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1.
《Geodinamica Acta》1998,11(5):233-247
In New Zealand, the Marlborough strike-slip faults link the Hikurangi subduction zone to the Alpine fault collision zone. Stratigraphic and structural analysis in the Marlborough region constrain the inception of the current strike-slip tectonics.Six major Neogene basins are investigated. Their infill is composed of marine and freshwater sediments up to 3 km thick; they are characterised by coarse facies derived from the basins bounding relief, high sedimentation rates and asymmetric geometries. Proposed factors that controlled the basins' generation are the initial geometry of the strike-slip faults and the progressive strike-slip motion. Two groups of basins are presented: the early Miocene (23 My) basins were generated under wrench tectonics above releasing-jogs between basement faults. The late Miocene (11 My) basins were initiated by halfgrabens tilted along straighter faults during a transtensive stage. Development of faults during Cretaceous to Oligocene times facilitated the following propagation of wrench tectonics. The Pliocene (5 My) to current increasing convergence has shortened the basins and distorted the Miocene array of faults. This study indicates that the Marlborough Fault System is an old feature that connected part of the Hikurangi margin to the Alpine fault since the subduction and collision initiation.  相似文献   

2.
Abstract

In New Zealand, the Marlborough strike-slip faults link the Hikurangi subduction zone to the Alpine fault collision zone. Stratigraphic and structural analysis in the Marlborough region constrain the inception of the current strike-slip tectonics.

Six major Neogene basins are investigated. Their infill is composed of marine and freshwater sediments up to 3 km thick; they are characterised by coarse facies derived from the basins bounding relief, high sedimentation rates and asymmetric geometries. Proposed factors that controlled the basins generation are the initial geometry of the strike-slip faults and the progressive strike-slip motion. Two groups of basins are presented: the early Miocene (23 My) basins were generated under wrench tectonics above releasing-jogs between basement faults. The late Miocene (11 My) basins were initiated by halfgrabens tilted along straighter faults during a transtensive stage. Development of faults during Cretaceous to Oligocene times facilitated the following propagation of wrench tectonics. The Pliocene (5 My) to current increasing convergence has shortened the basins and distorted the Miocene array of faults. This study indicates that the Marlborough Fault System is an old feature that connected part of the Hikurangi margin to the Alpine fault since the subduction and collision initiation. © Elsevier, Paris  相似文献   

3.
《Geodinamica Acta》2003,16(2-6):131-147
Combining fieldwork and surface data, we have reconstructed the Cenozoic structural and tectonic evolution of the Northern Bresse. Analysis of drainage network geometry allowed to detect three major fault zones trending NE–SW, E–W and NW–SE, and smooth folds with NNE trending axes, all corroborated with shallow well data in the graben and fieldwork on edges. Cenozoic paleostress succession was determined through fault slip and calcite twin inversions, taking into account data of relative chronology. A N–S major compression, attributed to the Pyrenean orogenesis, has activated strike-slip faults trending NNE along the western edge and NE–SW in the graben. After a transitional minor E–W trending extension, the Oligocene WNW extension has structured the graben by a collapse along NNE to NE–SW normal faults. A local NNW extension closes this phase. The Alpine collision has led to an ENE compression at Early Miocene. The following WNW trending major compression has generated shallow deformation in Bresse, but no deformation along the western edge. The calculation of potential reactivation of pre-existing faults enables to propose a structural sketch map for this event, with a NE–SW trending transfer fault zone, inactivity of the NNE edge faults, and possibly large wavelength folding, which could explain the deposit agency and repartition of Miocene to Quaternary deformation.  相似文献   

