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1.
台湾海峡地区新生代的构造演化   总被引:9,自引:1,他引:9  
根据采集反射剖面,结合区域地质资料,分析了晋江凹陷、九龙江凹陷、新竹凹陷、台中凹陷和台湾凹陷为半地堑结构。新竹凹陷和台中凹陷下拗,演变为前陆盆地。晋江凹陷和九龙江凹陷因岩石圈上隆,其沉积较薄。这种模式决定了在台湾海峡地区,西部的生油气层为下第三系,而东部的生油气层为下第三系和上第三系。  相似文献   

2.
The sea floor topography around Taiwan is characterized by the asymmetry of its shallow and flat shelves to the west and markedly deep troughs and basins to the south and east. Tectonics and sedimentation are major controls in forming the submarine physiographic features around Taiwan. Three Pliocene-Quaternary shelves are distributed north and west of Taiwan: East China Sea Shelf (passive margin shelf), the Taiwan Strait Shelf (foreland shelf), and Kaoping Shelf (island shelf) from north to south parallel to the strike of Taiwan orogen. Off northeastern Taiwan major morpho/tectonic features associated with plate subduction include E-W trending Ryukyu Trench, Yaeyama accretionary wedge, forearc basins, the Ryukyu Arcs, and the backarc basin of southern Okinawa Trough. Off eastern Taiwan lies the deep Huatung Basin on the Philippine Sea plate with a relatively flat floor, although several large submarine canyons are eroding and crossing the basin floor. Off southeastern Taiwan, the forearc region of the Luzon Arc has been deformed into five alternating N-S trending ridges and troughs during initial arc-continent collision. Among them, the submarine Hengchun Ridge is the seaward continuation of the Hengchun peninsula in southern Taiwan. Off southwestern Taiwan, the broad Kaoping Slope is the major submarine topographic feature with several noticeable submarine canyons. The Penghu Canyon separates this slope from the South China Sea Slope to the west and merges southwards into the Manila Trench in the northern South China Sea. Although most of sea floors of the Taiwan Strait are shallower than 60?m in water depth, there are three noticeable bathymetric lows and two highs in the Taiwan Strait. There exists a close relationship between hydrography and topography in the Taiwan Strait. The circulation of currents in the Taiwan Strait is strongly influenced by seasonal monsoon and semidiurnal tides. The Penghu Channel-Yunchang Ridge can be considered a modern tidal depositional system. The Taiwan Strait shelf has two phases of development. The early phase of the rift margin has developed during Paleoocene-Miocene and it has evolved to the foreland basin in Pliocene-Quaternary time. The present shelf morphology results mainly from combined effects of foreland subsidence and modern sedimentation overprinting that of the Late Pleistocene glaciation about 15,000 years ago.  相似文献   

3.
The sea floor topography around Taiwan is characterized by the asymmetry of its shallow and flat shelves to the west and markedly deep troughs and basins to the south and east. Tectonics and sedimentation are major controls in forming the submarine physiographic features around Taiwan. Three Pliocene-Quaternary shelves are distributed north and west of Taiwan: East China Sea Shelf (passive margin shelf), the Taiwan Strait Shelf (foreland shelf), and Kaoping Shelf (island shelf) from north to south parallel to the strike of Taiwan orogen. Off northeastern Taiwan major morpho/tectonic features associated with plate subduction include E-W trending Ryukyu Trench, Yaeyama accretionary wedge, forearc basins, the Ryukyu Arcs, and the backarc basin of southern Okinawa Trough. Off eastern Taiwan lies the deep Huatung Basin on the Philippine Sea plate with a relatively flat floor, although several large submarine canyons are eroding and crossing the basin floor. Off southeastern Taiwan, the forearc region of the Luzon Arc has been deformed into five alternating N-S trending ridges and troughs during initial arc-continent collision. Among them, the submarine Hengchun Ridge is the seaward continuation of the Hengchun peninsula in southern Taiwan. Off southwestern Taiwan, the broad Kaoping Slope is the major submarine topographic feature with several noticeable submarine canyons. The Penghu Canyon separates this slope from the South China Sea Slope to the west and merges southwards into the Manila Trench in the northern South China Sea. Although most of sea floors of the Taiwan Strait are shallower than 60 m in water depth, there are three noticeable bathymetric lows and two highs in the Taiwan Strait. There exists a close relationship between hydrography and topography in the Taiwan Strait. The circulation of currents in the Taiwan Strait is strongly influenced by seasonal monsoon and semidiurnal tides. The Penghu Channel-Yunchang Ridge can be considered a modern tidal depositional system. The Taiwan Strait shelf has two phases of development. The early phase of the rift margin has developed during Paleoocene-Miocene and it has evolved to the foreland basin in Pliocene-Quaternary time. The present shelf morphology results mainly from combined effects of foreland subsidence and modern sedimentation overprinting that of the Late Pleistocene glaciation about 15,000 years ago.  相似文献   

