粤西水东湾动力沉积环境分析  

ANALYSIS OF DYNAMIC DEPOSITIONAL ENVIRONMENT IN SHUIDONG BAY OF WESTERN GUANGDONG PROVINCE

作　　者：于吉涛[1] 陈子燊[1] 

机构地区：[1]中山大学地理科学与规划学院水资源与环境系,广州510275

出　　处：《海洋地质动态》2010年第5期34-38,共5页Marine Geology Letters

摘　　要：对粤西水东湾海底表层122个沉积物样品运用经验正交函数分解与沉积粒度参数等计算分析,提取的4个主要特征函数共占样品粒级分布总方差的96.4%,4个函数分别代表了极细砂、细砂、中砂和粗砂在近岸区的分布特征,其与沉积物样品粒度质量百分比分布符合良好。滨面坡沉积物主要由砂粒级物质组成,粒级参数MdΦ、QdΦ和SkΦ具有从海向岸、自东南向西北变化的总趋势。落潮三角洲沉积物较其邻近滨面斜坡有所粗化,分选从中部向两侧变好。海湾沉积物分布特征表明:①潮汐通道深槽受以落潮为主的涨落潮双向水流的往复分选;②落潮三角洲主要受波浪和海流冲刷分选;③上滨面受波浪变形破碎的扰动作用;④下滨面是动荡的近海水区,波浪对底质扰动小。In this paper we uses empiricial orthogonal function and sediments grain size paramaters to calculate and analyze 122 bed sediment samples which come from surficial layer of Shuidong Bay in western Guangdong Province and pick up four principal eigenfunctions,accounting for 96.4 percentage of the total samples variances of grain size distribution which represent distribution character of very fine sand,fine sand,middle sand and coaser sand on nearshore area,respectively.This result accords well with grain size weight percentage distribution of sediment samples.The sediments of shoreface ramp mainly consist of sand size materials and it exhibits changing trend of general grain size parameters（MDΦ、QDΦ and SKΦ） from sea to shore and from southeast to northwest.The sand grain-size of ebb delta becomes coarser than that of neighbored shore face,and sorting becomes better from the middle to both sides of the ebb delta.The sediment distribution of Shuidong Bay shows that（a） deep trough of tidal channel sustains to-and-fro sorting of bidirectional currents of flood and ebb tide,based on the principle of ebb tide;（b） ebb delta mainly suffers from scouring and sorting of wave and tide;（c） up-shoreface goes through turbulence of wave breaking due to wave transforming;（d） down-shoreface belongs to nearshore oscillatory water area and bottom materials are disturbed slightly by wave.

关 键 词：沉积物类型 沉积地貌单元 粒级参数 经验正交函数 

分 类 号：P736.213[天文地球—海洋地质]