大九湖泥炭地距今16000年以来Hg沉积记录及影响因子

发布时间：2018-03-27 06:11

本文选题：Hg沉积　切入点：影响因子　出处：《中国环境科学》2017年03期

【摘要】：神农架大九湖盆地距今16000年以来的泥炭沉积被用来分析Hg含量变化及其主要影响因子.基于剖面Ti、Al、Sc、Rb、Sr、Pb、Zn等元素含量和δ13C、腐殖化度等指标,主成分分析和逐步回归分析揭示泥炭剖面Hg含量变化主要受大气降尘、地表径流作用下的矿物质输入、大气降水、泥炭分解程度等因子影响.根据各因子影响Hg含量的强度随年代(深度)变化以及剖面Hg含量变化,距今16000年以来大九湖泥炭剖面的Hg记录可以分为6个阶段.在阶段Ⅰ(16.0~15.6cal kyr BP),Hg含量低值源于大气降尘减少和泥炭分解程度降低;第Ⅱ阶段(15.6~14.2cal kyr BP)大气降水增加以及陆地生物量增多、陆源有机物输入增多,导致Hg含量升高;阶段Ⅲ(14.2~11.3cal kyr BP)Younger Dryas时期(YD,12.3~11.3cal kyr BP),因大气降尘增多,泥炭分解程度增加,Hg含量较YD之前升高;第Ⅳ阶段(11.3~4.3cal kyr BP),各因子作用波动明显,Hg含量整体处于高值段;在第Ⅴ阶段(4.3~3.1cal kyr BP)气候转干,大气降尘也较低,Hg含量出现明显的降低.第Ⅵ阶段(3.1cal kyr BP以来)表现出大气降尘的逐渐增加和整体减少的矿物质输入,反映降水减少以及逐渐增强的人类活动影响,Hg含量则持续升高.
[Abstract]:The Shennongjia Lake Basin since nine peat deposits in 16000 years were used to analyze the change of the content of Hg and its main influencing factors. Based on the profile of Ti, Al, Sc, Rb, Sr, Pb, Zn contents and 13C values, humification index, principal component analysis and stepwise regression analysis revealed the changes of Hg content of peat profile by atmospheric dust, surface runoff under the action of mineral inputs, atmospheric precipitation, peat decomposition degree factors. According to the effect of Hg content of each factor increases with the strength of the time (depth) change and the change of the content of Hg profile, 16000 years ago since the big nine Lake peat section Hg records can be divided into 6 stages. In stage I (16.0~15.6cal kyr BP), Hg content was lower due to the atmospheric dust reduction and peat decomposition degree decreased; the second stage (15.6~14.2cal kyr BP) precipitation increased and terrestrial biomass increased, terrigenous organic matter input increased, resulting in Hg Increased; stage III (14.2~11.3cal kyr BP) Younger Dryas (YD kyr BP, 12.3~11.3cal period), because of atmospheric dust increased, peat decomposition degree increased, the Hg content was increased before YD; phase IV (11.3~4.3cal kyr BP), the factor of obvious fluctuations in the overall Hg content in the high value period; stage V (4.3~3.1cal kyr BP) dry climate, atmospheric dust is low, the content of Hg obviously decreased. The sixth stage (3.1cal kyr BP) showed dustfall increased gradually and the overall reduction of mineral input, reflect the influence of human activities and precipitation decreased gradually, Hg content continued increased.

【作者单位】：皖西学院环境与旅游学院;南京大学地理与海洋科学学院;滁州学院地理信息与旅游学院;
【基金】：国家自然科学基金资助项目(41371202,40701190) 安徽省高校自然科学重点项目(KJ2011A274)
【分类号】：X142

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