4.
The outer rise on the distal periphery of a subduction system is caused by emplacement of an accreted load onto the flexed oceanic lithosphere. By examining the bathymetry and free-air gravity anomaly data collected by satellite observations and marine reflection seismic data collected during the TAIGER project, we demonstrate the characteristics of the flexural outer rise seaward of the Manila Trench. The region of the outer rise on the westernmost periphery of the Manila subduction system is characterized by the positive free-air gravity anomaly seaward parallel to the Manila Trench and the morphological rise at the south of the Manila subduction system. A flexure simulation is performed based on the flexural profiles along the southern Manila Trench-outer system and the resulting effective elastic thickness values may provide an alternative aspect for the spreading rates of the South China Sea basin. Since both the western periphery of the Taiwan collision belt and Manila subduction belt are dominated by the strain regime of extension of flexural origin, it appears that the strain regime of flexural extension associated with the flexural forebulge of the Western Taiwan Foreland Basin to the north, and the strain regime of flexural extension associated with the outer rise seaward of the Manila Trench to the south are meridionally interconnected. This revised understanding of the strain regime of flexural extension origin west of the Taiwan–Luzon convergent belt provides an alternative point of view on the strain regime offshore SW Taiwan.  相似文献   

5.
The collision between Eurasian and Pacific plates along the eastern margin of the Asian continent resulted in formation of a series of island-arcs, one of which is the Taiwan Island-arc, and the Taiwan Straits is a foreland basin in the continent-arc collision zone. The Quaternary fine-grained sediments occur evenly in the upper part of the basin, and the Pliocene deposits in the lower part. The stepped faults run in the deposits, indicating that the tectonic movement tended to weaken after the Pliocene. Strong seismic zones of Taiwan Island released large amount of plate overthrust-collision compressive stress and have their screen and prevention roles for the straits. Only the intersections between offshore NW-trending transform-like faults and seashore NE-trending faults on the southern and northern terminations of the Island are prone to strong earthquakes. The possibility of occurrence of M?≥?6 earthquake should be very low in the area for the planned future tunnel. Moreover, the seismic intensity is rapidly attenuated from the surface downward. Thus, the seismic intensity for the tunnel under the seabed will be much lower. In seismotectonic view, the construction of tunnel is feasible.  相似文献   

6.
The collision between Eurasian and Pacific plates along the eastern margin of the Asian continent resulted in formation of a series of island-arcs, one of which is the Taiwan Island-arc, and the Taiwan Straits is a foreland basin in the continent-arc collision zone. The Quaternary fine-grained sediments occur evenly in the upper part of the basin, and the Pliocene deposits in the lower part. The stepped faults run in the deposits, indicating that the tectonic movement tended to weaken after the Pliocene. Strong seismic zones of Taiwan Island released large amount of plate overthrust-collision compressive stress and have their screen and prevention roles for the straits. Only the intersections between offshore NW-trending transform-like faults and seashore NE-trending faults on the southern and northern terminations of the Island are prone to strong earthquakes. The possibility of occurrence of M ≥ 6 earthquake should be very low in the area for the planned future tunnel. Moreover, the seismic intensity is rapidly attenuated from the surface downward. Thus, the seismic intensity for the tunnel under the seabed will be much lower. In seismotectonic view, the construction of tunnel is feasible.  相似文献   

7.
胡毅  陈坚  许江 《海洋通报》2011,30(5):595-600
台湾海峡足我国量大的海峡,也是南海与东海进行物质和能量交换的主要通道.区域内地震、台风等灾害多发,潮流作用较强,同时受黑潮分支、南海暖流和东海环流等多种水系的影响,众多的山溪件中小型河流从海峡两侧流入海洋,为海洋沉积环境的研究提供了一个天然的实验场.基于台湾海峡的沉积环境分区、台湾海峡潮成沙脊的沉积环境、山溪性河流入海...  相似文献   

