【摘要】 <正> 长江口外的东海大陆架,是世界上最宽广的大陆架之一。对其沉积物现代沉积速率的测定,是研究该河口-陆架区沉积动力学的基本问题之一。迄今已发表了用²¹⁰pb放射性同位素测年法、BHC测年法等方法研究本陆架区现代沉积速率和沉积作用的论文报告。本文据1980—1981年间,中美两国海洋科学家联合对长江口-东海陆架区沉积动力学进行调查所取得的资料,报道了该区岩芯柱样DDT含量的空间分布,并试用DDT测年法估算了此陆架区的现代沉积速率。本文还着重对该海域的现代沉积作用强度,以及水中悬浮物质移除DDT污染物的能力进行了定量的探讨。更多还原

【Abstract】 The profile of DDTs was determined in sediment cores taken in the Chang Jiang Estuary-Donghai Sea Continental Shelf during China-US Joint Study in 1980-1981. The sedimentation rate was calculated from the depth consecutively containing DDTs in the cores after correction of biological disturbance. It was found that the sedimentation rates at the stations G8103, G8140, G8126, G8133 and G8i38 were 1.3, 3.4,≥2.3, 0.92 and 0.46cm/a respectively, which were in good agreement with those of Pb-210 and BHC dating. The depositing flux at the five stations was estimated to be 0.35-3.1g/cm~2.a and the removal of DDTs by suspended matters, 6.13-35.2ng/g. Though the deposition was much higher in the inner than in the outer shelf, the removal of DDTs by unit weight of suspensate was much lower in the inner shelf, probably implying the influence of particle size, organic content, residual time in water column and the turbidity.更多还原