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1.
台湾海峡新生代断裂构造及其形成演化   总被引:4,自引:0,他引:4  
李赶先 《热带海洋》1994,13(2):17-24
论述了台湾海峡新生代断裂构造基本特征,划分出海峡及两侧两大断裂系,探讨了断裂系的形成演化过程,阐明了断裂构造的形成演化与海峡裂谷演化的对应关系,并进一步探讨了海峡裂谷的演化模式。文中对NW向断裂折射平移和扇状收敛的首次发现,为弧陆碰撞引起海峡裂谷封闭物观点提供了重要佐证。  相似文献   

2.
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   

3.
阳江-一统东断裂是珠江口盆地西部一条重要的NW向区域大断裂,是盆地东西分块的重要分界线。南海北部陆缘在新生代经历了大陆裂谷-裂离-海底扩张-热沉降的过程,阳江-一统东断裂在新生代的活动是这一复杂过程的一部分。对分处断裂两侧的从陆架延伸至洋陆边界的两条NNW向多道地震剖面进行了地质解释,研究了珠江口西部的构造和沉积特征。利用2D-Move软件及构造回剥法建立了平衡剖面模型,计算了断层活动速率,结合构造位置、构造演化史、标志构造和应力分析推断了阳江-一统东断裂在新生代的活动史。结果表明,阳江-一统东断裂可以中部坳陷带为界分为两段,从65Ma到32Ma,断裂整体表现为左旋活动,继承了断裂在中生代时期的先存左旋走滑,其中,在此时期断裂南段主要表现为伸展活动,伴随着轻微的左旋走滑,这种伸展活动控制了云开低凸起的形成和演化;从32Ma到23.8Ma,断裂北段的左旋走滑活动持续,而南段逐渐转为轻微的右旋走滑或左旋活动停止。在23.8Ma之后,断裂南段的右旋走滑活动持续,北段的左旋走滑逐渐停止,或转为轻微的右旋走滑。阳江-一统东断裂的这种走滑旋向的转变可能与在珠江口盆地南部洋陆过渡带区域的岩浆底侵作用有关。根据对盆地构造活动强度和裂谷格架的分析,认为阳江-一统东断裂的新生代活动在珠江口盆地裂谷伸展过程中起到了应力调节的作用。  相似文献   

4.
立足于大西洋的形成与演化,划分了贝宁盆地构造演化阶段,厘定了裂陷期盆地的边界,分析了盆地结构和构造特征,明确了盆地构造样式。贝宁盆地经历裂陷期、漂移期两个构造演化阶段,不发育盐岩。受早白垩世裂陷期盆地东、西部应力差异控制,盆地形成了东部拉张构造区和西部走滑构造区,盆地裂谷分布具有"东宽西窄"的特征。东部拉张构造区发育近东西向断裂体系,主要为拉张作用形成的铲式正断层,西部走滑作用区发育NE—SW向走滑断裂体系,发育陡直的走滑断裂,主要为走滑作用形成的走滑断层。受早白垩世东、西部应力差异和晚白垩世构造反转、新生代重力滑脱作用的控制,盆地发育拉张、扭张、挤压、重力滑脱4类构造样式,丰富的构造样式为盆地构造圈闭发育提供了有利的条件。  相似文献   

5.
东南亚地区发育100多个新生代沉积盆地,这些沉积盆地经历了不同程度的裂谷作用。为了指导东南亚油气勘探,通过对盆地构造-沉积演化进行分析,系统研究了东南亚地区盆地油气成藏组合的要素特征,并探讨了裂谷作用对油气成藏组合的影响。研究结果认为:东南亚地区盆地构造-沉积演化经历了同生裂谷早期、同生裂谷晚期、后裂谷早期和后裂谷晚期4个裂谷作用阶段。根据裂谷作用阶段和在相应裂谷作用阶段形成的储层类型,从深到浅划分出4套油气成藏组合:深部成藏组合、下部成藏组合、中部成藏组合和上部成藏组合。深部成藏组合发育同生裂谷早期湖相浊积砂岩、湖相冲积扇储层,下部成藏组合发育同生裂谷晚期海进时期河流-三角洲砂岩储层,中部成藏组合发育后裂谷早期海相碳酸盐岩储层,上部成藏组合发育后裂谷晚期海退时期河流-三角洲砂岩储层。其中,中部成藏组合发育的后裂谷早期海相碳酸盐岩储层勘探潜力最大。  相似文献   

