我国参加大洋钻探的近十年回顾与展望     

汪品先 《地球科学进展》2014,29(3):322-326

1999年南海首次大洋钻探,有力促进了中国的深海研究,使中国进入了国际深海研究的前沿。15年后第二次南海大洋钻探的实施,标志着中国在该国际计划中作用的加强。回顾了参加IODP 10年(2003—2013年)来深海研究的进展,并展望未来,讨论中国大洋钻探在新10年IODP(2013—2023年)中的打算。中国大洋钻探提出了分3步走的发展计划:第一步争取再实现1~2次"互补性(CPP)"大洋钻探航次;第二步学习欧盟,争取也成为IODP的"钻探平台提供者";第三步和国际科技界合作,建造新一代的中国大洋钻探船。  相似文献   

On how thin submarine flows transported large volumes of sand for hundreds of kilometres across a flat basin plain without eroding the sea floor     

Christopher J. Stevenson  Peter J. Talling  Esther J. Sumner  Douglas G. Masson  Micheal Frenz  Russell B. Wynn 《Sedimentology》2014,61(7):1982-2019

Submarine gravity currents, especially long run‐out flows that reach the deep ocean, are exceptionally difficult to monitor in action, hence there is a need to reconstruct how these flows behave from their deposits. This study mapped five individual flow deposits (beds) across the Agadir Basin, offshore north‐west Africa. This is the only data set where bed shape, internal distribution of lithofacies, changes in grain size and sea floor gradient, bed volumes, flow thickness and depth of erosion into underlying hemipelagic mud are known for individual beds. Some flows were 30 to 120 m thick. However, flows with the highest fraction of sand were less than 5 to 14 m thick. Sand was most likely to be carried in the lower 5 to 7 m of these flows. Despite being relatively thin, one flow was capable of transporting very large volumes of sediment (ca 200 km³) for large distances across very flat sea floor. These observations show that these relatively thin flows could travel quickly enough on very low gradients (0·02° to 0·05°) to suspend sand several metres to tens of metres above the sea floor, and maintain those speeds for up to 250 km across the basin. Near uniform hemipelagic mud interval thickness between beds, and coccolith assemblages in the mud caps of beds, suggest that the flows did not erode significantly into the underlying sea floor mud. Simple calculations imply that some flows, especially in the proximal part of the basin, were powerful enough to have eroded hemipelagic mud if it was exposed to the flow. This suggests that the flows were depositional from the moment they arrived at a basin plain location, and that deposition shielded the underlying hemipelagic mud from erosion. Reproducing the field observations outlined in this exceptionally detailed field data set is a challenge for future experimental and numerical models.  相似文献   

塔中I号断裂带顺6井上奥陶统取芯段古生物群落演化及其古生态意义          下载免费PDF全文

蔡习尧  姜红霞 《沉积与特提斯地质》2014,34(3):12-19

本文研究了塔中I号断裂带西北端顺6井上奥陶统地层第一次取芯段的古生物群落,共划分出5种类型:分别为隐蓝细菌群落、海德菌-疑源类-四分珊瑚群落、四分珊瑚-海得菌群落、四分珊瑚-红藻类稀群落、棘皮类稀群落,各群落的生物组成均不同。确定礁群落有3种:隐蓝细菌群落、海德菌-疑源类-四分珊瑚群落和四分珊瑚-海得菌群落。隐蓝细菌群落发育于台地边缘较深水的灰泥丘,海德菌-疑源类-四分珊瑚和四分珊瑚-海德菌群落发育于台地边缘较浅水的生物礁,红藻类稀群落和棘皮类稀群落发育于台地边缘滩。灰泥丘、四分珊瑚骨架礁和海德菌障积礁地层溶蚀孔洞很发育,但是均被亮晶方解石充填。生屑砂屑滩中的溶孔具有残余孔隙,可能构成油气的储集空间。  相似文献   

