Mass-transport deposits on the Rosetta province (NW Nile deep-sea turbidite system, Egyptian margin): Characteristics, distribution, and potential causal processes   总被引：2，自引：0，他引：2  

Sbastien Garziglia  Sbastien Migeon  Emmanuelle Ducassou  Lies Loncke  Jean Mascle 《Marine Geology》2008,250(3-4):180-198

In the Nile deep-sea turbidite system (NDSTS), the province fed by the Rosetta branch of the Nile delta is characterised by the recurrent activity of gravity processes. Seven mass-transport deposits (MTDs) were recognised from the upper to the mid slope, downstream from imbricated scars (~ 30 km-long, ~ 200 m high) running along the shelf edge nearby the Rosetta canyon. Extending on surfaces between 200 and 5000 km², with estimated volumes from 3 to 500 km³, these MTDs represent about 40% (up to 90% locally) of the total Pleistocene–Holocene sedimentary thickness. Three types of MTDs can be distinguished on the basis of their scale. Each has also a distinctive internal configuration and distribution within the Rosetta depositional setting. Age estimates of two MTDs point towards relationships between climate and submarine mass failures through sea-level changes, sediment supply, or a combination of both. Additionally, the presence of gas in the sediment and earthquake shaking may have concurred to trigger large-scale failures on the low slope angles (1°–2°) of the Rosetta area.  相似文献   

牛庄洼陷浊积岩储层定量描述方法及应用     

王奇韵 《地质论评》2023,69(Z1):297-298

  相似文献   

南海北部陆坡深水曲流水道的识别及成因   总被引：3，自引：0，他引：3  

袁圣强  曹锋  吴时国  姚根顺  王海荣  李丽 《沉积学报》2010,28(1):68-75

深水水道是深水沉积体系中重要的组成单元,其作为潜在的油气储集体也被油气行业所关注。深水水道多处于深水环境下的沉积地层中,因此对于其直接的观测和研究都比较困难。基于近年新采集的多道2 D和3 D地震资料,利用相干时间切片、RMS均方根振幅、3D振幅可视化等地球物理手段对南海北部陆坡深水水道进行了识别和研究。该水道为更新世深水曲流水道,与来自中南半岛的浊流侵蚀有关,水道呈SW—NE向展布,侧向侵蚀特征明显。3D振幅可视化图显示该水道轴部为强振幅反射,推测为富砂充填,其余部分为弱振幅反射,推测为富泥充填,这点与世界已钻水道特征一致。深水曲流水道的形成过程和内部结构复杂,其内部砂体与泥岩常互层出现,泥岩的封堵作用会阻碍流体的流动或形成超压,同时也可起到良好的盖层作用,因此对于深水曲流水道的勘探和开发要重视这个问题。   相似文献   

鄂尔多斯盆地延长组湖盆中部长6厚层砂体成因分析   总被引：3，自引：0，他引：3       下载免费PDF全文

惠 潇张海峰  张东阳路 霖 《中国地质》2008,35(3):482-488

笔者对鄂尔多斯盆地湖盆中部地区延长组长6物源分析、沉积相类型、坡折带控砂、砂体分布规律等进行了研究。东北、西南两大物源提供了充足的物质基础,发育三角洲牵引流作用的沉积砂岩和重力搬运的浊积砂岩,主要为叠置水下分流河道、河口砂坝-水下分流河道和滑塌浊积岩等不同类型的砂体组合,形成了垂直湖岸线和平行湖岸线展布的巨型厚砂岩分布带。  相似文献   

Turbidite system architecture and sedimentary processes along topographically complex slopes: the Makran convergent margin     

JULIEN BOURGET  SEBASTIEN ZARAGOSI  NADINE ELLOUZ‐ZIMMERMANN  NICOLAS MOUCHOT  THIERRY GARLAN  JEAN‐LUC SCHNEIDER  VALENTINE LANFUMEY  SIGFRIED LALLEMANT 《Sedimentology》2011,58(2):376-406