4.
文章以青藏高原东缘龙门山活动构造的地貌标志为切入点,在汶川-茂汶断裂、北川断裂、彭灌断裂和大邑断裂等主干活动断裂的关键部位,对断错山脊、洪积扇、河流阶地、边坡脊、断层陡坎、河道错断、冲沟侧缘壁位错、拉分盆地、断层偏转、砾石定向带、坡中槽、弃沟和断塞塘等活动构造地貌和断裂带开展了详细的野外地质填图和地貌测量,利用精确的地貌测量数据和测年数据,定量计算了龙门山主干断裂的逆冲速率和走滑速率,结果表明在晚新生代时期龙门山构造带仅具有微弱的构造缩短作用,其中逆冲速率的速度值小于1.1mm/a,走滑速率的速度值小于1.46mm/a,表明走滑分量与逆冲分量的比率介于6 ∶ 1~1.3 ∶ 1之间,以右行走滑作用为主。在此基础上,对各主干活动断裂的逆冲速率和走滑速率进行了定量的对比研究,结果表明自北西向南东4条主干断裂的最大逆冲分量滑动速率具有变小的趋势,而走滑分量的滑动速率则具有逐渐变大的趋势,显示了从龙门山的后山带至前山带主干断裂的走滑作用越来越强。由此推测现今的龙门山及其前缘盆地不完全是由于构造缩短作用形成的,而主要是走滑作用和剥蚀卸载作用的产物。另外,根据沉积、构造、盆地充填体的几何形态、地貌、古地磁等标定和对比了龙门山在中生代和新生代的走滑方向,表明龙门山构造带在中生代与新生代之交走滑方向发生了反转,即由中生代时期的左行变为新生代时期的右行。  相似文献   

5.
龙门山断裂带走滑方向的反转及其沉积与地貌标志   总被引:11,自引:0,他引:11  
根据龙门山前陆盆地西缘沉降中心、冲积扇侧向迁移、活动构造地貌和古地磁等标志及龙门山在中生代以来的走滑作用和走滑方向的标定研究,结果表明:龙门山断裂带具有走滑性质,走滑方向曾发生过反转,在反转之前以左行走滑作用为特征,在反转之后以右行走滑作用为特征。根据地层记录和古地磁证据,认为龙门山走滑方向反转的时间应介于43 M a~3.6 M a之间,即由中生代至早新生代时期的左行走滑作用反转为晚新生代时期的右行走滑作用。然对龙门山断裂带走滑方向反转的成因初步分析认为晚新生代龙门山右行走滑作用是印-亚碰撞后构造作用的产物,晚三叠世至早新生代左行走滑作用是青藏高原自晚三叠世以来大陆碰撞作用导致松潘-甘孜褶皱带北东-南西向缩短的产物。  相似文献   

6.
This paper presents a geological–structural study of some Neogene hinterland basins of the Northern Apennines, located on the Tyrrhenian side of the chain. These basins developed on the already delineated thrust-fold belt from middle–late Tortonian times. Their evolution has been commonly referred to an extensional tectonic regime, related to the opening of the Tyrrhenian Sea. New data have allowed us to hypothesize a different tectonic evolution for the chain, where compressive tectonics plays a major role both in the external and in the hinterland area. In this frame, the hinterland area located west of a major outcropping crustal thrust (Mid-Tuscany Metamorphic Ridge) has been the target of a geological–structural investigation. The field mapping and structural analysis has been focused on the syntectonic sediments of the Radicondoli–Volterra basin as well as on adjoining minor basins. These basins commonly display a synclinal structure and are generally located in between basement culminations, probably corresponding to thrust anticlines. Sediments of the hinterland basins have been affected by compressive deformation and regional unconformities separate stratigraphic units due to the activity of basement thrusts. In the study area, normal faulting either accommodates the thrusting processes or post-dates compressive deformation. A chronology of faulting and a six-stage evolution of this area are presented, providing further insights for the Neogene tectonic evolution of the Northern Apennines. Copyright © 1998 John Wiley & Sons, Ltd.  相似文献   

7.
中国西南部红河断裂带的活动演化历史长期以来备受国内外学者的关注,该断裂从陆地向海域延伸进入莺歌海盆地,并对莺歌海盆地的形成和演化起重要的控制作用。目前,红河断裂带经历早期的左旋走滑运动和后期的右旋走滑运动已经得到公认,但对于其精细的构造演化历史及其左旋走滑向右旋走滑运动转换的时间还未能达成共识。本文利用构造控制沉积、沉积反映构造的思想,通过对莺歌海盆地三维地震资料的构造解析,从T27界面上下地层厚度存在"跷跷板"式的变化、沉积中心的迁移、沉积速率的变化、陆架-陆坡坡折带的出现、微小断裂的特征以及底辟构造等方面的研究,确定莺歌海盆地红河断裂带的左旋走滑运动停止于T40(10.5Ma);T40~T30(10.5~5.5Ma)是构造变形的平静期;T30~T27(5.5~2.4 Ma)为左旋走滑运动向右旋走滑运动转换时期;T27(2.4 Ma)以后右旋走滑活动开始,并控制坡折带(包括莺歌海盆地和琼东南盆地)和底辟构造等的形成;T20(1.9 Ma)以来,右旋走滑活动逐渐减弱。  相似文献   

