西南印度洋中脊表层沉积物中存在热液组分的地球化学证据

Hydrothermal materials in deep-sea sediments provide a robust tracer to the localized hydrothermal activity at mid-ocean ridges. Major, trace and rare earth element(REE) data for surface sediments collected from the ultraslow spreading Southwest Indian Ridge are presented to examine the existence of hydrothermal component.Biogenic carbonate oozes dominate all the sediment samples, with CaO content varying from 85.5% to 89.9% on a volatile-free basis. The leaching residue of bulk sediments by ~5% HCl is compositionally comparable to the Upper Continental Crust(UCC) in SiO_2, Al_2O_3, CaO, MgO, alkali elements(Rb, Cs) and high field strength elements(Nb, Ta, Zr, Hf, Ti). These detritus-hosted elements are inferred to be prominently derived from the Australian continent by means of eolian dust, while the contribution of local volcaniclastics is insignificant. In addition, the residual fraction shows a clear enrichment in Fe, Mn, and Ba compared with the UCC. Combining the positive Eu anomaly of residual fraction which is opposed to the UCC but the characteristic of hydrothermal fluids and associated precipitates occurred at mid-ocean ridges, the incorporation of localized hydrothermal component can be constrained. REE mixing calculations indicate that more than half REE within the residual fraction(~55%–60%) are derived from a hydrothermal component, which is inferred to be resulted from a diffuse fluid mineralization. The low-temperature diffuse flow may be widely distributed along the slow-ultraslow spreading ridges where crustal faults and fissures abound, and probably have a great mineralization potential.     

北极地区深海微生物研究进展及对策

对北极地区深海微生物研究进展进行了综述和展望分析,并提出强化我国北极深海微生物研究的对策,以期为相关研究和决策提供参考。综述表明北极深海微生物具有丰富的多样性,是数量巨大的遗传基因资源承载者,群落结构表现出显著的空间分布差异,在北极深海食物链中可能发挥着基础性作用。展望分析提出聚焦北极深海这一特殊的极端环境,开展微生物多样性和地理分布特征研究、新颖遗传生化功能挖掘以及多尺度生态系统下微生物与环境变化的研究具有重要意义和价值。建议我国顶层布局、构建北极深海微生物协同研究体系,提升专用配套仪器装备保障能力,全面推进相关研究工作。     

深海采矿扬矿泵导叶区域粗颗粒通过特性试验研究

在深海采矿系统中,海底矿石必须经过扬矿泵才能提升到海面船上,但矿石粒径较粗,容易在泵体中形成堵塞,尤其是在扬矿泵导叶区域,因此,研究粗粒在导叶中的运动特性对于保障系统安全工作具有重要意义。针对深海矿物粒径较大的特点,设计并制作了具有宽流道的扬矿泵流道模型,安装于管道输送试验系统。利用高速摄像机对扬矿泵导叶内粗颗粒运动特性进行了记录,并对其运动轨迹、碰撞情况以及颗粒速度等信息进行了分析。结果表明:颗粒在通过导叶区域时,运动轨迹与水流流向基本一致;颗粒与导叶发生碰撞位置主要集中于导叶背面入口处、导叶压力面中部和导叶背面出口处;颗粒粒径越小,跟随性越好,碰撞次数越少。试验结果可为扬矿电泵设计提供参考。     

UML在深海集矿机远程监控系统中应用研究

分析了UML（unified modeling language）建模方法在信息建模中的优点,具体研究了UML建模方法在深海集矿机远程监控系统建模中的应用;针对深海集矿机远程监控系统的工艺流程,采用UML中的用例图、活动图和序列图等描述远程监控系统的需求、分析和设计阶段的信息系统模型;并对深海集矿机远程监控系统进行建模,使系统模型更通用、更易理解,增强了系统模型的重用性和互操作性。以Rational Rose 2002为工具来描述UML方法的建模过程,开发了深海集矿机远程监控系统,在海洋采矿系统的模型机上试验运行情况良好。     

Phylogenetic analysis of bacterial community in deep-sea sediment from the western Pacific “warm pool”

A depth profile of bacterial community structure in one deep-sea sediment core of the western Pacific ＂warm pool＂ （WP） was investigated and compared with that in a sediment sample from the eastern Pacific （EP） by phylogenetic analysis of 16S rDNA fragments. Five bacterial 16S rDNA clone libraries were constructed, and 133 clones with different restriction fragment length polymorphism （RFLP） patterns were sequenced. A phylogenetic analysis of these sequences revealed that the bacterial diversity in a sample from the WP was more abundant than that in the EP sample. The bacterial population in the sediment core of WP was composed of eight major lineages of the domain bacteria. Among them the γ-Proteobacteria was the predominant and most diverse group in each section of WP sediment core, followed by the α-Proteobacteria. The genus Colwellia belonging to γ-Proteobacteria was predominant in this sample. The shift of bacterial communities among different sections of the WP sediment core was δ-, ε-Proteobacteria, and Cytopahga-Flexibacteria-Bacteroides （CFB） group. The ratios between them in the bacterial communities all showed inversely proportional to the depth of sediment. The sequences related to sulphate reducing bacteria （SRB） were detected in every section. The bacterial community structure in this sediment core might be related to the environmental characteristics of the surface seawater of the western Pacific WP.     