8.
海底沙体是海洋资源开发利用、环境保护、灾害防治和军事行动等必须密切关注的底质类型。台湾海峡沙体面积分布广泛,主要有台湾浅滩、台中浅滩及海峡内受中小型山溪性河流影响的沙体。近年来,台湾浅滩沙体空间分布、大型沙波与小型沙波形态特征及剖面结构研究等领域取得了许多新进展;台中浅滩不同区域的沙体演化对应了地貌发育的不同阶段;而海峡西侧陆架上残留的中小河流沙体地貌也获得了一些新发现。本文归纳了台湾海峡窄陆架上不同沙体的平面分布特征、剖面结构及成因。今后工作的重点应聚焦于进一步获取不同区域高分辨率的地层、地貌证据,并进行对比研究。这些工作能深化对末次盛冰期以来台湾海峡不同地区沙体成因、关联及演化的认识,并有助于了解人类海洋活动与海底沙体演化的响应关系,丰富海底沙体发育和演化理论。  相似文献   

9.
台西南盆地地质构造特征及油气远景   总被引:7,自引:3,他引:7  
本文从盆地的基本地质特征入手,分析了台西南盆地的地层、沉积、构造特征及油气条件,在进行盆地的定性分析的基础上,对盆地内的次级构造单元进行了类比,对盆地的含油气远景进行了评价,提出了该盆地的油气勘探方向。  相似文献   

10.
Sand wave deposition in the Taiwan Shoal of China   总被引:1,自引:0,他引:1  
The Taiwan Shoal is the convex terrain in the southern Taiwan Strait, the largest strait in China. In 2006 and 2007, 21 samples and more than 200-km sub-bottom data as well as 80-km near shore side-scan sonar data were gotten, which gave an initial image of the boundaries of the Taiwan Shoal and revealed the internal structure of the sand waves in this area. The results showed that the major component of the sediment samples was sand, and sand waves occurred everywhere in this area, which closely followed the range of the Taiwan Shoal as we know. The western boundary of the Taiwan Shoal thus reaches the 30 m isobaths near the shore, and as a result, its area potentially covers approximately 12 800-14 770 km2. The sand waves have different shapes under the complex ocean dynamics, and the height of sand waves in the near shore is usually smaller than that in the Taiwan Shoal. The number of sand waves ranged from 1-5 per kilometer, with more waves in the isobath-intensive area, suggesting the importance of topography for the formation of sand waves. The stratigraphic structure under the seabed has parallel bedding or cross bedding, and large dipping groove bedding can be seen locally in different parts, which may be the result of terrestrial deposition since the Late Pleistocene.  相似文献   

11.
晚玉木冰期台湾海峡的沉积环境   总被引:4,自引:1,他引:3  
对台湾海峡西部海域及河口平原14个钻孔剖面经孢粉、14C年龄和古地磁测定确定为晚玉木冰期的沉积层(Q33)样品进行了硅藻、有孔虫分析.结果表明,该时期海域的沉积层均属海相沉积,而河口平原区的沉积层则由海相和陆相地层交互组成.据此,提出了台湾海峡在晚玉木冰期属于水深在30~50m的浅海沉积环境的观点;阐述了这一与全球性气候冷暖更替所引起的海平面升降不一致现象是由于晚玉木冰期台湾海峡的地壳运动正处于间歇性下降时期,从而保持了浅海环境.  相似文献   

12.
Marine seismic reflection profiles from offshore SW Taiwan combined with onland geological data are used to investigate the distribution and nature of the deformation front west of Taiwan. Locations of the frontal structure west of Taiwan are generally connected in a linear fashion, although the alignment of frontal structures is offset by strike-slip faults. The deformation front begins from the northern Manila Trench near 21°N and continues northward along the course of the Penghu Submarine Canyon in a nearly N–S direction north of 21°N until it reaches the upper reaches of Penghu Canyon at about 22°15′N. The deformation front then changes direction sharply to the northeast. It connects to the Chungchou thrust fault or the Tainan anticline in the coastal plain and continues northwards along the outer Western Foothills to the northern coast of Taiwan near 25°N. Characteristics of structural style, strain regime, sedimentation and tectonics vary along the trend of the deformation front. Ramp anticlines, diapiric intrusion and incipient thrust faults are commonly associated with the deformation front. Variations in structural style along strike can be related to different stages of oblique collision in Taiwan. The deformation front (collision front) west of Taiwan can be considered as a boundary between contraction in the Taiwan orogen and extension west of the collision zone. The deformation front east of the Tainan Basin and its northward extension along the outer limit of the Western Foothills is the surface trace separating the foreland thrust belt from the nearby foredeep, not a boundary between the Chinese and Taiwan margins. The submarine deformation front off SW Taiwan is the surface trace separating the submerged Taiwan orogenic wedge from the Chinese passive continental margin, not a surface trace of the plate boundary between the Eurasian and Philippine Sea plates.  相似文献   