8.
9.
In the interior of the Iberian Peninsula, the main geomorphic features, mountain ranges and basins, seems to be arranged in several directions whose origin can be related to the N–S plate convergence which occurred along the Cantabro–Pyrenean border during the Eocene–Lower Miocene time span. The Iberian Variscan basement accommodated part of this plate convergence in three E–W trending crustal folds as well as in the reactivation of two left-lateral NNE–SSW strike-slip belts. The rest of the convergence was assumed through the inversion of the Iberian Mesozoic Rift to form the Iberian Chain. This inversion gave rise to a process of oblique crustal shortening involving the development of two right lateral NW–SE shear zones. Crustal folds, strike-slip corridors and one inverted rift compose a tectonic mechanism of pure shear in which the shortening is solved vertically by the development of mountain ranges and related sedimentary basins. This model can be expanded to NW Africa, up to the Atlasic System, where N–S plate convergence seems also to be accommodated in several basement uplifts, Anti-Atlas and Meseta, and through the inversion of two Mesozoic rifts, High and Middle Atlas. In this tectonic situation, the microcontinent Iberia used to be firmly attached to Africa during most part of the Tertiary, in such a way that N–S compressive stresses could be transmitted from the collision of the Pyrenean boundary. This tectonic scenario implies that most part of the Tertiary Eurasia–Africa convergence was not accommodated along the Iberia–Africa interface, but in the Pyrenean plateboundary. A broad zone of distributed deformation resulted from the transmission of compressive stresses from the collision at the Pyrenean border. This distributed, intraplate deformation, can be easily related to the topographic pattern of the Africa–Eurasia interface at the longitude of the Iberian Peninsula.Shortening in the Rif–Betics external zones – and their related topographic features – must be conversely related to more “local” driven mechanisms, the westward displacement of the “exotic” Alboran domain, other than N–S convergence. The remaining NNW–SSE to NW–SE, latest Miocene up to Present convergence is also being accommodated in this zone straddling Iberia and Morocco, at the same time as a new ill-defined plate boundary that is being developed between Europe and Africa.  相似文献   

10.
《Geodinamica Acta》2003,16(2-6):99-117
The Bielsa thrust sheet is a south-verging unit of the Axial zone in the central Pyrenees. The Bielsa thrust sheet consists predominantly of a Variscan granite unconformably overlain by a thin cover of Triassic and Cretaceous deposits. During the Eocene–Oligocene, Pyrenean compression, displacement of the Bielsa thrust sheet generated a large-scale south-verging monocline. Low temperature deformation of the Bielsa thrust sheet resulted in the development of: (1) E–W trending, asymmetric folds in the Triassic cover with amplitudes up to 1.5 km; these folds of the cover are related with normal and reverse faults in the granite and with rigid-body block rotations. (2) Pervasive fracturing within the Bielsa granite is also attributed to Pyrenean deformation and is consistent with a NNE to ENE shortening direction; two main, conjugate fault systems are associated with this direction of shortening, as is a subvertical strike-slip system with shallow-plunging slickenside lineations and a moderately dipping fault system with reverse movement; and (3) in addition, we recognise strike-slip and reverse shear bands, associated with sericitisation and brittle deformation of quartz and feldspar in the granite, that enclose Triassic rocks. Basement deformation within the Bielsa thrust sheet can be related to movement of faults developed to accommodate internal deformation of the hanging wall. Several models are proposed to account for this deformation during the southward displacement of the thrust.  相似文献   

