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1.
万纳断裂带为一典型的右旋走滑系统,由其南段前锋的拉奈—沙捞越走滑-收缩叠瓦扇、北段尾端的南海西南次海盆西南端走滑-伸展叠瓦扇和中段的万安盆地走滑-拉分双重构造所组成,其动力主要源自中生代末以来华南—印支陆缘岩石圈的拆沉作用和南海海底扩张,它的走滑拉分作用直接导致了万安盆地的产生,对该海域油气等资源的形成与聚集起了重要的控制作用。  相似文献   

2.
南沙西部海域伸缩右旋走滑双重构造系统及其动力学过程   总被引:3,自引:0,他引:3  
万纳断裂带为一典型的右旋走滑系统,由其南段前锋的拉奈-沙捞越走滑-收缩叠瓦房,北段尾端的南海西南次海盆西南端走滑-伸展叠瓦扇和中段的万安盆地走滑-拉分双重构造所组成,其动力主要源自中生代末以来华南-印支陆缘岩的拆沉作用和南海海底扩张,它的直 拉分作用直接导了万安盆地的产生,对该海域油气等资源的形成与聚集起了重要的控制作用。  相似文献   

3.
基于渤海辽北地区钻井资料和三维地震资料精细解释,对走滑断裂发育特征开展精细研究,并进一步完成对走滑转换构造的宏观判识和精细刻画,总结走滑转换构造对圈闭样式的差异控制作用。研究结果表明:(1)辽北地区断裂体系整体表现出强烈的右旋走滑性质,在走滑断裂叠接带、弯曲、尾端等构造位置,因构造应力调整而发育大量走滑转换构造;(2)依据走滑转换带的力学性质划分为增压型和释压型2大类,每一大类依据断裂空间展布关系进一步细化为单支弯曲型和双支叠复型,其中,单支弯曲型表现为单条走滑断层平面呈现“S”型变形,双支叠复型则表现为右旋左阶或右旋右阶;(3)增压型和释压型走滑转换构造控制发育的圈闭类型分别以断背斜和断块构造圈闭为主,增压型走滑转换构造控制的圈闭相对于释压型具有更大的勘探潜力。该研究丰富了走滑转换构造体系,填补了辽北地区走滑转换构造研究的空白,对渤海海域郯庐走滑断裂带油气勘探具有一定的借鉴指导意义。  相似文献   

4.
南海西部断裂系研究及其物理模拟实验证据   总被引:3,自引:1,他引:3  
南海西部断裂系是由四条典型的走滑断裂所组成的断裂系统,是南海扩张的西部边界.此断裂系主要是在白垩纪以来的印-藏碰撞、新生代印支挤出和南海扩张的共同作用下形成的.通过模拟实验,探讨此断裂系的成因、演化过程,认识到此断裂系经历了五期构造运动.  相似文献   

5.
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   

6.
南昆嵩地区是万安盆地西部负向构造单元,其中部N–S向断裂贯穿南北,独特的构造特征使其成为研究万安盆地西部构造演化与区域断裂走滑活动的窗口。将研究区沉积地层划分为3套构造层,通过回剥法绘制南昆嵩地区构造–沉积充填剖面,并计算南昆嵩地区构造沉降量以及构造沉降速率,论述南昆嵩地区构造演化史与沉降过程以及控制因素。研究结果表明:下部构造层和中部构造层中断裂组合样式主要为卷心型断层、“Y”型断层、阶梯状断层和高角度花状构造等,断裂延伸方向大致可分为:N–S向、W–E向和NE–SW向3种;上部构造层断裂不发育,为稳定沉积;在区域走滑断裂以及南海扩张运动的控制下,南昆嵩地区始新世以来构造演化经历4个阶段:初始裂谷期、伸展断拗期、走滑改造期和热沉降期,新生代地层构造性质也表现为以伸展与走滑作用为主–走滑断裂控制–热沉降的三段式转变。  相似文献   

