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   

Multielement analysis of deep-sea sediments by inductively coupled plasma mass spectrometry     

Ning Xia  Zhaohui Wu  Dongfa Guo  De Yao 《中国海洋大学学报(英文版)》2008,7(2):137-144

Marine sediments were dissolved by HNO3-HF-HCIO4 in a sealed container at low pressure; I-IF was evaporated in an open container and salts were dissolved in HCl by heating, then transferred to 2% HNO3 solution. A total of 45 elements, including Li, Be, So, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Ga, Rb, Sr, Y, Zr, Nb, Mo, Cd, In, Sb, Cs, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, W, TI, Pb, Bi, Th and U, were measured by inductively coupled plasma mass spectrometry (ICP-MS). Condi-tions and sample experiments showed that this procedure defines a good experimental method which has the advantages of clear interference, easy operation and reliable results. The concentrations of the 45 elements could be used for resource exploration, envi-ronmental assessment and academic research.  相似文献   

基于康达效应的海底集矿装置流场与集矿特性试验研究     

胡经朝  赵国成  肖龙飞 《海洋工程》2022,40(5):132-138

海底集矿作为深海矿产资源开发的核心技术之一,直接影响到矿石采集效率和海底沉积物受扰动程度。基于康达效应的水力集矿装置因具有结构简单、可靠性高及对海床扰动小等优点,受到广泛关注。针对基于康达效应的水力集矿头模型进行3种类型的试验研究：1)利用粒子图像测速(PIV)技术测得集矿流场速度分布,试验发现流体质点在靠近凸曲面壁处流速和沿法线速度梯度较大,而远离凸曲面壁处则相反;2)通过高速摄像和图像处理获得球形矿粒运动轨迹和速度,试验发现了不同射流流速下5种典型矿粒运动形态;3)分析了射流流量对矿粒采集率的影响,试验得到了颗粒采集率关于射流流量的变化曲线,并根据变化特征划分为增长区、缓变区和跃升区。研究可为新式集矿装置的优化设计与性能分析提供参考。  相似文献   

Fluid-driven Hydrovolcanic Activity along Fracture Zones and near Seamounts: Evidence from Deep-sea Fe-rich Spherules,Central Indian Ocean Basin     

Ankeeta AMONKAR  Sridhar D. IYER  Elapavalooru V.S.S.K. BABU  Natarajan SHAILAJHA  Areef SARDAR  S. MANJU 《《地质学报》英文版》2021,95(5):1591-1603

An insight on occurrence of Fe-rich spherules from the Central Indian Ocean Basin (CIOB) provides an understanding of their distribution at a water depth of >5,000 m. In the present study, Fe-rich spherules are identified to occur in two different sediment types (i.e., siliceous and pelagic) and tectonic settings (i.e. near seamounts and fracture zones). These are single spheres or aggregates, of different sizes (63 to 390 μm) and show textural variability (smooth/quenched, brickwork, corkscrew, interlocking and dendritic). A comparative study based on physical morphology and chemical composition suggests a common mechanism of formation. The association of spherules with fracture zones (FZ) and seamounts signifies that morpho-tectonic features play an important role in fluid-driven hydrovolcanism. Based on the evidence and geologic conditions existing in the basin, we conclude that molten fuel-coolant interaction (MFCI) coupled with submarine hydrothermal exhalations could be an ideal mechanism for the formation of spherules and Fe-particles. The accretion of the spherules on the surface sediments could be a result of recent volcanic phenomena, while those occurring at different depths (280–355, and 460–475 cm-bsf) within the sediment core indicate two different episodes. The study provides a global implication in understanding fluid-driven magmatism in a deep-sea intraplate environment.  相似文献   

云南景洪上泥盆统南光组沉积环境新议     

俞赛赢  冯凡斌  刘桂春  聂小妹  陈光艳  张志斌  冯庆来 《地质通报》2013,32(10):1596-1600

云南景洪东南地区出露一套泥盆系,前人将其以粗粒碎屑岩为特征的部分命名为怕当组,根据腕足类化石鉴定其地质时代为中泥盆世;以碎屑岩、凝灰岩为特征的部分被命名为南光组,根据植物化石斜方薄皮木（Lepotophloeum rhombicum）划归晚泥盆世。对其沉积环境尚存在陆相和海陆交互相、浅海陆架相、半深海-深海相沉积环境的不同认识。本研究发现,粗粒碎屑岩层序中也发现有晚泥盆世标准植物化石斜方薄皮木（Lepotophloeum rhombicum）,并且粗粒碎屑岩层序位于剖面上部,南光组位于剖面下部,说明两者的地质时代均为晚泥盆世。故建议废除怕当组,将两者合并为上泥盆统南光组。南光组具有典型的鲍马序列特征,含有放射虫等海洋环境生物化石,属于深海浊流沉积层序。  相似文献   

天然气水合物钻探取样技术现状与研究          下载免费PDF全文

许俊良  任红 《探矿工程》2012,39(11):4-9

通过资料调研与研究,综合分析了国外深海天然气水合物钻探取样工具的结构原理、技术参数、作业过程、主要特点以及对设备的要求等。同时简要介绍了我国“十一五”期间取样装置的研制进展情况。  相似文献   

