【摘要】 通过对南海东北部(12°～22°N,116°～122°E)表层沉积中的浮游有孔虫、底栖有孔虫、钙质超微化石、硅质与钙质生物丰度和比值的定量分析以及碳酸盐含量的测定,发现碳酸盐含量、浮游有孔虫、钙质超微化石丰度以及钙质生物比值随水深的增大迅速减小,而底栖有孔虫占有孔虫全群的比值和硅质生物比值以及底栖有孔虫胶结质壳类的百分含量却随水深的增大迅速增加.研究表明,调查区内微体化石丰度和比值以及碳酸钙含量的高低,与碳酸盐溶跃面(lysocline)和碳酸盐补偿深度密切相关,碳酸盐溶跃面和碳酸盐补偿深度南、北还存在一定差异,碳酸盐溶跃面南部较北部深,南部在2600m上下,北部则在2200m上下;碳酸盐补偿深度也是南部的较深,南部为3 600 m上下,而北部在3 400 m上下。更多还原

【Abstract】 Based on the quantitative analyses of abundances of planktonic foraminifera, benthic foraminifera, calcareous nannofossil and ratios of calcareous and siliceous microorganisms as well as carbonate content in the surface sediment of the northeastern South China Sea, it has been found that the carbonate content, the abundance of planktonic foraminifera and calcareous nannofossil, and the ratio of calcareous microorganisms decrease rapidly while the ratio of the benthic foraminifera to the total foraminiferal fauna, ratio of siliceous microorganisms, and the percentage of the agglutinated tests in the benthic foraminiferal fauna increase rapidly with the increase of water depth. The results indicate that the microfossil abundance and ratio, and the carbonate content are closely related to the carbonate lysocline depth and CCD in the study area. In addition, the carbonate lysocline depth and the CCD are different between the southern and northern areas. The carbonate lysocline depth is deeper in the southern area(2 600 m) than in the northern one(2 200 m). The CCD is 3 600 m deep in the southern area, and 3 400 m deep in the northern one.更多还原