山东—辽东半岛周边海域沉积物粒度特征对元素化学成分的制约

    CONSTRAINT OF SEDIMENT GRAIN-SIZE TO ELEMENT CHEMISTRY: A CASE FROM THE SHANDONG-LIAODONG PENINSULAS

    • 摘要: 为研究山东—辽东半岛周边海域沉积物粒度及沉积物类型对地球化学成分的控制作用,分析了该海域135个表层沉积物粒度和常微量元素组成。结果表明,研究区沉积物常微量元素组成与粒度关系密切:SiO2含量与平均粒径大致表现为负相关;Al2O3、Fe2O3、MgO、TiO2、Cr、V、Zn、Co、Ni、Cu与平均粒径大致表现为正相关;而CaO、K2O、MnO、Na2O、P2O5、Ba、Sr、Zr、Pb则与平均粒径没有明显的相关性。砂、粉砂质砂、砂质粉砂及粉砂4种沉积物类型中的元素分布也呈现明显的差异性,常量元素Mean(s)/Mean(t)值在粉砂质砂沉积物中最接近1;颗粒最粗的砂的变化趋势与粉砂质砂较为一致;较细颗粒的砂质粉砂和粉砂,Mean(s)/ Mean(t)值变化较大,除了SiO2和K2O之外,多数元素表现为>1。微量元素在较细颗粒的粉砂和砂质粉砂分布较为相似,表现为较大幅度的波动;而较粗颗粒的粉砂质砂和粉砂则变化较小,Mean(s)/Mean(t)值略<1。以研究区分布最普遍的砂质粉砂中SiO2/TiO2和Al2O3/TiO2为指标来研究现代河流入海物质的输运范围,揭示了黄河入海物质可以大范围运移至渤海中部(121.5°E),后沿山东半岛近岸一直输运至南黄海中部,而朝鲜半岛来源物质主要集中在123°E以东区域。

       

      Abstract: The grain-size and the major-minor element characteristics of 135 surface sediment samples from the sea area around the Shandong-Liaodong Peninsula are analyzed to study the control of grain-size and sediment types over geochemical composition. The results reveal that the major-minor element composition is closely related to sediment grain-size.The SiO2 content is negatively related to the average grain-size. Instead, Al2O3、Fe2O3、MgO、TiO2、Cr、V、Zn、Co、Ni、Cu are positively related to the average of grain-size. However,CaO、K2O、MnO、Na2O、P2O5、Ba、Sr、Zr、Pb do not show any obvious relation with the average grain-size. The element composition in the four kinds of sediments of sand, silty sand, sandy silt and silt are also different.TheMean(s)/Mean(t) values of major elements are close to 1 in silty sand and show similar trend in sand.TheMean(s)/Mean(t)values of sandy silt and silt change greatly and most of the values are greater than 1 expect for SiO2and K2O. The distribution of minor elements in the fine sediments of silt and sandy-silt is similar of which both show drastic great variations; the coarse sediments of sand and silty sand, however, have small changes and the values ofMean(s)/Mean(t) are less than 1.The SiO2/TiO2 and Al2O3/TiO2widely distributed sandy siltare used to indicate the transport distance in modern rivers. It reveals that materials from Yellow River can transport to middle of the Bohai Sea(121.5°E) and then to South Yellow Sea along the Shandong Peninsula, and the materials from the Korean Peninsula are deposited to the east of 123°E.

       

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