冲绳海槽中部热液区近海底水体及沉积物地球化学特征

发布时间：2018-01-17 13:38

本文关键词：冲绳海槽中部热液区近海底水体及沉积物地球化学特征　出处：《中国科学院研究生院(海洋研究所)》2016年硕士论文　论文类型：学位论文

【摘要】：本文通过搭载于无人遥控潜水器ROV上的多种原位实测传感器(甲烷传感器、二氧化碳传感器及CTD等),对冲绳海槽中部热液活动区Iheya North和CLAM区近海底水体相关特征进行了研究,首次分析了不同活跃程度的热液区喷口附近海水水体中溶解甲烷和二氧化碳的水体特征。同时,结合ROV上拍摄的视频资料和研究区水体温度分布特征,初步讨论了温度对热液区生物聚集的影响。此外,通过搭载于ROV上的浅表层Push Core取样器首次获取距离热液喷口仅35 m的热液区沉积物样品。通过分析得出近喷口热液沉积物独特的的地球化学特征。Iheya North热液区远离热液口(正常海水)的近海底水体中甲烷和二氧化碳气体浓度为0μmol/l和400 ppm。黑烟囱喷口附近甲烷和二氧化碳浓度达到最高值,分别为8μmol/l和12000 ppm。不过,在低温溢流区附近甲烷和二氧化碳浓度相比黑烟囱喷口区减小,保持在2μmol/l和4000 ppm左右。尽管如此,低温溢流区二氧化碳浓度亦是正常海水中二氧化碳浓度的10倍之多。CLAM热液区没有正在喷发的黑烟囱,仅在热液生物曾经大量聚集区检测到最高浓度为2200ppm的二氧化碳。该区二氧化碳浓度仅仅是Iheya North区二氧化碳浓度的六分之一。由于前人主要通过对热液流体性质展开相关研究,发现冲绳海槽热液区气体的富集特点。本文首次通过海底原位气体传感器对热液区周围海水水体中溶解气体浓度的检测验证了冲绳海槽热液喷口喷发大量甲烷和二氧化碳气体,并且高出传统气相色谱法检测浓度至少四个数量级。浅表层沉积物相关的地球化学特征表明,本次研究样品主要组分主要为SO3,ZnO和Fe2O3,与正常海底沉积物中以Al2O3,SiO2和CaO为主要成分的沉积物明显不同。此外,元素的相关分析表明锶、汞和银可以作为热液特征组分。一些微量元素如Cu,Pb,Zn,As,Sb,Hg,Se,Ag,Ba,Mo和Cd在近喷口热液沉积物中也高度富集。元素的因子分析进一步反映热液沉积物来源主要是热液源。锶同位素比值进一步表明Iheya North热液区具有较弱的沉积物/流体相互作用。
[Abstract]:In this paper, a variety of in-situ sensors (methane sensor, carbon dioxide sensor, CTD and so on) are carried on the unmanned remote control submersible (ROV). In this paper, the characteristics of Iheya North and CLAM near seafloor waters in the hydrothermal active zone of the Okinawa trough are studied. The characteristics of dissolved methane and carbon dioxide in seawater near nozzle of hydrothermal zone with different activity were analyzed for the first time. At the same time, combined with the video data taken on ROV and the characteristics of water temperature distribution in the study area. The effect of temperature on biological aggregation in hydrothermal region was discussed. For the first time, only 35 per cent of hydrothermal vents were obtained from the shallow surface Push Core sampler mounted on the ROV. Analysis of the unique geochemical characteristics of hydrothermal sediments near the vent. Iheya North hydrothermal zone away from hydrothermal orifice. The concentration of methane and carbon dioxide in the water near the sea floor is 0 渭 mol/l and 400ppm. The concentration of methane and carbon dioxide near the black chimney vent reaches its highest value. However, the concentration of methane and carbon dioxide near the low temperature overflow zone is smaller than that in the black chimney vent area. It was maintained at 2 渭 mol/l and 4 000 ppm. The concentration of carbon dioxide in the low temperature overflow area is 10 times higher than that in the normal seawater. There is no black chimney erupting in the clam hydrothermal region. The highest concentration of carbon dioxide has been detected in a large concentration of hydrothermal organisms only at 2200ppm. The concentration of carbon dioxide in this area is only Iheya. The concentration of carbon dioxide in North region is 1/6. Because of the previous studies on the properties of hydrothermal fluids. The characteristics of gas enrichment in the hydrothermal zone of the Okinawa trough have been found. In this paper, the concentration of dissolved gases in the seawater around the hydrothermal zone has been verified for the first time by the in situ gas sensor in the sea floor of the Okinawa trough. A large amount of methane and a large amount of methane are emitted from the hydrothermal vent of the Okinawa trough. Carbon dioxide gas. The geochemical characteristics of shallow surface sediments show that the main components of this study are so _ 3O _ 3 and Fe2O3. It is obviously different from the sediments with Al _ 2O _ 3-SiO _ 2 and CaO as the main components in the normal seabed sediments. In addition, the correlation analysis of the elements shows that strontium is the main component. Mercury and silver can be used as hydrothermal characteristic components. Mo and CD are also highly enriched in hydrothermal sediments near vents. Factor analysis of elements further indicates that hydrothermal sediments are mainly derived from hydrothermal sources. Strontium isotope ratios further indicate that Iheya is a major source of hydrothermal sediments. There is a weak sediment / fluid interaction in the North hydrothermal region.
【学位授予单位】：中国科学院研究生院(海洋研究所)
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：P736.4

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