【摘要】 利用2002年9月“东方红2号”调查船调查中获得的沉积物样品,定量研究了长江、老黄河口以及东海陆架沉积物中正构烷烃和无环类异戊二烯烷烃(姥鲛烷和植烷)两种天然示踪物,结果表明:(1)各采样站位样品的碳数范围为n-C14~n-C34,主要可分为陆源单峰、双峰和石油污染等3种类型。(2)长江口东南软泥区和浙江沿岸软泥区沉积物样品中高碳正构烷烃n-C27、n-C29和n-C31含量较高,奇碳优势显著,表明其来源以陆源高等植物输入占优势;相反,“东海冷涡”泥质区和黄海中南陆架区沉积物样品中的低碳正构烷烃n-C17、n-C18和n-C19含量较高,奇偶优势不明显,表明其来源主要以浮游生物和细菌为主。冲绳海槽泥质区沉积物样品中高碳与低碳正构烷烃的含量几乎相当,表明其来源为海洋低等生物和陆地高等植物共同输入,其中陆源物质是从东海陆架经底流搬运而来的。(3)有机质的堆积受控于物质供应和沉积环境两大因素。东海中陆架区沉积物中正构烷烃总量和有机碳含量为最低,这是由于台湾暖流的顶托,使黄河和长江两大物质扩散系统对该区的物质供应量减少,沉积速率低,潮流冲刷作用强,沉积物保存有机碳的能力较差;表层沉积物中正构烷烃及有机碳的最高值分别出现在浙江沿岸软泥区(E 5站)和冲绳海槽泥质区(P 4站);“东海冷涡”泥质区沉积环境最为适宜,但是陆源有机质供应则相对较少。更多还原

【Abstract】 Concentration and compositional feature of n-alkanes ,pristane and phytane in the modern sediments from the Changjiang Estuary,the old Huanghe River subaqueous delta and the East China Sea shelf are reported.The n-alkanes are in the rank of n-C₁₄～n-C₃₄,n-alkanes distribution patterns are characterized by four modes.Different distributions patterns and compositional feature of carbon molecules indicate that the input of terrigenous plant is the largest one in the sediments from the mud area of the southeast Changjiang Estuary and Zhejiang coast,however the marine biological origin,such as algae and bacteria,is more important in the middle continent shelf mud area.and combination of input from marine biological organisms and terrigenous plant is detected for the west slop of the Okinawa trough.The results also show that the lowest concentrations of（n-alkanes） and TOC occur in the sediment from the middle continent shelf area,resulting from the obstruction of the Taiwan Current Water （TCW）,which limits the organic matter input from the old Huanghe River subaqueous delta and the Changjiang River,as well as powerful hydrodynamic scouring on the sea floor.The sedimentation rate is slow and the sedimentary organic carbon cannot accumulate efficiently in this area.The highest concentrations of n-alkanes and TOC occur in the sediments from the mud area of the west slop of Okinawa trough,with a high organic carbon storage. The sedimentary environment in the mud area of the East China Sea is the most fitting for the preservation of sedimentary organic matter,but fewer terrigenous organic matters is input to this area,allowing moderate high contents of TOC and n-alkanes in the surface sediment.更多还原