This study investigates the morphology and Late Quaternary sediment distribution of the Makran turbidite system (Makran subduction zone, north‐west Indian Ocean) from a nearly complete subsurface mapping of the Oman basin, two‐dimensional seismic and a large set of coring data in order to characterize turbidite system architecture across an active (fold and thrust belt) margin. The Makran turbidite system is composed of a dense network of canyons, which cut into high relief accreted ridges and intra‐slope piggyback basins, forming at some locations connected and variably tortuous paths down complex slopes. Turbidite activity and trench filling rates are high even during the Holocene sea‐level highstand conditions. In particular, basin‐wide, sheet‐like thick mud turbidites, probably related to major mass wasting events of low recurrence time, drape the flat and unchannellized Oman abyssal plain. Longitudinal depth profiles show that the Makran canyons are highly disrupted by numerous thrust‐related large‐scale knickpoints (with gradients up to 20° and walls up to 500 m high). At the deformation front, the strong break of slope can lead to the formation of canyon‐mouth ‘plunge pools’ of variable shapes and sizes. The plunge pools observed in the western Makran are considerably larger than those previously described in sub‐surface successions; the first insights into their internal architecture and sedimentary processes are presented here. Large plunge pools in the western Makran are associated with large scoured areas at the slope break and enhanced sediment deposition downstream: high‐amplitude reflectors are observed inside the plunge pools, while their flanks are composed of thin‐bedded, fine‐grained turbidites deposited by the uppermost part of the turbidity flows. Thus, these architectural elements are associated with strong sediment segregation leading to specific trench‐fill mechanisms, as only the finer‐grained component of the flows is transferred to the abyssal plain. However, the Makran accretionary prism is characterized by strong along‐strike variability in tectonics and fluvial input distribution that might directly influence the turbidite system architecture (i.e. canyon entrenchment, plunge pool formation or channel development at canyon mouths), the sedimentary dynamics and the resulting sediment distribution. Channel formation in the abyssal plain and trench‐fill characteristics depend on the theoretical ‘equilibrium’ conditions of the feeder system, which is related closely to the balance between erosion rates and tectonic regime. Thus, the Makran turbidite system constitutes an excellent modern analogue for deep‐water sedimentary systems with structurally complex depocentres, in convergent margin settings.  相似文献   

广西丹池盆地泥盆系浊积岩和硅质岩的特征及构造意义     

廖宗廷  陈跃昆 《上海国土资源》1994,(3)

对广西丹池地区泥盆系浊积岩和硅质岩的沉积特征、岩石化学成分和形成机制的研究表明,它们是在受同生断裂控制的深水拗陷盆地中,由浊流和热水沉积而形成的沉积岩石。相同类型岩石的分布特征表现南盘江晚古生代沉积盆地呈浅海“台地”和深海“槽沟”相间排列的构造格局,其形成和演化与滇黔桂地体和云开地体的碰撞拼贴造山作用以及造山后地壳的蠕散拉伸作用有关。  相似文献   

南海海盆东南部大型深水浊积扇体系及其成因的构造控制          下载免费PDF全文

高红芳  钟和贤  孙美静  聂鑫  姜涛  黄文凯  杜文波  陈家乐 《中国地质》2020,47(5):1395-1406

运用近年来海洋地质调查工程获取的最新地质地球物理数据，在南海海盆东南部水深2000～3800 m区域，发现中中新世到第四纪多期大型浊积扇沉积体系，揭示了南海南部深海沉积作用及沉积演化过程。该浊积扇体系以沉积物波、水道充填、海底扇、块体流等沉积体为主，总体上由海盆东南部向海盆中央呈扇形推进，推进距离为150～ 260 km，从老到新规模和结构不断变化，蕴含了丰富的海平面变化信息。垂向上浊流沉积层层叠置发育，形成厚层的浊积砂体。海底水道十分发育，水道砂体底部呈“V”型展布，由南向北延伸，揭示出物源主要来自礼乐滩及北巴拉望区域。该浊积扇的形成明显受到构造控制，与中中新世以来礼乐滩—巴拉望岛的隆升和晚中新世以来的岩浆活动密不可分。浊流发育位置处于南海东南部陆缘和深海平原之间，是陆源物质由浅海输送到深海平原的重要机制，构成南海南部“源-汇”沉积体系的重要环节。  相似文献   

