东海陆架北部泥质区表层沉积物碳酸盐粒级分布与物源分析

Distribution of the Carbonate Clast Size and the Provenance Analyses of the Surface Sediments in the Northern East China Sea

对取自东海陆架北部表层沉积物及黄河、长江河道沉积物样品按 1/ 4Ф或 1/ 2Ф的间隔筛分 ,分别测定不同粒级中碳酸盐的含量 ,结果表明东海陆架表层沉积物碳酸盐含量都较高 ,且在砂、砾级中异常富集 ,碳酸盐颗粒分布具有分散、多峰的特点 ;黄河沉积物碳酸盐含量较高 ,主要分布于细粒级部分 ,并在细粒部分富集 ;长江沉积物碳酸盐含量明显低于黄河 ,分布较均匀 ,但是由于有淡水钙质生物碎屑的混入导致粗粒级中碳酸盐较为富集。依据沉积物中碳酸盐含量、分布及富集特征 ,结合沉积作用分析 ,表明济州岛西南泥质区沉积物为黄河、长江物质以及泥质区周边的再悬浮物质三部分的混合产物。

Surface sediments taken from the Northern East China Sea , the Yellow River and the Yangtze River were divided into many sub-sections with an interval of 1/4Ф or 1/2Ф by means of sieving method. Then, the content of carbonatse in each sub-section was analyzed. It indicates that: ① for the samples from the East China, the content of carbonatse is between 10% to 16%; carbonate clast is rich in the coarse section; the distribution of the carbonate clast appear dispersal with poly-mode; ② for the samples from the Yellow River, the content of carbonatse is a bit high; the carbonate clasts are mainly stored and accumulated in the fine-section (of which grain-size smaller than 0.045mm); ③ for the samples from Yangtze River, carbonate content is apparently lower than that in the samples from the Yellow River; the content of carbonatse in each sub-fraction is similar apart from some increases occurring in the coarse fraction because of the mixing of biogenic clast. The carbonate content, distribution and accumulation pattern of the sediments from the muddy center suggest that the sediments in this area be the mixing one of the Yellow River matter, Yangtze River matter and re-worked suspended matter adjacent to the mud area.