摘要
对渤海三个典型海域 6个站位柱状沉积物自然粒度下的有机碳 (OC)进行了研究 ,探讨了有机碳的垂直分布特征及其氧化还原环境 (E0h,E0s,Fe3+/Fe2 +比值 )因素对渤海沉积物中有机碳的影响 .渤海自然粒度沉积物中的有机碳含量在 0 3 9— 0 86 %之间 ,一般在表层 次表层含量变化较剧烈 ,在下层变化较缓 .相关分析说明 ,在中层 ,一般沉积物的还原性相比表层有增强 ,氧化环境与还原环境共存 ,有机质被氧化 ,OC浓度变得趋于减小 ,Fe3+/Fe2 +也趋于减小 ,二者有明显的正相关 ;在下层 ,还原环境占据了主导地位 ,导致大量OC不能被氧化 ,就被保存了下来 ,而Fe3+/Fe2 +却明显减小 ,所以在下层OC Fe3+/Fe2 +呈较强的负相关 ;在表层又掺杂了生物化学与物理扰动等因素 ,使OC Fe3+/Fe2 +的相关性变得复杂 ,且不规律 .表层 次表层OC主要取决于物质来源和物理搅动 ,变化较复杂 ;中、下层主要受氧化还原环境影响 ,矿化作用明显 ,有机碳含量逐渐降低 ;下层除C3区和A区外 ,有机碳含量也逐步降低 .有机碳含量不同层次受不同的物质来源、沉积环境、氧化还原进程与不同的生物化学过程共同影响 .从C区的断面分布看 ,表层 次表层呈垂直叠层分布 ,主要是逐步垂直沉降沉积的结果 .2 5cm以下呈水平推进式梯度分布 。
Geochemical characteristics of organic carbon(OC)in the Bohai sea natural grain size core sediments were studied.The OC distributions(including vertical and section distributions)and the influence factors such as pH,E h,E s and Fe 3+/Fe 2+ are also discussed.The OC in different sediment layer is controlled by different factors such as terrestrial input,sediment redox environment,the progress of early diagnesis and biochemical process.OC is mainly controlled by terrestrial input and dynamical disturbance in surface/subsurface layer and is highly controlled by the redox environments in middle and bottom layer.From the OC section distributions,the OC in surface/subsurface layer present vertical variation with the result of gradual sediment settling.From 25cm to bottom it present horizontal grads distribution.This probably was caused by a special sediment accident at that time such as a deluge.
出处
《环境化学》
CAS
CSCD
北大核心
2003年第2期115-120,共6页
Environmental Chemistry
基金
中国科学院创新重大项目 (KZCX1 SW 0 1 0 8)
国家杰出青年科学基金 (No 4 992 5 61 4 )资助项目