7.
南海南部廷贾-西巴兰线断裂是一条规模巨大的北西向走滑断裂,渐新世开始活动,早期具有强烈的右旋走滑特征,晚中新世以来走滑方向变为左旋,更新世至今,走滑方向变为右旋,是曾母盆地与北康盆地、南沙海槽的分界。为了理清廷贾-西巴兰线断裂特征与曾母盆地油气成藏的关系,通过对断裂两侧地震剖面特征、重磁特征、地热流分布特征以及地壳性质和岩石圈厚度的分析,探讨该断裂在曾母盆地形成演化及油气成藏中的控制作用。研究表明:断裂活动为曾母盆地后期的沉积提供了丰富的物源,断裂走滑作用导致曾母盆地具有良好的圈闭,后期的反向走滑使得盆地的沉积中心由南向北迁移;断裂沟通深部热源,有利于油气生成,形成的伴生断层是盆地油气运移的主要通道。  相似文献   

8.
莱州湾凹陷位于渤海南部海域,为中生界基底之上发育的新生代半地堑.郯庐断裂带分东西两支穿过莱州湾凹陷东部,在新生代盖层中表现出渤海最复杂最典型的为NNE向的右旋走滑断裂特征.其中东支断裂在渐新世以后活动强烈,发育多条NNE向走滑断层及NE向伴生断层组成的复杂断裂带.走滑断裂带内断层展布符合右旋单剪作用下的脆性走滑剪切模式,地震方差切片存在右旋运动拖拽断裂证据.通过对主断裂活动期次分析表明,研究区主要有三期大的构造活动,同时形成了三期构造反转.应力分布的局域性导致了形变特征的差异性,产生了褶皱、挤压反转、掀斜断块、花状构造等典型的构造类型.研究区首次利用三维地震资料对本区构造特征进行了分析,研究认为走滑活动形成了良好的构造背景、优越的油源及运移等成藏条件,具有较大的油气勘探潜力.  相似文献   

9.
惠民凹陷走滑构造特征及其对油气的控制   总被引:1,自引:0,他引:1  
济阳坳陷内广泛分布着走滑构造系统,其形成主要受控于其东边的郯庐断裂带。通过详细的地震解释,得出了济阳坳陷深层的绝大多数走滑构造以负花状构造为特征,表现出离散式走滑或走滑伸展型断裂性质,且多是在早期正断层的基础上继承发育。平面上主要以NNE向与NE向展布。  相似文献   

10.
南海北部陆缘记录了南海形成演化的历史,但是其新生代构造沉积演化特征在东段和西段的差异及其原因目前还不太清楚。本文分别在珠江口盆地和琼东南盆地的深水区选择了数口构造地理位置相似的井通过精细地层回剥分析,重建了两沉积盆地的沉积速率和沉降速率并结合前人研究成果进行了对比分析。研究结果发现,两沉积盆地在裂陷期的沉积和沉降特征基本相似,但是两者在裂后期的构造沉积演化特征差异明显。珠江口盆地深水区沉积和沉降速率都表现为幕式变化特征,其中沉积速率表现为“两快三慢”的特征而沉降速率表现为“两快一慢”的特征。琼东南盆地深水区的沉积速率表现为“地堑式”变化特征,但是沉降速率表现为“台阶式”上升的变化特征。琼东南盆地“台阶式”上升的沉降速率推测主要是受到海南地幔柱伴随红河断裂的右旋走滑而向西北漂移的影响,这也与南海西北部的岩浆活动以及周围盆地的沉降特征吻合。红河断裂在2.1 Ma BP的右旋走滑控制了琼东南盆地1.8 Ma BP以来的快速沉积和加速沉降分布。  相似文献   

