摘要
对于南海中部（118个表层沉积物样,水深82~4 420 m）、东部（106个表层沉积物样,水深700~4 508 m）海域的表层沉积物的粒度资料按小于200 m,200~2 000 m,大于2 000 m水深段对水深、平均粒径、黏土含量进行统计分析,结果表明从陆架到陆坡再到深海,平均粒径和黏土含量随水深增加呈非常有规律的变化;把大于2 000 m水深区域再细分为大于2 500 m,大于3 000 m,大于3 500 m,结果表明平均粒径和黏土含量随水深增加几乎无变化,在南海中部水深大于2 000 m海域平均粒径为3.39~3.54μm,黏土平均含量为54.91%~55.47%;在南海东部水深大于2 000 m海域平均粒径为3.25~3.37μm,黏土平均含量为53.91%~54.56%。研究表明2 000 m水深具有划分深海沉积物的指示意义。南海中部水深大于2 000 m海域黏土平均含量为55.19%,平均粒径为3.39μm;在南海东部水深大于2 000 m海域黏土平均含量为53.91%,平均粒径为3.37μm;在南海中部、东部水深大于2 000 m海域平均粒径均小于4μm,黏土平均含量均大于50%,表明深海沉积物粒度特征是平均粒径小于4μm和黏土平均含量大于50%。黏土含量是非生物组分的代表和划分深海沉积物类型的一个独立参数,钙质生物和硅质生物组分是另外两个独立参数。南海东部海域表层沉积物中55种元素总含量为47.50%,硅、铝、钛、钠、钾、磷、钙、镁、铁、锰十种主元素含量为47.03%,其他45种元素含量为0.47%,虽然沉积物来源复杂、成因不同,但沉积物化学主成分并不复杂,主要由前10种主元素和氧元素组成。沉积物主元素铝、钙、硅分别富集于黏土、钙质沉积、硅质沉积中。通过建立沉积物生源组分与碳酸钙、三氧化二铝、二氧化硅的量化关系,可把碳酸钙、生物二氧化硅作为钙质生物和硅质生物的两个替代参数。
The grain size and content of clay from surface sediments in accordance with water depth of less than 200 m,200~2 000 m and more than 2 000 m in the central South China Sea（118 surface sediment samples with water depth from 82 to 4 420 m） and eastern South China Sea（106 surface sediment samples with water depth from 700 to 4508m） were statistically analyzed.The results indicate that the average grain size and content of clay have distinctly regular changes with water depth;furthermore,no remarkable change with water depth is found when the water depth over 2 000 m is further subdivided into over 2 500 m,over 3 000 m and over 3 500 m.For the depth range of water over 2 000 m,the average grain size and content of clay in the sediment samples from the central South China Sea are 3.39~3.54 μm and 54.91%~55.47% respectively,which are slightly higher than those from the eastern South China Sea（3.25~3.37 μm and 53.91%~54.56%）.As a result,the water depth of 2 000 m has a significant indicator to classify deep sea sediment.The average content and grain size of clay for sediments in the central South China Sea in the depth range of water over 2 000 m are 55.19% and 3.39 μm,respectively.In the eastern South China Sea with water depth over 2 000 m,the content of clay is 53.91%,and the average grain size is 3.37 μm.In general,the average grain size of surface sediments is less than 4 μm,while the average content of clay is higher than 50% in both central and eastern South China Sea with water depth over 2 000 m.The clay content is an independent index representative for abiotic components,and has been adopted to classify deep-sea sediment combined with calcareous and siliceous components.55 elements in the sediment samples from the eastern South China Sea were also detected,accounting for about 47.50% of the total content.Among them,the content for the main elements of silicon,aluminium,titanium,sodium,potassium,phosphorus,calcium,magnesium,iron and manganese is 47.03%,while only 0.47% is measured in associat
出处
《海洋学报》
CAS
CSCD
北大核心
2010年第6期118-129,共12页
基金
国家科学技术部科技基础性工作专项项目--深海沉积物分类与命名(2006FY220400)
"九○八"专项(908-02-05-03)
关键词
深海沉积物分类
水深
平均粒径
黏土含量
参数指标
主成分分析
classification of sediment in deep sea
water depth
average grain size
content of clay
indices
principal component analysis