6.
从张扭性断陷盆地的断裂特征入手,结合构造动力学形成机制,总结了恩平凹陷的构造样式特征及有利圈闭类型,并探讨了构造样式对烃源岩的形成和油气富集区带的控制作用。结果表明:恩平凹陷为双向伸展的上下构造层变形系统的叠合,即古近系为NE—EW向伸展构造系统,新近系为NW—NWW向伸展—张性扭动构造系统;发育了4大类伸展型构造样式,构造样式演化控制了半地堑结构、烃源岩发育情况、油气的初始运移方向和断裂构造带与圈闭类型分布,为新生界油气藏的形成创造了有利条件。  相似文献   

7.
宽扎盆地油气地质特征   总被引:1,自引:0,他引:1  
安哥拉宽扎盆地是典型被动大陆边缘盆地,完整经历了前裂谷阶段、裂谷阶段、过渡阶段及漂移阶段等4个构造演化阶段,形成了盐下、盐间和盐上3套沉积层序,并各自形成含油气系统。在对宽扎盆地构造演化、沉积特征及油气成藏条件进行分析后认为:宽扎盆地盐下、盐间和盐上3套沉积层序的油气成藏主控因素分别为拉伸断陷、盐隆起及盐构造运动;宽扎盆地盐下有利勘探区为盆地东部白垩系地堑构造区,盐间有利勘探区为盆地中东部盐隆发育部位,盐上有利勘探区为盆地东部古近系和新近系地堑发育部位;宽扎盆地今后勘探工作重点应放在盆地东部白垩系地堑构造区的盐下碳酸盐岩储层目标。  相似文献   

8.
位于巴西东岸的南大西洋被动大陆边缘盆地-桑托斯盆地是我国海外油气勘探的重要区块。通过地震资料分析,结合叠合盆地演化原理以及南大西洋演化历程,将桑托斯盆地的构造演化阶段划分为前裂谷期、裂谷期、过渡期、漂移期4个阶段,对应克拉通、裂谷、坳陷、被动大陆边缘4类原型盆地。原型盆地的时空匹配关系为桑托斯盆地形成超大型的含油气系统提供了极为理想的构造条件。结合前人的研究成果对盆地"生储盖"组合分析,得出桑托斯油气富集成藏的规律,即"厚盐区盐下富集;薄盐区盐上富集"。通过对盆地区域构造史以及所得的地震资料分析,认为在目前重视不足的盐下东部坳陷地区存在厚层优质的湖相烃源岩,烃类沿着基底大断裂以及不整合面运移,被过渡期蒸发盐岩所阻挡,形成以构造-地层复合圈闭和地层不整合遮挡圈闭为主的油气藏。  相似文献   

9.
下刚果-刚果扇盆地位于西非被动大陆边缘,是典型的裂谷与被动陆缘叠合盆地。该区以往的研究多集中于盐上层系,对基底断裂研究较少。以构造分析为基础,探讨了基底断裂复活及其对盐上层系构造变形和油气分布的影响。结果表明,研究区盐下裂谷层系具有"两坳夹一隆"的构造格局,大西洋枢纽带夹持于内裂谷带和外裂谷带之间;基底断裂复活主要发生在紧邻大西洋枢纽带西侧、呈狭长带状分布的基底断裂复活带,断裂复活形式主要表现为继承性,其次为构造反转;基底断裂复活不仅对盐上层系的构造变形具控制作用,而且为油气从盐下层系向盐上层系运移提供了良好的垂向通道条件,是外裂谷带盐下油气向盐上层系运移的关键部位。  相似文献   

10.
利用在南海西南海盆南缘首次发现的花岗闪长岩样品,通过等离子质谱仪、岩相显微镜和电子探针等设备对其地球化学组成进行了分析;并对其组分中黑云母矿物进行了40Ar/39Ar年代学研究。40Ar/39Ar等时线年龄显示岩石的结晶年龄为(109.5±1.5)Ma,是早白垩世岩浆入侵的产物。地球化学测试表明:样品以富SiO2、K2O,高Al2O3、贫TiO2为特征。地球化学-构造判别图解显示,样品属于火山弧花岗岩,为造山类花岗岩。样品可能是海盆早期张裂阶段裂谷系组成的重要岩石类型,而裂谷拉张的过程可能与现代红海的演化相似,经历了裂谷沉陷过程,当裂谷宽度、深度达到一定规模时,洋壳随之而产生。该样品的发现,揭示其产出位置可能是南海西南海盆的南部边界,而且是洋盆扩张初期断裂系统的组成部分,为探讨南海的张裂、形成与演化历史提供了新的线索。  相似文献   

