分析长江水下三角洲YD 0901孔的粒度、TOC(总有机碳)和TN(总氮),建立全新世以来高分辨率年代地层图(平均分辨率为20a).结果显示,"中全新世大暖期"(距今7ka~6ka)水下三角洲加速营造,同时闽浙泥质区开始缓慢形成.TOC和TN测试数据表明:在距今2.7ka左右,YD0901孔的TN含量逐渐增加,说明流域人类活动逐渐加剧;而TOC由于部分的成岩作用,含量并未明显增加.通过沉积相分析,得到最大海侵面的深度,为准确估算冰后期最大海侵以来水下三角洲沉积总量提供了可靠依据.
Based on grain size,total organic carbon(TOC) and total nitrogen(TN) analyses of core YD 0901 located in the subaqueous Yangtze River delta,the Holocene high-resolution chronostratigraphy was established.The study revealed that the subaqueous delta formed rapidly during 6~7 ka(the Middle of Holocene Warm Period).Meanwhile,the mud areas of Fujian and Zhejiang formed slowly.TOC and TN test data revealed that the content of TN increased around 2.7 kaB.P.,indicating the gradual increase of human activities in Yangtze River Basin.However,the content of TOC did not increase significantly because of the diagenesis.And the depth of maximum transgressive surface(34.22 m) witnessed the accurate estimation of the total amount of subaqueous delta since the post-glacial maximum transgression.