Geochemistry and mineralogy of REY-rich mud in the eastern Indian Ocean     

《Journal of Asian Earth Sciences》2014

Deep-sea sediments in parts of the Pacific Ocean were recently found to contain remarkably high concentrations of rare-earth elements and yttrium (REY) of possible economic significance. Here we report similar REY-rich mud in a core section from Deep Sea Drilling Project Site 213 in the eastern Indian Ocean. The sediments consist mainly of siliceous ooze, with subordinate zeolitic clay that contains relatively high REY concentrations. The maximum and average total REY (ΣREY) contents of this material are 1113 and 629 ppm, respectively, which are comparable to those reported from the Pacific Ocean. The REY-rich mud at Site 213 shows enrichment in heavy rare-earth elements, negative Ce anomalies, and relatively low Fe₂O₃/ΣREY ratios, similar to those in the Pacific Ocean. In addition, the major-element composition of the Indian Ocean REY-rich mud indicates slight enrichment in lithogenic components, which probably reflects a contribution from southern African eolian dust. A volcaniclastic component from neighboring mid-ocean ridges or intraplate volcanoes is also apparent. Elemental compositions and X-ray diffraction patterns for bulk sediment, and microscopic observation and elemental mapping of a polished thin section, demonstrate the presence of phillipsite and biogenic apatite, such as fish debris, in the REY-rich mud. The strong correlation between total REY content and apatite abundance implies that apatite plays an important role as a host phase of REY in the present deep-sea sediment column. However, positive correlations between ΣREY and elements not present in apatite (e.g., Fe₂O₃, MnO, and TiO₂) imply that the REY-rich mud is not formed by a simple mixture of REY-enriched apatite and other components.  相似文献   

长江口外泥沙向南输运速率的变化探讨——以朱家尖岛附近海域为例     

吴晗  杨世伦  邓兵  张卫国  罗向欣  张朝阳 《上海国土资源》2014,(1):77-82

采用浅地层剖面测量、沉积物柱样测年和海图水深计算对比相结合的方法,探讨位于长江入海泥沙向南输送通道上的朱家尖岛海域的泥质沉积速率的历史变化,并通过水文泥沙测量和沉积物取样分析寻找长江入海泥沙向南输送的佐证。结果表明:朱家尖岛海域全新世海平面上升以来泥质沉积厚度为5~20m,相当于沉积速率0.06~0.25cm/yr;1840~1960年区域平均沉积速率为1.4cm/yr,近60年沉积速率仅为此前120年沉积速率的一半左右。据此推断:全新世后期以来该海域泥质沉积速率先后经历了一个长期(千年尺度)缓慢的增大阶段和一个短期(年代尺度)迅速的减小阶段,与长江流域人类活动和河口湾充填作用共同造成的入海泥沙通量的总体变化趋势相吻合。  相似文献   

自升式钻井平台中高压管道应力分析     

徐红梅  韩华伟  杜之富 《海洋工程》2013,31(5):112-116

高压泥浆系统是自升式钻井平台中的重要系统,对维持生产作业、保证平台的安全具有极为重要的意义。作为一个高性能,高应力系统,对高压泥浆系统进行应力分析以便对管线系统的布置、支吊架位置和结构进行评估是很有必要的。鉴于此,从分析理论、参考标准、分析工具和校核工况组合等多个方面进行探讨,计算该高压泥浆系统的一次应力和二次应力,法兰的强度以及模态分析,得到合理的管路布置,探索出自升式钻井平台中高压泥浆系统应力分析的可行方法。  相似文献   