11.
The analysis of the structure of the cryolithozone, facies, and thicknesses of the Quaternary sediments and the results of the physicochemical mathematical modeling of the modern shelf of the western part of the Laptev Sea support the influence of the Late Pleistocene glaciations on the heat conditions and the distribution of the permafrost in the area. A ~200-m thick glacier formed under aerial conditions from atmospheric precipitation represented the metamorphosed snow cover. According to the modeling, the long-living (from 60?50 to 10?4 ky) glacier reduced the thickness of the permafrost rocks in the reviewed shelf area for 280–360 m. The Holocene marine transgression additionally decreased the thickness from 50–140 m on the inner shelf to 220–350 m on the outer shelf. The modern submarine cryolithozone 450-0 m thick is wide-spread in the studied region from the coast to the shelf boundary (isobaths of 130–140 m), where it pinches out at a distance of ~380 km from the coast at a depth of ~250 m above the sea level.  相似文献   

12.
We analyze the components of the carbon system of the Sevastopol bay waters and the balance of main sediment-forming substances using the data of field investigations in 1998–2008. The interannual variations of total inorganic carbon and the equilibrium partial pressure of carbon dioxide in the bay water are noted. An increase in the flux of carbon dioxide into the bay and in the content of organic carbon in bottom sediments is revealed, and an explanation of this phenomenon is given. The priority accumulation of organic carbon in the sediments of the bay is established. We assess the interannual variation in the relative abundances of organic and inorganic carbon as an index of the carbon cycle stability.  相似文献   

13.
双壳贝类血淋巴中儿茶酚胺的检测方法初步研究   总被引:1,自引:0,他引:1  
研究的目的是探索一种检测双壳贝类血淋巴中儿茶酚胺含量的方法。以栉孔扇贝(Chlamysfarreri)和长牡蛎(Crassostreagigas)为实验对象,研究了取样、抗氧化剂、氧化铝用量以及Tris缓冲液用量等对实验结果的影响。结果表明,高效液相色谱电化学检测器法(HPLC-ECD)可以灵敏高效地对双壳贝类血淋巴中儿茶酚胺进行定性、定量检测。实验表明,取样时间最长不超过1.5min;还原性谷胱甘肽作抗氧化剂效果较好;前处理各试剂与血样量的最适配比为血样量1.5mL,Tris缓冲液(1.5mol/L,pH8.6)1mL和氧化铝25mg;水洗后离心并尽可能吸干氧化铝中的水分。去甲肾上腺素、肾上腺素和多巴胺的回收率分别为53%~69%、47%~73%和48%~56%。  相似文献   

14.
We generalize and analyze the state of investigations of the influence of river waters on the hydrologic structure of the Black Sea. Specific features of the water, regime and hydrography of rivers flowing into the sea, data on the discharge of rivers, and intrayear and interyear variability of the discharge are presented. We discuss and analyze works studying the transformation of river waters, routes of desalinized sea waters, and their influence on the thermohaline structure and dynamic regime of the sea. Translated by Peter V. Malyshev and Dmitry V. Malyshev  相似文献   

15.
为研究黄河入海径流变化条件下河口附近海域盐度扩散特征,以更好地保护河口海域生物资源多样性,本文以黄河下游利津水文站的长序列实测径流数据资料为基础,利用近海水动力模型FVCOM,分析径流变化对黄河口海域盐度的影响规律。结果表明:黄河口与莱州湾之间存在顺时针的环流系统,在余流作用以及涨落潮方向的影响下,黄河冲淡水长期向莱州湾扩散;丰水期黄河冲淡水几乎影响了整个莱州湾,27盐度锋可以到达莱州湾中部,27等盐线的表层包络面积为2 665.61 km2,占莱州湾的1/4左右,枯水期低盐度水只有向南扩散的趋势,27以下的低盐度水集中分布在黄河口门附近,27等盐线的表层包络面积只有199.65 km2;5月份,随着入海径流量增加,27等盐线扩散的范围、距离、方向都会发生明显变化。在对近海生物资源有迫切保护需求的情景下,适当减少其他用水户供水量以增加入海生态径流量,可以有效改善黄河口海域附近的盐度情况,为生物资源的生长繁殖创造良好条件。  相似文献   