11.
《Sedimentary Geology》2005,173(1-4):53-89
Three related basins in southern Turkey, the Ecemiş Basin, the Karsanti Basin and the Aktoprak Basin, document the Neogene-Recent regional exhumation and surface uplift history of the Central Taurus Mountains. The regional tectonic framework was established by a Late Eocene phase of compressional deformation that ended Tethys-related marine deposition. During the Oligocene–Early Miocene non-marine sedimentation was dominantly from braided rivers flowing from the nascent Taurus Mountains and from the Niğde metamorphic massif further north. During this period erosion more or less kept pace with exhumation and the topography remained subdued, allowing a marine incursion (probably eustatically controlled) into the Karsanti Basin in the east during Early Oligocene time. Regional exhumation was possibly controlled by thermal uplift of an actively extending area located behind the subducting S-Neotethys in the Eastern Mediterranean Sea. During exhumation, largely ophiolitic rocks were eroded, revealing the deformed Mesozoic Tauride carbonate platform beneath. The area was affected by a short-lived pulse of compressional deformation/transpression, probably in Mid-Miocene time, but extensional exhumation then resumed, as indicated by the presence of metamorphic-derived clasts from the adjacent Niğde Massif. Late Miocene deposition was dominated by large inward-draining lakes, consistent with regional evidence of a humid climate during this time. Strong surface uplift took place during Plio-Quaternary time. Drainage to the Mediterranean became established, allowing river valleys to incise deeply into the flanks of the Taurus Mountains. Palaeo-valleys were successively infilled with coarse alluvial sediments. This deposition was influenced by NE–SW trending extensional faults. In addition, the sedimentary evolution of the area was strongly influenced by the NNE–SSW trending Ecemiş Fault Zone, which has experienced ca. 60 km of left-lateral strike-slip since the Late Eocene. An important pulse of normal faulting/transtension in latest Miocene–early Pliocene time generated large fault scarps. These acted as sources for large Plio-Quaternary alluvial fans, which prograded across active strike-slip faults. The morphology of these fans was influenced by a combination of Quaternary climatic change, axial-fluvial downcutting and active strike-slip tectonics. In general, the Plio-Quaternary regional uplift of the Taurus Mountains may relate to underplating of material derived from the African plate during progressive collision with the Anatolian (Eurasian) plate in the vicinity of the easternmost Mediterranean Sea.  相似文献   

12.
走滑断层作用的相关构造   总被引:32,自引:3,他引:29  
走滑断层的形成可以用纯剪和单剪这两种基力学机制和它们之间的过渡类型-压剪和张剪加以解释,其应力分布的局域性导致了形变特性的差异性。其相关构造类型,包括褶皱断层,断层,走滑盆地,走滑旋转构造,花状构造与走滑双重构造,等是走滑断层的主要研究对象和内容。  相似文献   

13.
The late Eocene to Neogene tectonic evolution of the Dinarides is characterised by shortening and orogen-parallel wrenching superposed on the late Cretaceous and Eocene double-vergent orogenic system. The Central Dinarides exposes NW-trending tectonic units, which were transported towards the Adria/Apulian microcontinent during late Cretaceous–Palaeogene times. These units were also affected by subsequent processes of late Palaeogene to Neogene shortening, Neogene extension and subsidence of intramontane sedimentary basins and Pliocene–Quaternary surface uplift and denudation. The intramontane basins likely relate to formation of the Pannonian basin. Major dextral SE-trending strike-slip faults are mostly parallel to boundaries of major tectonic units and suggest dextral orogen-parallel wrenching of the whole Central Dinarides during the Neogene indentation of the Apulian microplate into the Alps and back-arc type extension in the Pannonian basin. These fault systems have been evaluated with the standard palaeostress techniques. We report four palaeostress tensor groups, which are tentatively ordered in a succession from oldest to youngest: (1) Palaeostress tensor group 1 (D1) of likely late Eocene age indicates E–W shortening accommodated by reverse and strike-slip faults. (2) Palaeostress tensor group 2 (D2) comprises N/NW-trending dextral and W/WSW-trending sinistral strike-slip faults, as well as WNW-striking reverse faults. These indicate NE–SW contraction and subordinate NW–SE extension related to Oligocene to early Miocene shortening of the Dinaric orogenic wedge. (3) Palaeostress tensor group 3a (D3a) comprises mainly NW-trending normal faults, which indicate early/middle Miocene NE–SW extension related to syn-rift extension in the Pannonian basin. The subsequent palaeostress tensor group 3b (D3b) includes NE-trending, SE-dipping normal faults indicating NW–SE extension, which is likely related to further extension in the Pannonian basin. (4) Palaeostress tensor group 4 (D4) is characterised by mainly NW-trending dextral and NE-trending sinistral strike-slip faults. Together, with some E-trending reverse faults, they indicate roughly N–S shortening and dextral wrenching during late Miocene to Quaternary. This is partly consistent with the present-day kinematics, with motion of the Adriatic microplate constrained by GPS data and earthquake focal mechanisms. The north–north-westward motion and counterclockwise rotation of the Adriatic microplate significantly contribute the shortening and present-day wrenching in the Central Dinarides.  相似文献   