11.
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   

12.
于1986-1991年,应用地震地质方法,对台湾海峡的地震地层和地质构造进行调查,采用地震剖面资料,结合区域地质特征,对台西盆地的构造演估进行研究,认为该盆地由厦澎坳陷,乌丘屿坳陷,新竹坳陷和台湾坳陷等组成,其构造演化经历了中生代末-中始新世初始张裂,晚始新世一渐新世全面断裂,中新世构造调整,以及中新世末以来挤压-收缩-封闭等阶段,现今已成为残留陆缘裂谷盆地,是陆缘裂谷从产生到衰亡的一个典型实例。  相似文献   

13.
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   

14.
The necessity and the preliminary tentative plan for the construction of the undersea tunnel across Taiwan Strait are expounded in this atricle. The strait undersea tunnels, which have been built and investigated in the world, and their engineering characteristics and construction methods have been introduced herein briefly. Taiwan has been a part of China since ancient times and the people between the mainland and Taiwan are kindred compatriots in the extended family of the Chinese multinational country. For a long time, the people between southeast of China and Taiwan have had frequent communication in economy and culture. With the progress of times and the need of development, it has been put forward to build a safe and reliable undersea tunnel that is not affected by the environment across Taiwan Strait, and one which is also a magnificent project for the China in the long-term. Whether by using a bridge or an undersea tunnel or both across the strait is a problem worthy of further research. According to such conditions as the weather of Taiwan Strait, depth of water, undersea terrain, possibility of engineering and hydrological geology under the sea, as well as the possibility of Taiwan Strait as a main shipping passage from south to north of China and the experience of existing passage across strait in the world, the primary analysis shows that the scheme of an undersea tunnel should be considered. Therefore the concept of the undersea tunnel engineering across Taiwan Strait is introduced in detail here.  相似文献   

15.
The necessity and the preliminary tentative plan for the construction of the undersea tunnel across Taiwan Strait are expounded in this atricle. The strait undersea tunnels, which have been built and investigated in the world, and their engineering characteristics and construction methods have been introduced herein briefly.?Taiwan has been a part of China since ancient times and the people between the mainland and Taiwan are kindred compatriots in the extended family of the Chinese multinational country. For a long time, the people between southeast of China and Taiwan have had frequent communication in economy and culture. With the progress of times and the need of development, it has been put forward to build a safe and reliable undersea tunnel that is not affected by the environment across Taiwan Strait, and one which is also a magnificent project for the China in the long-term.?Whether by using a bridge or an undersea tunnel or both across the strait is a problem worthy of further research. According to such conditions as the weather of Taiwan Strait, depth of water, undersea terrain, possibility of engineering and hydrological geology under the sea, as well as the possibility of Taiwan Strait as a main shipping passage from south to north of China and the experience of existing passage across strait in the world, the primary analysis shows that the scheme of an undersea tunnel should be considered. Therefore the concept of the undersea tunnel engineering across Taiwan Strait is introduced in detail here.  相似文献   

16.
关于台湾海峡分界的探讨   总被引:1,自引:0,他引:1  
周定成 《台湾海峡》2010,29(2):149-153
台湾海峡介于台湾岛与大陆之间,是东海与南海的通道.关于台湾海峡范围的划分,海峡之东常以台湾岛两端(北为富贵角,南为鹅銮鼻)为界;海峡之西以大陆的平潭岛等为北界,东山岛或南澳岛为南界.为了更客观和准确地划分台湾海峡范围,本文根据海洋地理学中"海峡"的概念及对世界海峡类似实例的分析,并按照台湾海峡区域地形、地质等特征进行了分界.作者认同台湾海峡北口位于福建省平潭岛至台湾富贵角,但认为其南口应位于广东南澳岛至台湾曾文溪河口南岸.在此南、北口之间为台湾海峡范围.台湾海峡地形、地质等特征明显,与台湾及大陆紧密关联,并具有东海延伸入内的特点.而北口之北的闽东北海底,海峡特征明显消失.此南口为东海与南海的交汇处,其南属于南海的台湾浅滩及其外缘,其地形、地质特征也与海峡的显著不同.本研究结果对于更准确地划分台湾海峡范围及区域海洋研究与实践等方面都具有多方面的意义.  相似文献   

