19.
The Somogy hills are located in the Pannonian Basin, south of Lake Balaton, Hungary, above several important tectonic zones. Analysis of industrial seismic lines shows that the pre-Late Miocene substratum is deformed by several thrust faults and a transpressive flower structure. Basement is composed of slices of various Palaeo-Mesozoic rocks, overlain by sometimes preserved Paleogene, thick Early Miocene deposits. Middle Miocene, partly overlying a post-thrusting unconformity, partly affected by the thrusts, is also present. Late Miocene thick basin-fill forms onlapping strata above a gentle paleo-topography, and it is also folded into broad anticlines and synclines. These folds are thought to be born of blind fault reactivation of older thrusts. Topography follows the reactivated fold pattern, especially in the central-western part of the study area.

The map pattern of basement structures shows an eastern area, where NE–SW striking thrusts, folds and steep normal faults dominate, and a western one, where E–W striking thrusts and folds dominate. Folds in Late Neogene are also parallel to these directions. A NE–SW striking linear normal fault and associated N–S faults cut the highest reflectors. The NE–SW fault is probably a left-lateral master fault acting during–after Late Miocene. Gravity anomaly and Pleistocene surface uplift maps show a very good correlation to the mapped structures. All these observations suggest that the main Early Miocene shortening was renewed during the Middle and Late Miocene, and may still persist.

Two types of deformational pattern may explain the structural and topographic features. A NW–SE shortening creates right-lateral slip along E–W faults, and overthrusts on NE–SW striking ones. Another, NNE–SSW shortening creates thrusting and uplift along E–W striking faults and transtensive left-lateral slip along NE–SW striking ones. Traces of both deformation patterns can be found in Quaternary exposures and they seem to be consistent with the present day stress orientations of the Pannonian Basin, too. The alternation of stress fields and multiple reactivation of the older fault sets is thought to be caused by the northwards translation and counter-clockwise rotation of Adria and the continental extrusion generated by this convergence.  相似文献   


20.
常德-安仁断裂是湖南东部一条NW向大断裂,关于其地质特征、活动历史及构造性质等尚缺乏系统研究.基于区域地质调查和基础地质研究资料,总结了常德-安仁断裂的总体特征,重塑了断裂的活动历史,探讨了断裂的构造性质和变形机制.主要认识如下:常德-安仁断裂走向NW330°,为一基底隐伏断裂,地质上表现为一NW向岩浆隆起带.该断裂为贯穿中、下地壳并切入岩石圈地幔的深大断裂,断裂倾向NE,倾角约54°.断裂具有长期活动历史:新元古代冷家溪期作为转换断层具走滑活动;冷家溪末期武陵(晋宁)运动中在区域S-N向挤压下右行走滑;板溪期早期和南华纪早期均具伸展活动并控制沉积相带的展布;加里东运动中在区域S-N向挤压下右行走滑;中三叠世晚期印支运动中在区域NW-NWW向挤压下左行走滑兼逆冲;晚三叠世-早侏罗世在区域S-N向挤压下右行走滑;中侏罗世晚期早燕山运动中在区域NWW向挤压下左行走滑;白垩纪-古近纪产生伸展活动.常德-安仁断裂在冷家溪期可能为一横切扬子陆块东南缘弧后盆地、岛弧和华南洋的转换断层.印支运动中断裂带因深部逆冲活动而构造隆升.该断裂具隐伏特征的原因可能与冷家溪期-南华纪同沉积活动、震旦系底部滑脱层发育、多条NE-NNE向大断裂的截切以及断裂沿线花岗岩体和断陷盆地的发育等有关.   相似文献   

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