摘要
利用X射线衍射法(XRD)对南海12个海底表层沉积物和20个悬浮物样品中粘土矿物组成和分布特征进行了综合分析。结果表明:(1)研究区的表层沉积物粘土矿物以伊利石为主,其次为绿泥石、高岭石、伊/蒙间层矿物以及蒙皂石;悬浮物粘土矿物是以绿泥石为主,其次为高岭石、蒙皂石、伊利石以及伊/蒙间层矿物。(2)粘土矿物的组成和分布特征主要受气候条件、物质来源、水动力条件及相互间稀释作用的制约。伊利石的含量随离岸距离和水深的增加呈增大趋势;高岭石则在近岸区特别是河口区富集;绿泥石在西部沿岸海区的含量较低,在东部岛弧和北部台湾岛附近海区的含量较高;蒙皂石与火山作用密切相关,在东部火山岛弧附近海区含量较高。(3)粘土沉积物的来源以河流输入为主,海洋自生和风尘搬运对该区的沉积影响不大。(4)深海悬浮物粘土矿物的组成变化能够很好地指示短尺度气候环境的变迁,伊利石的结晶程度对气候和环境变化反映灵敏,其随所处环境的压力增大而变差。
Based on XRD analysis, the clay mineral components and their assemblage feature of the surface sediments （12 samples） as well as the suspended particles （20 samples） in the South China Sea were studied. The surface sediments were collected by box sampler and the suspended particles were collected from 3 different water depth layers in NE2 station by sediment trapper during July 8, 1998 and April 30, 1999. The results show that the surface sediments are dominated by illite, followed by chlorite, kaolinite, illite/ smectite, and smectite; suspended particles collected in NE2 station are dominated by chlorite, followed by kaolinite, smectite, illite and illite/smectite. The composition and distribution of clay minerals are mainly controlled by climate, sediment sources, hydrodynamic condition, and dilution effect. Illite content increases with the water depth, kaolinite mainly occurres in the coastal area, particularly in estuaries. The eastern arc area has more chlorite than the western coast. Smectite which has close relationship with volcanism mainly occurred in eastern arc area. The clay minerals mainly transported by river, some were authigenic and some were carried by wind. The variation of different clay mineral phases is a good indicator of the change of climate and environment, particularly, the crystallinity of illite is climate and environment sensitive, with the increase of the water depth, the crystallinity of illite gets lower.
出处
《海洋学研究》
北大核心
2008年第1期58-64,共7页
Journal of Marine Sciences
基金
国家自然科学基金资助项目(40476050)
关键词
南海
粘土矿物
结晶度
环境意义
the South China Sea
clay minerals
crystallinity
environmental significance
