海坛岛海域表层沉积物中主量化学成分的地球化学

本文对海坛岛海域３３个表层沉积物中１０种化学成分的含量、含量变化和区域平面分布作了描述和探讨。化学成分中Ｃｏｒｇ、Ｎ、Ｐ、Ｆｅ、ＡＩ、Ｔｉ、Ｍｇ等元素的关性好,和粘土矿物关系密切,从陆源搬运入海;Ｃａ、碳酸盐和上述及粘土含量呈负相关,在富含生物介壳的粗粒沉积中富集;Ｍｎ主要赋存于陆源碎屑,而在砾砂中有自生Ｍｎ沉积。Ｑ型聚类分析的结果表明,调查区可分为３个地球化学分区,综合反映了沉积物的地球化学特征。     

顺序扫描ICP—AES法测定海洋沉积物中九种主要成分

用ICP—AES法测定海洋沉积物中铝、铁、钙、镁、钠、钾、钦、锰、磷等九种主要成分,方法简便,省时省力,测量精密度小于4％,可以满足海洋地球化学的要求。     

银洲湖港口群规划工程的潮流数值计算分析

介绍了银洲湖港群的自然环境，潮汐特征和工程规划概况，应用一维不恒定流计算方法分析港口群规划工程对沿线河道的潮位和涨落潮量变化的影响，用二维不稳定流计算方法分析港口群规划工程对港区及附近水域流态变化的影响。     

长江口沉积物中常量元素及有关形态物相定量分析研究

本文以熔融制样技术和数学校正分析方法的X射线荧光光谱实验手段,对长江口水域3个站位的10个常量元素进行定量分析.这10个常量元素分别是钠、镁、铝、硅、磷、钾、钙、钛、锰和铁,获得较好结果.分析的检出限达到10^-5左右;精密度用变差系数K表示,K<0.03826,因此具有较高精密度.最大分析相对误差是0.27%.此外本文还应用无标分析法的X射线衍射实验手段对同样3个站位样品进行形态物相定量分析.分析结果表明,长江口3个站位中沉积物主要成分是α-石英,其次是钠长石、高岭土、绿泥石、伊利石、方解石和蒙脱石等.分析结果与X射线荧光光谱元素定量分析结果基本一致,绝大部分物相定量分析误差小于15%.本文对于了解长江口存在的离子交换、吸附、解吸和絮凝等化学作用过程,均具有重要参考价值.     

海南岛崖州湾西部近海沉积环境特征

本文利用三亚赛德电厂工程可行性研究在崖州湾西部角头鼻附近海区所采集的地质资料，对该区的地貌、沉积物和沉积环境特征进行了论述。     

柘林湾表层沉积物重金属分布及污染初步评价

研究了柘林湾表层沉积物样品中7种重金属元素的质量分数及分布特征,并对其来源进行了分析。结果显示,调查海区Zn的平均质量分数为113.0μg/g±6.5μg/g、Cr为40.1μg/g±8.5μg/g、Mn为837.9μg/g±168.6μg/g、Cu为24.0μg/g±4.3μg/g、Pb为57.7μg/g±11.3μg/g、Ni为24.4μg/g±5.7μg/g、Fe为3.7%±0.4%。重金属主要来源于陆源风化产物,其质量分数反映了粤东地区的地质特点。分别以沉积物质量和香港环保署公布的标准,对柘林湾表层沉积物重金属污染进行了评估,结果表明:只有Pb在部分站位达到中度污染水平,其它重金属元素则只为轻度污染。     

南沙群岛海区94—10柱样浮游有孔虫碳氧同位素与古气候研究

通过对南沙群岛海区９４－１０柱样浮游有孔虫碳氧同位素组成,粒度组成及全岩样＾１４Ｃ测年的研究,发现南沙群岛海区在末次冰期结束后的转暖过程中发生了两次明显的气候回返事件,即事件和事件Ⅱ（约１０－８ｋａＢＰ）,其中事件Ⅰ可能为新仙女林事件;在末次冰期结束后的气候转暖过程中,东亚古季风演化具有不稳定性和突发性的特点。     

冲绳海槽岩心沉积物稀土元素特征及物源指示

通过对比研究了冲绳海槽南部、中部、北部岩心沉积物的稀土元素(REEs)组成和分异特征,揭示了冲绳海槽不同区域的物源差异。由于火山物质和周围河流携带的陆源物质贡献程度不同,各岩心沉积物REE组成存在显著差异。∑REE、∑LREE具由南至北递减的趋势,北部具相对更高的∑HREE,南部次之。LREEs与HREEs间的分馏程度,LREEs、HREEs内部分馏程度均由南至北依次减小。从粒度、微量元素和稀土特征参数的垂向变化来看,岩心S3物源相对单一,沉积环境随时间变化较小,主要受长江和台湾河流沉积物控制。岩心S10、S9沉积物来源更为复杂多样(特别是S9),沉积环境在时间尺度上发生了较大的变迁。岩心S10层位1主要受黄河和长江沉积物控制,层位2具黄河沉积物和火山物质混合的特征,岩心S9层位1是黄河沉积物和火山物质混合的结果,层位2主要受黄河沉积物控制。     

Smectite formation in metalliferous sediments near the East Pacific Rise at 13°N

A 43 cm long E271 sediment core collected near the East Pacific Rise(EPR) at 13°N were studied to investigate the origin of smectite for understanding better the geochemical behavior of hydrothermal material after deposition.E271 sediments are typical metalliferous sediments. After removal of organic matter, carbonate, biogenic opal,and Fe-Mn oxide by a series of chemical procedures, clay minerals(2 μm) were investigated by X-ray diffraction,chemical analysis and Si isotope analysis. Due to the influence of seafloor hydrothermal activity and close to continent, the sources of clay minerals are complex. Illite, chlorite and kaolinite are suggested to be transported from either North or Central America by rivers or winds, but smectite is authigenic. It is enriched in iron, and its contents are highest in clay minerals. Data show that smectite is most likely formed by the reaction of hydrothermal Fe-oxyhydroxide with silica and seawater in metalliferous sediments. The Si that participates in this reaction may be derived from siliceous microfossils(diatoms or radiolarians), hydrothermal fluids, or detrital mineral phases. And their δ30 Si values are higher than those of authigenic smectites, which implies that a Si isotope fractionation occurs during the formation because of the selective absorption of light Si isotopes onto Feoxyhydroxides. Sm/Fe mass ratios(a proxy for overall REE/Fe ratio) in E271 clay minerals are lower than those in metalliferous sediments, as well as distal hydrothermal plume particles and terrigenous clay minerals. This result suggests that some REE are lost during the smectite formation, perhaps because their large ionic radii of REE scavenged by Fe-oxyhydroxides preclude substitution in either tetrahedral or octahedral lattice sites of this mineral structure, which decreases the value of metalliferous sediments as a potential resource for REE.     

Molecular phylogenetic analysis of sulfate-reducing bacteria from deep sediment layers of the tropical West Pacific warm pool

1IntroductionThe tropical West Pacific warm pool(TWP-WP),which spans an area roughly between10°Nto10°S of the equator from Indonesia to the dateline,has the world’s warmest sea surface temperature ofbeing greater than29℃.With the increase of recog-niz…