东海近岸泥质区柱状沉积物的百年内沉积粒度变化及其影响因素   总被引：3，自引：0，他引：3  

程芳晋  俞志明  宋秀贤 《海洋科学》2013,37(10):58-64

通过对东海近岸泥质区ZC13 和ZA3 柱状沉积物的²¹⁰Pb 同位素测年和粒度分析, 分别得到了两柱状沉积物的沉积速率以及粒度特征。结果显示: ZC13 和ZA3 柱状沉积物低端对应的沉积年代分别为55 a(1955～2009 年)和140 a(1871～2010 年), 平均沉积速率为0.89 cm/a 和0.82 cm/a。ZC13 柱状沉积物以砂质粉砂为主; ZA3 柱状沉积物由顶部至100 cm 粒度组分及相关参数变化稳定, 岩性上表现为较细的黏土质粉砂, 显示较为稳定的沉积环境; 100 cm 以下岩性总体上表现为较粗的粉砂质砂, 粒度参数变化较大, 表明沉积环境受到一定的扰动。研究认为, 粒度随年代的变化受沉积物来源及沉积动力的影响。这些研究结果为研究东海近岸海域环境演变提供了研究依据。  相似文献   

Research on rotating speed’s influence on performance of Deep-Sea lifting motor pump based on DEM-CFD     

Yuan-wen Li  Shao-jun Liu 《Marine Georesources & Geotechnology》2013,31(8):979-988

Abstract

Metal minerals in deep sea are considered to be the most important mineral resources in the 21st century. With the development of science and technology, deep-sea mining has gained more and more attention, and the pipeline lifting method is the most promising for mining. It is particularly important to use the pump as a key component in the pipeline upgrading. In this paper, the DEM–CFD method is used to study the solid–liquid two-phase fluid flow in the Deep-Sea lifting motor pump. Data about the distribution of pressure on the suction surface and pressure surface as well as the distribution of particles in the pump under different rotation speed can be obtained. Tests verify the efficiency and head of the pump by numerical simulation. It provides a theoretical method for the study of solid–liquid two-phase fluid flow in deep-sea mining.  相似文献   

东沙海区泥火山调查进展*     

阎贫  王彦林  于俊辉  罗伟  刘兴健  靳永斌  李鹏春  刘杰  钟广见  易海 《热带海洋学报》2021,40(3):34-43

泥火山是地球运动和深部含流体物质向表层迁移的一种重要形式, 其喷溢及喷出物对认识地质动力、地层岩性和资源环境具有重要的意义。东沙海区新生界薄(~1km), 中生界厚(>5km), 是南海最典型的中生代沉积区和油气勘探待突破区。区内有众多的海山海丘, 过去都被推测为不利于油气成藏的岩浆火山。但近年来针对这些海山进行的调查发现了大量海底地层底辟形变与断裂、流体充注空白反射带和喷溢释放结构。通过浅表层取样采获了丰富的自生碳酸盐岩结核及深水珊瑚、海绵等生物, 表明众多海山、海丘具有明显的泥火山活动特征。东沙泥火山的发现表明区内具有良好的油气生成和运移条件, 为勘探源于中生界的油气和水合物提供了重要线索; 而大量深水珊瑚和海绵的出现指示东沙泥火山区可能是深水珊瑚礁、海绵礁发育区, 为研究油气泄漏、化养生物和环境三者的关系提供了重要的研究对象。  相似文献   

晚期泥底辟控制作用导致神狐海域SH5钻位未获水合物的分析   总被引：1，自引：0，他引：1  

王力峰  沙志彬  梁金强  陆敬安 《现代地质》2010,24(3)

海底泥底辟构造与天然气水合物成藏关系密切,泥底辟既能为水合物提供充分的气源物质,同时又能促使地层温度场改变进而影响水合物成藏稳定性。南海北部神狐海域SH5站位虽然BSR明显,但钻探证实不存在天然气水合物。该钻位温度剖面异常高,温度场上移,同时在其下伏地层中发现泥底辟构造和裂隙通道。根据上述事实并结合泥底辟发育各个阶段中的特点,认为泥底辟构造对天然气水合物成藏具有控制作用。泥底辟发育早期和中期阶段,低热导率和低热量有机气体有利于天然气水合物生成;而在晚期阶段,高热量液体上侵稳定带底界,导致水合物分解迁移。SH5站位很可能由于受到处于晚期阶段的泥底辟上侵而未能获取天然气水合物。  相似文献