14.
The Main Recent Fault of the Zagros Orogen is an active major dextral strike-slip fault along the Zagros collision zone, generated by oblique continent–continent collision of the Arabian plate with Iranian micro-continent. Two different fault styles are observed along the Piranshahr fault segment of the Main Recent Fault in NW Iran. The first style is a SW-dipping oblique reverse fault with dextral strike-slip displacement and the second style consists of cross-cutting NE-dipping, oblique normal fault dipping to the NE with the same dextral strike-slip displacement. A fault propagation anticline is generated SW of the oblique reverse fault. An active pull-apart basin has been produced to the NE of the Piranshahr oblique normal fault and is associated with other sub-parallel NE-dipping normal faults cutting the reverse oblique fault. Another cross-cutting set of NE–SW trending normal faults are also exist in the pull-apart area. We conclude that the NE verging major dextral oblique reverse fault initiated as a SW verging thrust system due to dextral transpression tectonic of the Zagros collision zone and later it has been overprinted by the NE-dipping oblique normal fault producing dextral strike-slip displacement reflecting progressive change of transpression into transtension in the collision zone. The active Piranshahr pull-apart basin has been generated due to a releasing damage zone along the NW segment of the Main Recent Fault in this area at an overlap of Piranshahr oblique normal fault segment of the Main Recent Fault and the Serow fault, the continuation of the Main Recent Fault to the N.  相似文献   

15.
The NW-SE trending Sanandaj-Sirjan Zone (SSZ) is the internal part of the Zagros continental collision zone, which mainly consists of metamorphic rocks deformed in a dextral transpressional zone. This dextral transpression is attributed to brittle deformation related to late Cenozoic Arabia-Eurasia oblique continental collision. Major NW-trending faults, including the Dalan, Garmdareh, Yasechah, Sheida, and Ben faults, are reverse faults with a dextral strike-slip component. These faults were displaced by NW-trending synthetic and NE-trending antithetic faults. There are also E-trending thrusts and N-trending normal faults developing in directions that are, respectively, almost normal and parallel to the major shortening direction. The NW-trending Ben, Yasechah, and Sheida faults are NE-dipping faults, and the Dalan and Garmdareh faults are SW-dipping faults. These faults indicate the presence of a transpressive flower structure zone that probably led to the exhumation of Jurassic high-grade metamorphic rocks, such as eclogite, in the central part of the study area.  相似文献   

16.
辽东湾坳陷新生代构造改造作用及演化   总被引:1,自引:0,他引:1       下载免费PDF全文
利用大量的渤海油气勘探资料与成果对辽东湾坳陷构造演化特点综合分析,揭示出辽东湾坳陷新生代构造改造作用主要表现在:断裂作用、地层抬升剥蚀及褶皱作用,对辽东湾坳陷构造演化过程具有重要的影响。其西部地区现今构造特征主要受前期伸展断层控制,构造改造作用较弱;而东部地区构造改造作用强烈,辽东凸起是在后期构造改造作用下形成的,分隔现今的辽中凹陷与辽东凹陷。郯庐断裂带辽东湾段新生代早期活动特征不明显,始新世末-渐新世主要以伸展作用叠加右旋走滑作用为主;渐新世末-新近纪晚期以右旋走滑作用为主,断裂带活动不控制辽东湾东部地区的沉积。辽东湾坳陷新生代的演化整体可划分为断陷期(孔店组沉积期-沙河街组三段沉积期)、断坳改造期(沙河街组二段沉积期-东营组沉积期)、走滑改造期(馆陶组沉积期至今)3个演化阶段。现今辽东湾坳陷构造格局与沙河街组三段沉积前古构造格局的差异性,对该区海域油气勘探具有重要意义。  相似文献   