南中国海深水L区火山发育及地震反射特征研究

海洋石油天然气勘探面临最大的困难是高成本、高风险、高技术,因此,对地球物理工作者及地球物理技术提出了更高的要求.在对前期钻井资料分析了解的基础上,通过对工区内地震资料进行分析研究,同时对火山岩的基本地球物理响应特征进行分析归类,识别并归纳出该工区内四种类型的火山发育模式,建立起工区内四种火山岩发育类型的地震响应特征规律.这一规律将有助于研究南中国海深水区地震反射异常区的分析论证,有助于揭示不同时期地震异常体性质,为该地区的石油天然气勘探工作提供更为准确的资料.     

西太平洋多金属结核区表层沉积物细菌群落结构及其对沉积扰动的响应

本文基于大洋第48航次在西太平洋马尔库斯 威克海山多金属结核区采集的6个表层沉积物样品的高通量测序结果,开展底栖细菌群落结构调查,共获得253012条序列,分属于41个门、85个纲、189个目、261个科和322个属。其中,变形菌纲(Proteobacteria)为优势类群,分为γ 、α 和δ 三个亚群,分别占总序列条数的24.76%、20.21%和6.48%。绿弯菌门(Chloroflexi)、酸杆菌门(Acidobacteria)、芽单胞菌门(Gemmatimonadetes)、浮霉菌门(Planctomycetes)、放线菌门(Actinobacteria)、拟杆菌门(Bacteroidetes)及硝化螺旋菌门(Nitrospirae)等类群的序列数和属种较丰富。对序列条数大于1%的OTU(operational taxonomic units)分析,共获得优势菌群23个目,包含6个优势科,10个优势属,其中,铁锰功能细菌占10.20%,主要来自交替单胞菌属(Alteromonas)(6.90%)、假交替单胞菌属(Pseudoalteromonas)(1.80%)和希瓦氏菌属(Shewanella)(1.00%)等,另外还存在参与氮和硫元素循环的种属。PICRUSt功能预测分析显示结核区细菌主要涉及信号转导、蛋白转运、原核生物固碳、群体感应、能量转换、氨基酸和嘧啶代谢等功能。BC1826站位与其他站位相比,细菌多样性较低。结合沉积柱粒度分析结果,推测BC1826站位微生物群落结构的差异与沉积扰动有关,两者具有一定的响应关系。与已有研究成果汇总对比发现,西太平洋结核区与东太平洋结核区的细菌群落组成结构有较大差异。     

Pollen analyses off Senegal: Evolution of the coastal palaeoenvironment during the last deglaciation

Pollen and dinoflagellate cysts from marine sediments in core A180-48 (15°19′N, 18°06′W; 2450 m water depth; 530 cm length) are used to reconstruct palaeoenvironmental conditions of nearshore tropical west Africa during the last deglaciation. High concentrations and influxes of pollen and dinoflagellate cysts between 11 000 and 10 000 yr BP are interpreted as reflecting an increase in continental trade-wind circulation and related coastal upwelling at 15°N latitude. The sea-surface temperature difference between glacial and interglacial times was not as strong as previously suggested. Together with local (fresh) ground-water input, this smaller temperature difference may explain the persistence of the Rhizophora mangrove and Guinean gallery forests near the shore until their massive extension during the early Holocene humid maximum around 9500 yr BP. Pollen data from the core are compared with data from Rosilda N110-Z, from the continental shelf at the same latitude.     

中国多金属结核西示范区的结核小尺度分布特征

利用在中国多金属结核西示范区加密调查中获取的海底视像资料,通过水下定位数据处理和结核覆盖率计算,并结合多波束地形测量数据,从结核覆盖率分布角度对多金属结核的小尺度分布特征进行研究。研究结果表明:多金属结核分布与地形有一定的对应关系,在地形平缓区域,结核覆盖率变化较平缓,而在某些地形陡峭区域,由于块状结壳的形成,结核/结壳覆盖率出现明显的跃升;西示范区为结核高覆盖率分布区,结核覆盖率沿东西方向变化不大,由北向南呈增高趋势;地形坡度对结核分布有明显的影响,在区内0°~3.6°的坡度范围内,坡度越大,结核覆盖率越高。