16.
We analyze the results of numerical calculations performed according to the three-dimensional interdisciplinary model of an ecological system of the Black-Sea shelf zone near the estuary of the Danube. The complete system of equations of hydrothermodynamics is solved together with transport equations of the advection-diffusion-reaction type used to describe the transformation of a substance (nitrogen) between the components of the characteristic vectors of the ecosystem: plankton, detritus, and biogenic elements (nitrates). We describe the distinctive features of the circumcontinental distribution of components obtained as a result of numerical experiments and present arguments for the conclusion that the ecosystem of the Danube estuary water area plays the role of a buffer zone between the press of the Danubian biogenic pollutions and the neighbouring areas of the shelf zone and open sea. Translated by Peter V. Malyshev and Dmitry V. Malyshev  相似文献   

17.
The authors have previously determined that the effectiveness and failure pattern of the ice cover caused by flexural-gravity waves generated by a submerged body motion near the bottom ice can greatly depend on the depth of the water area. In its turn, the presence of a ledge on the ice surface may affect a wave propagation pattern. This paper presents an experimental study of the bottom contour influence on the deflection and length of flexural-gravity waves. The authors describe a numerical model for the analysis of the deformed state of ice caused by hydrodynamic loads due to a submarine motion, taking into account the bottom contour. The experiments are carried out in the ice tank. The results of calculations and experiments are compared.  相似文献   

18.
Ten years of semistationary studies of the interaction of the ice cover and the coastal relief of the Kandalakhsa Gulf in the White Sea allowed us to reveal the peculiarities of these processes in the warm and cold years and the mechanisms of the origination of ice forms, including ice tents, which govern the character of the tidal flats. Three dynamic fast ice zones are distinguished by their geomorphological location, morphology, and ice dynamics. The dependence of the mechanisms and volumes of the enrichment of the fast ice in the sediments on the coastal zone??s relief was established. At the coast of the Kindo Peninsula (Velikaya Salma Strait), the ice mostly contains fine-sandy sediments. Coarser sediments, including boulders, are occasional and frozen into the ice at the contact of the fast ice and the bottom. At the expense of the ice??s spreading by 4?C6 times in the warm years and 2?C4 times in the cold years, several thousand tons of sediments mostly from the tidal flat??s surface (100?C700 m3 from 1 km of coast in the wide tidal flats and <50 m3 on the steep coasts) are delivered to the water area.  相似文献   

19.
A relationship between paths of the Kuroshio and Kuroshio Extension (KE) is investigated, using the satellite-derived altimetry dataset of 1993–2008. When the Kuroshio takes the nearshore nonlarge meander path or typical large meander path and resultantly goes through the deeper channel (about 2500 m) of the Izu-Ogasawara Ridge, the KE path adopts a relatively stable state with the two quasi-stationary meanders. On the other hand, when the Kuroshio takes the offshore nonlarge meander path and then passes over the shallower part of the Ridge (about 1000 m), the KE path tends to be convoluted, i.e., an unstable state.  相似文献   

20.
北黄海海域大气湍流强度特征及风速标准差相似性分析   总被引:1,自引:1,他引:0  
根据国家海洋局"908"专项北黄海海区海洋气象观测资料,计算了2007~2008年间该海区4个不同季节的大气湍流强度并与其他海区及陆地下垫面大气湍流值相比较.北黄海海区大气湍流强度量级为10-2,比陆地下垫面大气湍流强度低一个量级.由于海洋的特殊性质,对秋季大气湍流强度日变化的分析发现,在大气湍流强度的影响因素中,海洋的热力作用相对较大.对水平方向风速标准差是否满足Monin-Obukhov相似关系进行了探讨,数据显示,在不稳定层结下冬季水平方向无量纲风速标准差与Z/L的关系,基本满足1/3次方律.秋冬在不稳定层结下垂直方向风速标准差满足Monin-Obukhov相似理论.  相似文献   

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