17.
台湾海峡两岸第四纪生物群特征及古地理演变   总被引:5,自引:0,他引:5  
本文以大量古生物、古文化遗址及测年资料,分析台湾海峡两岸受新构造运动影响和自更新世以来的古地理演变,从而证明了台湾是中国神圣领土不可分割的一部分。  相似文献   

18.
High-resolution Sea Beam bathymetry and Sea MARC I side scan sonar data have been obtained in the MARK area, a 100-km-long portion of the Mid-Atlantic Ridge rift valley south of the Kane Fracture Zone. These data reveal a surprisingly complex rift valley structure that is composed of two distinct spreading cells which overlap to create a small, zero-offset transform or discordant zone. The northern spreading cell consists of a magmatically robust, active ridge segment 40–50 km in length that extends from the eastern Kane ridge-transform intersection south to about 23°12′ N. The rift valley in this area is dominated by a large constructional volcanic ridge that creates 200–500 m of relief and is associated with high-temperature hydrothermal activity. The southern spreading cell is characterized by a NNE-trending band of small (50–200 m high), conical volcanos that are built upon relatively old, fissured and sediment-covered lavas, and which in some cases are themselves fissured and faulted. This cell appears to be in a predominantly extensional phase with only small, isolated eruptions. These two spreading cells overlap in an anomalous zone between 23°05′ N and 23°17′ N that lacks a well-developed rift valley or neovolcanic zone, and may represent a slow-spreading ridge analogue to the overlapping spreading centers found at the East Pacific Rise. Despite the complexity of the MARK area, volcanic and tectonic activity appears to be confined to the 10–17 km wide rift valley floor. Block faulting along near-vertical, small-offset normal faults, accompanied by minor amounts of back-tilting (generally less than 5°), begins within a few km of the ridge axis and is largely completed by the time the crust is transported up into the rift valley walls. Features that appear to be constructional volcanic ridges formed in the median valley are preserved largely intact in the rift mountains. Mass-wasting and gullying of scarp faces, and sedimentation which buries low-relief seafloor features, are the major geological processes occurring outside of the rift valley. The morphological and structural heterogeneity within the MARK rift valley and in the flanking rift mountains documented in this study are largely the product of two spreading cells that evolve independently to the interplay between extensional tectonism and episodic variations in magma production rates.  相似文献   

19.
The development of an anomalously deep rift appears to be a common characteristic of the evolution of microplates along the East Pacific Rise, including the Galapagos, Easter, and Juan Fernandez microplates. We investigate crustal rifting at Endeavor Deep on the Juan Fernandez microplate using bathymetry, gravity and side scan sonar data. An initial phase of lithospheric extension accompanied by extensive subsidence results in the formation of a very deep rift valley (up to 4 km of relief, 70 km long and 20 km wide). Morphological observations and gravity data derived from GEOSAT satellite altimetry show the subsequent initiation of crustal accretion and development of a mature spreading center. Recent models of the kinematics of microplate rotation allow the amount of opening across Endeavor Deep over the past 1 m.y. to be quantified. We develop a simple mechanical model of rifting involving block faulting and flexural response to explain the gravity signature over the rift valley. The Bouguer gravity anomaly is asymmetric with respect to the surface topography and requires that a shallow-dipping fault on the western wall of the valley dominate the extension at Endeavor Deep. Consideration of three similar microplate rift valleys leads us to suggest that asymmetric rifting is the characteristic process forming microplate deeps.  相似文献   

20.
To study the Taiwan Strait (TS), an unusual sea area, the numerical model in marginal seas of China is used to simulate and analyze the tidal wave motion in the strait. The numerical modeling experiments reproduce the amphidromic system of the M2 tide in the south end of the Taiwan strait, and consequently confirm the existence of the degenerate amphidromic system. On this basis, further discussion is conducted on the M2 system and its formation mechanism. It can be concluded that the tidal waves of the TS is consisted of the progressing wave from the north entrance and the degenerate amphidromic system from the south entrance, in which the progressing wave from the north entrance dominates the tidal wave motion in the strait. Except for the convergent effect caused by the landform and boundary, the degenerate amphidromic system produced in the south of the strait is another important factor for the following phenomena: the large tidal range in the middle of the strait, the concentrative zone of co-amplitude and co-phase line in the south of the strait. The degenerate amphidromic system is mainly produced by the incident Pacific Ocean tidal wave from the Luzon strait and the action by the shoreline and landform. The position of the amphidromic point is compelled to move toward southwest until degenerating by the powerful progressing wave from the north entrance.  相似文献   

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