北大西洋IODP U1313站位早更新世深海沉积物陆源组分粒度特征及其环境意义^*          下载免费PDF全文

翟秋敏  郭志永  李磊  王海荣 《古地理学报》2012,14(2):261-268

北大西洋地区是全球环境变化研究的热点区域。对IODP（国际综合大洋钻探计划）北大西洋306航次U1313站位深海沉积物陆源组分的粒度分析发现,陆源组分主要由黏土(粒径小于4μm)和极细粉沙(4～8μm)两个粒级构成,以黏土为主,分选性较差。通过与钙质超微化石、有孔虫等生物化石资料和同位素测年等技术相结合,重建了古气候的变化情况：(1)2.415～1.897 Ma BP,气候呈周期性波动;(2)1.897～1.640 Ma BP,气候变化相对平缓;(3)1.640～1.471 Ma BP,气候波动剧烈且频繁。粒度指标所反映的几次粗颗粒增多事件与早更新世期间数次气候变冷事件的发生时间一致。1.6 Ma BP前后粒度参数的突然变化,可能与地球轨道参数的改变有关,进一步证实地球轨道参数作为气候系统外部驱动力的重要性。  相似文献   

深海稀软底质土宏观性能与显微结构分析     

马雯波  饶秋华  吴鸿云  郭帅成  李鹏 《岩土力学》2014,35(6):1641-1646

针对取样于太平洋C-C矿区的深海稀软底质土,采用激光粒度分析、液塑限联合测定、氮吸附、固结和直剪等方法对其开展物理和力学性能研究,并通过X射线衍射法和电镜法分析其矿物组成成分和微观结构。研究结果表明：深海稀软底质土为以粉粒为主的黏质土,具有高液限、高塑性,高比表面积、高固结系数、低压缩模量、低抗剪强度等特性,极易造成集矿机的沉陷和打滑。该土样的矿物成分主要由蒙脱石、石英、长石、云母、绿泥石和蛇纹石组成,显微结构为以粉粒和微生物碎片为主的片状链接结构和以黏土矿物为主的蜂窝状絮凝结构相互填充而成。深海稀软底质模拟土的配置原则应以矿物成分、粒径、含水率、比表面积和剪切强度为主,且综合考虑液限、塑限和显微结构。研究结果将为深海集矿机行走特性研究及其优化设计提供重要依据。  相似文献   

Turbidite Events Recorded in Deep-sea Core IR-GC1 off Western Sumatra: Evidence from Grain-size Distribution     

QIU Zhongyan  HAN Xiqiu  WANG Yejian 《《地质学报》英文版》2017,91(4):1448-1456

Sediment core IR-GC1, from the abyssal basin of the Indian Ocean off Sumatra, may provide important information on depositional events related to earthquakes and tsunamis. In this study, based on a combination of grain-size analysis with lithological studies and oxygen isotope stratigraphy, seven deep-sea turbidite layers were identified, corresponding to seven turbidity events that occurred at 128–130, 105–107, 98–100, 86–87, 50–53, 37–41 and 20–29 ka. The sediments of the turbidite deposits are characterized by coarse grain sizes, poor sorting, wide kurtosis, bimodal frequency distributions and clear depositional variations. Particle size grading is also an important signature of deep-sea turbidite deposits and can be used as an indicator to identify turbidite layers. Possible triggering mechanisms for the turbidite events include tsunamis, earthquakes, volcanic eruptions and sea-level changes.  相似文献   

西太平洋深海科学观测网的建设和运行     

汪嘉宁  王凡  张林林 《海洋与湖沼》2017,48(6):1471-1479

西太平洋科学观测网是由中国科学院海洋研究所自主建成的大洋观测网络。深海数据的连续获取和实时传输对海洋与气候预报和海洋环境安全保障意义重大,世界海洋大国纷纷致力于其关键技术和系统集成的攻关。在中科院战略性先导科技专项的资助下,中科院海洋所经过统筹安排和周密部署,3年多来先后组织西太平洋综合考察航次3次,成功布放和回收深海潜标73套次,建成了由16套深海潜标组成的我国西太平洋科学观测网并实现稳定运行,获取西太平洋代表性海域连续3年的温度、盐度和洋流等数据。在2016年航次中,中国科学院又攻克了潜标数据长周期稳定实时传输的海洋观测难题,实现了深海数据的"现场直播",截至2017年9月,深海数据已成功连续实时回传260余天。以此为标志,我国的大洋科学观测网建设实现了批量化、标准化和常态化。深海观测数据的长时间连续积累和实时化传输,将提升我国深海科学研究能力,加速我国海洋与气候预报业务系统建设步伐,满足海洋强国建设、"一带一路"倡议对海洋环境安全保障的重大需求。"十三五"时期,我国正全面推进深海进入、深海探测和深海开发的深海战略,深海科学观测网建设技术和潜标数据实时传输技术对我国深海探测能力的提升意义重大。  相似文献