北极东西伯利亚陆架沉积物物源:来自黏土矿物和化学元素的证据

本文对北极东西伯利亚陆架表层沉积物进行了粒度、黏土矿物以及常微量元素测定,阐述了粒度、黏土矿物和常微量元素的分布特征.利用因子分析与聚类分析划分了不同的沉积区,并探讨了各区沉积物的主要来源.结果表明,研究区可以划分为4个沉积区:(1)东西伯利亚海近岸河口区(Ⅰ区),沉积物以粉砂和砂质粉砂为主,TiO2、Zr、SiO2含...

Sediment provenance of the East Siberian Arctic Shelf:Evidence from clay minerals and chemical elements

Grain size,clay minerals and major and trace elements of surface sediment samples collected from the East Siberian Arctic Shelf are analyzed.Based on factor analysis and cluster analysis the study area is divided into four provinces,the main sediment sources of each province are discussed.The results show that province I covers the estuary area of the Kolyma River and the Indigirka River.The sediments are mainly composed of silt and sandy silt,and characterized by higher content of SiO₂,TiO₂,Zr and low content of other elements.The ratios of La/Th and Zr/Hf reach the maximum in the four sedimentary areas.Illite is dominant which accounting for 70%of the whole clay minerals.This area is strongly influenced by terrestrial sources from the Kolyma River and the Indigirka River.Province II is located in the middle of the East Siberian Sea,where the sediments are generally silt and mud.The content of MnO,Ba,and Ni are relatively higher.La/Th and Zr/Hf ratio are slightly lower than that in Province I.Clay minerals composition is similar to Province I.The sediments in this area are mainly fine-grained derived by rivers,which are also influenced by sea ice process.As the distance increasing offshore,the content of marine authigenic components begin to increase.Province III is located in the northern East Siberian Sea,and sediments there are mainly mud.Elements such as Al₂O₃,K₂O,V,Li reach the maximum value in this area.The La/Th and Rb/Th ratios are similar to those in the Province II.The content of illite is the lowest,semctite and kaolinite reach the maximum(>10%).Fine-grained sediments in this area are probably influenced by Atlantic waters and the Beaufort Gyre.Province IV is located in Chukchi Sea where the sediments consist of silt and sandy silt.Elements are characterized by higher contents of CaO,P2O₅.The ratios of Rb/Th,La/Th and Zr/Hf are the minimum values,the content of chlorite reach peak(>20%).Sediments in this area are significantly influenced by the Pacific inflow water.