The spatial distribution of major and trace elements of surface sediments in the northeastern Beibu Gulf of the South China Sea

【摘要】 A multi-index analysis including grain size, major and trace elements is performed on the surface sediments from the northeastern Beibu Gulf to trace the sources of the sediments and to understand the controlling factors for elements distribution. The mean grain size exhibits a wide variation ranging from 0.09Φ to 8.05Φ with an average value of 5.33Φ. The average contents of major elements descend in an order of c（SiO₂）>c（Al₂O₃）>c（Fe₂O₃）>c（CaO）>c（MgO）>c（K₂O）>c（Na₂O）>c（TiO₂）>c（P₂O₅）>c（MnO）, while those of trace elements exhibit a descending order of c（Sr）>c（Rb）>c（V）>c（Zn）>c（Cr）>c（Pb）>c（Ni）>c（Cu）>c（As）. On the basis of elementary distribution characteristics and statistical analyses, the study area is divided into the four zones: Zone I is located in the northeastern coastal area of the gulf, which receives large amount of fluvial materials from local rivers in Guangxi and Guangdong, China, and the Qiongzhou Strait; Zone Ⅱ is located in the center of the study area, where surface sediments exhibits a multiple source; Zone Ⅲ is located in the Qiongzhou Strait, where surface sediments are dominated by materials from the Zhujiang River and Hainan; Zone IV is located in the southwest of the study area, where surface sediments are mainly originated from the Red River and Hainan. The statistical analyses of sediment geochemical characteristics reveal that the grain size, which is mainly influenced by hydrodynamics and mineral composition of terrigenous materials, is the leading factor controlling the elementary distribution.Meanwhile, impacts from anthropogenic activities and marine biogenic process will also be taken into consideration.更多还原

【Abstract】 A multi-index analysis including grain size, major and trace elements is performed on the surface sediments from the northeastern Beibu Gulf to trace the sources of the sediments and to understand the controlling factors for elements distribution. The mean grain size exhibits a wide variation ranging from 0.09Φ to 8.05Φ with an average value of 5.33Φ. The average contents of major elements descend in an order of c（SiO₂）>c（Al₂O₃）>c（Fe₂O₃）>c（CaO）>c（MgO）>c（K₂O）>c（Na₂O）>c（TiO₂）>c（P₂O₅）>c（MnO）, while those of trace elements exhibit a descending order of c（Sr）>c（Rb）>c（V）>c（Zn）>c（Cr）>c（Pb）>c（Ni）>c（Cu）>c（As）. On the basis of elementary distribution characteristics and statistical analyses, the study area is divided into the four zones: Zone I is located in the northeastern coastal area of the gulf, which receives large amount of fluvial materials from local rivers in Guangxi and Guangdong, China, and the Qiongzhou Strait; Zone Ⅱ is located in the center of the study area, where surface sediments exhibits a multiple source; Zone Ⅲ is located in the Qiongzhou Strait, where surface sediments are dominated by materials from the Zhujiang River and Hainan; Zone IV is located in the southwest of the study area, where surface sediments are mainly originated from the Red River and Hainan. The statistical analyses of sediment geochemical characteristics reveal that the grain size, which is mainly influenced by hydrodynamics and mineral composition of terrigenous materials, is the leading factor controlling the elementary distribution.Meanwhile, impacts from anthropogenic activities and marine biogenic process will also be taken into consideration.更多还原