13.
This study focuses on the evolution of the Atlantic NW Moroccan Rharb continental shelf during the Neogene and Quaternary. This region is part of a foreland basin bounded by the Rif mountain belt and thus provides an interesting geological setting to study the interactions between eustasy and tectonics and the driving mechanisms controlling stratigraphic patterns. The results are supported by an interpretation of new data including high-resolution seismic lines coupled with an interpretation of industrial seismic lines and detailed logs of industrial wells completed by micropaleontologic analysis of cuttings. The stratigraphy reveals a succession of three mega sequences related to the transition from an underfilled to an overfilled stage reflecting the long-term evolution of the foreland system. Moreover, evidence of cyclical sea-level changes are visible in the upper megasequence composed of three depositional sequences assumed to be fourth-order sequences generated in response to the most recent 100-ka glacio–eustatic cycles. This study also shows the peripheral deformation of the Rharb shelf responsible for changes in the geometry of the deposits and thicknesses of the sedimentary fill during the Pliocene and Pleistocene. The most important change was triggered by the uplift of the Lallah Zahra Ridge corresponding to a major Quaternary kinematic boundary and the broad uplift of the southern shelf interpreted as a flexural uplift of the forebulge domain. The deformation-controlled sediment dispersal pattern consists of a progressive growth of the shelf accompanied with a progressive shift of depocenters from the North East to the South West and a general progradation to the North West along the southern border. This progressive filling has led to the confinement of the Rharb paleo-valley across the continental shelf. The complete filling of the palaeo-valley was followed by the development of a more than 70-m thick prodeltaic lobe at the front of the Oued Sebou river mouth during the Holocene.  相似文献   

14.
15.
花东盆地晚中新世以来沉积演化特征   总被引:1,自引:0,他引:1  
利用近年来在台湾东部海域采集的多道地震和多波速测深资料,对该海域花东海盆区晚中新世以来的沉积充填演化特征进行描述和分析。通过对花东海盆区域地形特征描述、层序地层格架的建立和地震剖面的解译,在本区晚中新世以来的沉积充填中刻画出6种典型地震相类型,并分析其对应的沉积相类型,包括浊积扇、浊积水道充填、块体流、沉积物波、海底峡谷-伴生沉积物滑塌变形-充填、深水扇沉积。结合地震相平面分布及垂向沉积相叠置关系,将晚中新世-第四纪沉积充填演化划分为3个阶段:晚中新世晚期开始受到块体流冲蚀阶段,到海底峡谷冲刷-沉积物失稳-峡谷充填-再侵蚀阶段,到峡谷输送的大量沉积物在上新世以来主要堆积发育了沉积物波、浊积扇、深水扇等沉积体系阶段。  相似文献   

16.
台湾海峡沉积盆地的演化与油气远景   总被引:2,自引:0,他引:2  
台湾海峡沉积盆地新生代以来构造演化经历了早第三纪陆缘裂谷、晚第三纪挤压收缩和第四纪隆起封闭等发育阶段,属残留陆缘裂谷,具有良好的油气远景,其中,海峡中部油气远景最佳。  相似文献   

17.
台湾海峡盆地的地质构造特征及演化   总被引:4,自引:0,他引:4  
分析了台湾海峡盆地形成的区域地质背景,将其纳入东海和南海盆地形成的框架内考虑,研究其区域演化阶段和盆地演化特征。结果表明,以台湾海峡盆地为中心的包括南海北部陆缘和东海在内的中国东南沿海地区在古新世—始新世期间处于统一的边缘海盆构造背景之下,而自晚始新世起,南海北部大陆边缘与其北部的台湾海峡地区、东海逐渐走上了不同的演化道路,前者向非典型的被动大陆边缘演变,而后者则继续其自古新世—始新世以来的演化进程,形成了自古新世至晚中新世间的4个有序分布的裂陷盆地群和相应的盆间弧体系。台湾海峡盆地有两次独特的前陆盆地经历,分别发生于晚渐新世—早中新世和晚中新世末至今,并且以第二次前陆最为强烈。  相似文献   

