Changes in the source of sedimentary organic matter in the marginal seasediments of Eastern Hainan Island in response to human activities during thepast 200 years.
Changes in the source of sedimentary organic matter in the marginal seasediments of Eastern Hainan Island in response to human activities during thepast 200 years.
复制标题
近200年人类活动对海南岛东部边缘海沉积物沉积有机质来源的变化.
DOI：
10.1016/j.quaint.2016.07.007
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发表时间：
2017
影响因子：
2.2
通讯作者：
Xiaodong Liu
中科院分区：
文献类型：
--
作者：
Libin Wu;Pingqing Fu;Liqiang Xu;Yangyang Wei;Xin Zhou;Yeling Li;Xueying Wang;Yongli Zhou;Xiaodong Liu
海洋沉积物已被广泛用于重建环境变化和人类活动的记录。在南海万泉河河口和海南岛东部陆架采集了4个沉积物柱样，分析了各子样的岩芯物理化学性质。根据210 Pb测年，最长的岩心记录最近200年，而其他三个剖面略年轻。结果表明，1950年以前，四个柱状样的TOC/TN比值和化石燃料校正的有机碳δ 13 C值相对稳定，表明沉积物的物质来源相对稳定。1950年以后，TOC/TN比值和有机碳δ 13 C值分别呈下降和上升趋势，表明海洋来源的物质比例增加，而主要由万泉河搬运的陆源物质比例减少。这与公元1950年以来海南岛工农业生产和生活用水等人类活动的增加导致万泉河径流量和输沙量明显减少的趋势相一致。因此，我们认为，在陆地上的环境变化记录的海洋沉积物的源物质的变化，从海岸和河口。
Marine sediments have been frequently used to reconstruct the records of environment change and human activities. We collected four sediment cores from Wanquan River estuary and the eastern continental shelf of Hainan Island in the South China Sea, and analyzed the down-core physical and chemical properties of sub-samples. Based on210Pb dating, the longest core had a record of the most recent 200 years, while the other three profiles were slightly younger. The results show that both the TOC/TN ratios and fossil fuel-corrected organic δ13C of marine sediments for all four cores remained relatively constant before 1950 AD, indicating relatively stable sedimentary material sources. However, after 1950 AD, the TOC/TN ratios and organic δ13C in all four sediment cores displayed decreasing and increasing trends, respectively, indicating that the proportion of marine-derived material increased, whereas the land-derived materials that were mainly transported by the Wanquan River decreased. This is consistent with the obvious decrease in runoff and sediment discharges of the Wanquan River due to the increase in human activities, including industrial and agricultural production, and domestic water use in Hainan Island since 1950 AD. Therefore, we suggest that environmental changes on the land were recorded by changes in the source material of marine sediments collected from coasts and estuaries.