全新世巢湖沉积记录及其环境变化意义

根据巢湖全新世沉积地层对比及对ACN钻孔沉积物的测年、粒度、营养元素含量分析,认为巢湖在全新世中经历了频繁的河流、湖泊交互作用,是一个受河流影响十分显著的沿江湖泊。中全新世以来,巢湖共发生三次显著的湖泊收缩过程,分别是在沉积纪录的5 887~5 680 a B. P. 时,其后又再度扩张;2 239~2 126 a B. P.时,是在中国历史时期第二温暖期暖干气候条件下形成的,与其同期的河流相冲积层或淤积粘土,正是巢湖周边战国至汉代古文化遗址的基底物质,之后巢湖再度扩张,甚至导致汉代古城成为水下遗址;1 827 a B. P.以来,是巢湖现代淤积过程。

Sediment Records in Chaohu Lake and Its Significance on Environmental Change in Holocene

According to the comparison among the Holocene sedimentary piles,as well as an analysis of the age data,granularity and the content of the mineral nutrient of deposits in ACN drilling sample,it is thought that Chaohu Lake impacted by the river mightily is a typical lake along Changjiang River,which experienced frequent river-lake interaction in the Holocene Epoch.Since the Holocene metaphase,the area of Chaohu Lake has remarkably contracted thrice,whose records were kept in the deposits.These records show that there was a contractive process between 5887-5680 a B.P.and then its area expanded renewedly;the sequent contractive process between 2239-2126 a B. P.,which was formed under the climatic conditions of the second period of warming in Chinese history(the contemporaneous fluvial facies alluvium and warp clay is no other than the basement matter of the site of ancient culture in Chaohu Lake and its surroundings during the period between the Warring States and Han Dynasty),following expansion once more that even makes the ancient city of the Han Dynasty into the underwatersite;the last contractive process since 1827 a B. P.,which has been a modern course of silting-up.