18.
台湾海峡地质构造特征   总被引:11,自引:1,他引:11  
杨肖琪  宋文隆 《台湾海峡》1996,15(2):127-136
台湾海峡及其邻区构造可分为3个一级构造单元,即闵浙中生代隆起区、台湾峡新生代坳陷区和台湾新生代岛弧褶断区。其中台湾海峡新生代坳陷区由海峡的主体和台湾西部兵陵平原区组成,它的东、西边界分别是台湾屈尺-老浓断裂带和粤滨外深断裂带。本文在以往海峡西岸东南海海长东-南澳断裂带研究基础上,对近年来台湾海峡、特别是海峡新生代坳陷区各次一级构造单元的深部地质结构,海底地形地貌、沉积特征、断裂构造、火成岩分布和地  相似文献   

19.
The geological setting south of the Tsengwen River and the Tsochen Fault is the transitional zone between the Tainan foreland basin and Manila accretionary wedge in Southwestern Taiwan. This transitional zone is characterized by the triangle zone geological model associated with back thrusts that is quite unique compared to the other parts of the Western foreland that are dominated by thrust imbrications. The Hsinhua structure, the Tainan anticline, and the offshore H2 anticline are the first group of major culminations in the westernmost part of the Fold-and-Thrust belt that formed during the Penglay Orogeny. Structures in the the Tainan and Kaohsiung areas provide important features of the initial mountain building stage in Western Taiwan. A deeply buried basal detachment with ramp-flat geometry existed in the constructed geological sections. A typical triangle is found by back thrusting, such as where the Hsinhua Fault cuts upsection of the Upper Pliocene and Pleistocene from a lower detachment along the lower Gutingkeng Formation. The Tainan structure is a southward extension of the Hinhua Fault and has an asymmetric geometry of gentle western and steep eastern limbs. Our studies suggest that the Tainan anticline is similar to the structure formed by the Hsinhua Fault. Both are characterized by back thrusts and rooted into a detachment about 5 km deep. The triangle zone structure stops at H2 anticline offshore Tainan and beyond the west of it, All the structures are replaced by rift tectonic settings developed in the passive continental margin. On the basal detachment, a major ramp interpreted as a tectonic discontinuity was found in this study. Above the northeastern end of the major ramp of basal detachment, the Lungchuan Fault is associated with a triangle system development, while at the southwestern end a thrust wedge is present. It could be deduced that a thrust wedge intrudes northwestward. The area below the major ramp, or equivalent to the trailing edge of the basal detachment, mud diapers often occur in relation to the thickest deposits of the Gutingkeng Formation and caused by the mechanism of detachment folding  相似文献   

20.
High resolution Chirp and Sparker data allowed definition and mapping of distinct seismic units in the shallow sediment record (~100 ms) acquired from the southern exit of the Bosphorus Strait; a dynamic depositional environment. The bottommost unit observed in the Chirp data (unit-3) is made up of marine-lacustrine sediments thinning seaward and onlaps the basement rocks which are represented by folded strata in the Sparker data, possibly lower to middle Pleistocene age. It is overlain by a series of prograding deposits along the shelf (unit-2) referring to sediment input from the northern sector depending on the water levels of the paleo Marmara lake’s during MIS 3. The uppermost deposits (unit-1) close to the Bosphorus Strait were represented by three separate subunits, unlike to relatively thin drape of sediments observed at the other places in the surrounding regions. The detailed definition of these subunits deduced from the closely-spaced reflection profiles and available radiocarbon ages helped to explain the history of the latest stratigraphic development depending on the connections between the Black Sea and the Sea of Marmara. In addition to the previously proposed major conduits, which controlled the sedimentary deposition at the southern exit of the Bosphorus, namely the Bosphorus Strait and Kurba?al?dere River, another submarine sedimentary pathway at the eastern bank of the strait’s channel seems to have delivered sediments directly into the basin.  相似文献   

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