摘要
为了深入认识珠江现代入海物质在粤西陆架随海流迁移扩散的路径和沉积中心,利用GaoCollins方法分析了粤西-琼东北近海1 515个站位的粒径趋势,并用210 Pb法测定了8支柱样的现代沉积速率。结果表明,在粤西沿岸流和南海暖流这两个相向海流的共同作用下,珠江口外珠江来源的泥质沉积物的主体被限制在-50m等深线以浅的内陆架。现代珠江入海物质能维持粤西陆架泥质沉积区0.1cm/a左右的现代沉积速率。在川山群岛至海陵岛一带和琼州海峡东侧泥质区,分别受岛屿阻挡和逆时针中尺度涡旋的影响,形成了现代沉积中心。在沉积物不同粒级的来源和搬运方式存在差异的地方,粒径趋势分析结果可能主要反映的是粗颗粒沉积物的运移趋势,而非细颗粒沉积物的运移方向。
To better understand the transport path and deposition center of Pearl River originated sediment on the shelf off western Guangdong coast,the grain size trend of 1 5 1 5 surface sediments were analyzed by using Gao-Collins method and the modern sedimentation rate of 8 core samples was measured based on 210 Pb method.The results show that outside the river mouth,the main part of muddy sediment provided by Pearl River was confined to inner shelf with water depth less than 50 m, due to the combined effects of two oppositely flowing current：the coastal current and the South China Sea warm current.A modern sedimentation rate of about 0.1 cm/a on western Guangdong muddy shelf can be maintained by Pearl River originated sediment.Two modern sedimentation centers exist,they are Chuanshan Islands-Hailing Island muddy zone and the muddy area lay east of Qiongzhou Strait, controlled by island blocking and a counter-clockwise mesoscale eddy,respectively.As the source and the way of transport of coarse and fine sediment may be different,the grain size trend result may mainly reflect the transport trend of coarse sediment but not the migrating direction of fine sediment.
出处
《吉林大学学报（地球科学版）》
EI
CAS
CSCD
北大核心
2014年第3期905-917,共13页
Journal of Jilin University：Earth Science Edition
基金
国家自然科学基金项目(41106046)
海洋公益性行业科研专项项目(201105003)
国家海洋局第二海洋研究所基本科研业务费项目(JG1109
JT1002)
关键词
珠江
源汇过程
现代沉积速率
粒径趋势
近海沉积物
Pearl River
source to sink
modern sedimentation rate
grain size trend
western Guangdong
northeastern Hainan