Overview of the MITI Nankai Trough Wells: A Milestone in the Evaluation of Methane Hydrate Resources   总被引：4，自引：0，他引：4  

Yoshihiro Tsuji    Hisashi Ishida    Masaru Nakamizu    Ryo Matsumoto  Satoshi Shimizu 《Resource Geology》2004,54(1):3-10

Abstract. Bottom-simulating reflectors suggestive of the presence of methane hydrates are widely distributed below the ocean floor around Japan. In late 1999, drilling of the MITI Nankai Trough wells was conducted to explore this potential methane hydrate resource and a Tertiary conventional structure. The wells are located in the Northwest Pacific Ocean off Central Japan at a water depth of 945 m. A total of six wells were drilled, including the main well, two pilot wells, and three post survey wells at intervals of 10–100 m. All wells except the first confirmed the occurrence of hydrates based on logging-while-drilling, wire-line logging and/or coring using a pressure and temperature coring system in addition to conventional methods. Based on the various well profiles, four methane hydrate-bearing sand-rich intervals in turbidite fan deposits were recognized. Methane hydrates fill the pore spaces in these deposits, reaching saturation of up to 80 % in some layers. The methane hydrate-bearing turbiditic sand layers are less than 1 m thick, with a total thickness of 12–14 m. The bottom depth of high hydrate concentration correlates well with the depth of the bottom-simulating reflector. Based on these exploration results, the Japanese government inaugurated a 16-year methane hydrate exploitation program in 2001.  相似文献   

山东东营牛庄洼陷沙三中亚段浊积砂体储层特征及影响因素   总被引：15，自引：3，他引：15  

饶孟余  钟建华  王海侨  郭泽清 《现代地质》2004,18(2):256-262

山东东营牛庄洼陷沙三中亚段浊积砂体储层以长石细砂岩、岩屑细砂岩及粉砂岩为主 ,结构成熟度及成分成熟度均较低。储层微观特征研究表明 ,砂体中发育了剩余原生粒间孔、粘土矿物杂基内的微孔隙、粒间溶孔、粒内溶孔及微裂缝等储集空间类型 ,孔隙结构以低渗细喉型为主 ,为物性较差的中低孔、低渗型储层。通过对储层物性影响因素的研究得出 ,岩石组构、沉积微相、成岩作用和异常超压的形成与分布是影响本区浊积砂体储层物性的主要因素。其中 ,碳酸盐胶结物、硅质胶结物及自生粘土矿物是致使储层物性变差的主要原因 ,沉积物中有机质的大量生烃以及粘土矿物在转化过程中所释放出的酸性水的溶解作用是产生次生孔隙的重要因素 ,而异常超压的存在、高的地温场及烃类的早期进入是部分原生孔隙和次生孔隙得以保存的重要条件。  相似文献   

浙西北二叠,三叠纪浊积岩系及其大地构造意义   总被引：4，自引：0，他引：4       下载免费PDF全文

何海清  陈海泓 《地质学报》1997,71(2):123-132,T001

对浙西北上二叠统长兴组，大隆组及下三叠统政棠组沉积特征，生物生态等的研究表明，长兴组，大隆组和政棠组为一套浊积岩系沉积，沉积背影为一向东南倾斜的被动大陆边缘，印支期造山作用使其发生了强烈的前陆褶皱－冲断变形，岩石地球化学分析结果表明在浊积岩沉积时期，推测可能存在的部分来来源于晚元古代岛弧和晚元古代造山带的物源。  相似文献