17.
珠江口盆地的成盆机制和构造演化过程探讨是该地区烃源岩研究中不可缺少的环节,也是大家广泛关注的焦点问题。本文以阳江东凹为例,通过整体与局部相结合的分析方法,从整体上确定了研究区走滑断裂的发育特征和展布框架,明确了区域构造运动与走滑断裂的成因联系;并将整体划分成局部,聚焦于阳江东凹古近纪盆地构造演化阶段逐步分解与精细检验,对珠江口盆地的成盆机制、发育过程和演化模式进行分阶段解剖和分析。结果表明,研究区的构造演化过程分为三个阶段:文三段沉积期NW-SE向伸展,文二段沉积期南北向区域拉张作用下NE走向断裂右行右阶走滑拉分和文一段-恩平组沉积期NWW向走滑断裂左行左阶拉分。由于三个阶段受到不同的区域构造运动影响,各阶段盆地的打开方式和断裂的分布特征具有一定差异。同时,不同时期的构造演化过程与同时期区域构造应力场的转变一一对应,控制了沉积-沉降中心的分布,据此本文提出珠江口盆地的裂解模式是多期走滑构造控制的"叠合型"拉分盆地的新认识,研究区整体表现为三期构造叠合型盆地,盆地的构造叠合机制与洼陷的生烃排烃具有一定的相关性。  相似文献   

18.
郯庐断裂带的形成与演化:综述   总被引:81,自引:0,他引:81  
万天丰  朱鸿 《现代地质》1996,10(2):159-168
从历史的与整体的观点出发,综合了地质、地貌、地球化学与地球物理的资料,系统地研究了郯庐断裂带各阶段的形态学、运动学以及动力学机制。认为此断裂带开始形成于中、晚三叠世,其长度小于1500km,切割深度小于15~20km,此时最大左行走滑断距为430km左右。侏罗纪(208~135Ma)与中始新世-渐新世(52~23.3Ma),此断裂带表现为逆断层活动,断层面受挤压较紧闭。白垩纪-早始新世(135~52Ma),郯庐断裂呈现为略带右行走滑的正断层(走滑断距不超过100km),郯庐断裂带与其北部切割深度约为30~40km。中新世-更新世(23.3~0.73Ma)断裂带表现为带有左行走滑的正断层,走滑断距约50km,断裂带切割深度在50~80km之间。中更新世(0.73Ma以来)断裂带又变成略带右行走滑的逆断层,走滑断距不足100m。由于断裂带形成以来的剥蚀深度不大,地表的断层岩都是碎裂岩与断层泥。沿此断裂带在早白垩世构成了中国东部重要的内生金属成矿带。  相似文献   

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G. Musumeci 《Geodinamica Acta》2013,26(1-2):119-133
Abstract

The Monte Grighini Complex (Central-Western Sardinia) is a NW-SE trending metamorphic complex of Hereynian age made up of a medium grade Lower tectonic unit with mylonitie granitoids and a low grade Upper tectonic unit exposed in the westernmost and southernmost portions of this complex. The Lower Unit shows a prograde metamor phism from garnet to sillimanite zone and the transition from MP/MT to LP/HT metamorphism. The metamorphic climax was reached at the end of the main deformative phase 1)2 (600° C. 6 kbar). After the main tectonic and metamorphic phase. the Lower Unit was affected by a wide NW-SE trending ductile dextral wrench shear zone. Intrusive rocks emplaced within the shear zone yielded radiometric ages of 305-300 Ma. Shear deformation leads to low temperature C-S mylonites and retrograde phyllonitic rocks with subhorizontal NW-SE trending stretching lineations. Kinematic analysis of the shear zone points to a dextral sense of shear with an amount of ductile displacement of about 7 km. Later low angle N-S and E-W trending normal faults are associated with cataclastic zones separating the Lower Unit from the Upper one. These faults originated during a later evolutionary stage of the shear zone. This shows a progressive change of deformation regime from duetile wrenching to brittle normal faulting. The Monte Grighini Complex is a good example of ductile wrench tectonics. followed by uplift and extension in the Paleozoic basement of Sardinia.  相似文献   

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