摘要
对南海北部湾东部海域61个站位表层沉积物的常量元素分析结果表明,研究区沉积物中的常量元素以SiO2、Al2O3和CaO含量最高,平均含量分别为61.83%、11.18%和5.32%,其中SiO2、Al2O3代表了陆源碎屑组分,CaO代表了生物碎屑组分。沉积物中常量元素的含量与沉积物类型密切相关,表明元素的丰度受沉积物粒度控制明显;而元素较低的富集系数,指示沉积物中的碎屑物质主要为地壳来源。元素相关分析和R型因子分析表明,沉积作用、粒度效应、海洋生物作用和自生作用等,对沉积物中常量元素的分布起着主要控制作用。在因子分析基础上,应用Q型聚类法并综合元素空间分布规律和富集特征,把研究区分为六个地球化学分区:Ⅰ区沉积物主要来源于北部湾北部的河流输砂和近岸侵蚀物;Ⅱ区为琼州海峡东侧来砂、昌化江以及红河等其他河流输砂以及北部湾周边近岸侵蚀物的混合沉积;Ⅲ区主要为红河输砂;Ⅳ区沉积物主要来源于海南岛西部和南部近岸侵蚀物,另外海洋生物活动和自生作用也是该区沉积物的重要物质来源;Ⅴ区和Ⅵ区为北部湾湾内沉积物与外海沉积物共同作用下的混合沉积,其中Ⅵ区部分海域的沉积物受到自生作用影响。
61 surface sediment samples were taken from the eastern Beibu gulf to analyze their major elements and hence to study geochemical characteristics and sediment source. The result showed that SiO2, A1203 and CaO are the main chemical compositions in the surface sediments, with average Contents 61.83% 、11.18% and 5.32% respectively. The close correlation between the contents of major elements and the type of sediments indicates that the element abundance is controlled seriously by grain size of sediments, and the lower enrichment coefficient of the elements indicates the sediments are mainly from the earth＇ s crust. The correlation analysis and R--factor analysis revealed that the sedimentation, grain size effect, marine biogenic and authigenic process were the mainly controlling factors for the distribution of the major elements in the surface sediments. The study area was separated into six zones based on the clustering result and the distributions characteristics of the major elements. The sediments in the zone I were mainly from the river alluvium and coastal erosion in north of Beibu gulf; zone II was multiple sediment source area, the sediments from the east part Qiongzhou strait, together with the sediment of Changhua river, Red river and coastal erosion around, provided abundant material to this area; zone III, as the part of palaeodelta of Red river, mainly originated from the Red river; the sediments in zone IV are mainly from the coastal erosion of eastern and southern Hainan island, meanwhile, the marine biogenic process and authigenic mineral were also as the important sources for the sedi- ments; both V and VI zone are mixed deposits area, material from the inner and outer Beihu gulf controlled the composition of the sediments, meanwhile, the VI zone was partly influenced by authigenesis.
出处
《物探化探计算技术》
CAS
CSCD
2015年第4期522-531,共10页
Computing Techniques For Geophysical and Geochemical Exploration
基金
国土资源部海底矿产资源重点实验室开放基金项目(KLMMR-2013-A-14)
关键词
表层沉积物
地球化学
常量元素
物质来源
北部湾
surface sediments
geochemistry
major elements
provenance
the Beibu gulf
