【摘要】 该文以江汉平原不同埋藏深度的湖积、冲-湖积、残坡积3种沉积相黏土沉积物中的有机碳形态的分布特征为研究对象,通过测试钻孔沉积物粒径及TOC、HFOC、LFOC,分析不同沉积环境条件下有机碳的赋存特性及粒径组分对有机碳形态和含量的影响。结果表明:(1)湖积相钻孔A粒径频率曲线主要为单峰,沉积环境较稳定,TOC含量为1.72～17.71 mg/g,呈波动式逐渐降低;(2)冲积相钻孔B粒径频率曲线有单峰、双峰、三峰3种峰型,水动力条件不稳定,TOC含量为1.77～19.57 mg/g,不同深度含量差别较大;(3)坡积相钻孔C粒径频率曲线主要为双峰,TOC含量为1.44～4.37 mg/g,含量较低且具有波动性,受成土母质碳含量影响较大;(4)TOC和HFOC普遍与颗粒较细的粒径组分呈正相关,黏粒和细粉粒对沉积物有机碳存在较强的吸附作用,对有机碳的保存有重要的影响。更多还原

【Abstract】 The distribution characteristics of organic carbon in clay sediments of three sedimentary facies in different burial depths in Jianghan Plain, including lacustrine, alluvial-lacustrine and el-dlQ were studied. The occurrence characteristics of organic carbon and the effects of particle size components on the morphology and content of organic carbon were analyzed by measuring the grain size and TOC, HFOC, LFOC of borehole sediments under different sedimentary environments. The results show that the grain size frequency curves of borehole A in lacustrine facies are mainly unimodal. The sedimentary environment is stable, and the TOC content is 1.72～17.71 mg/g, which is gradually decreasing in a fluctuating manner. The grain size frequency curves of borehole B in alluvial facies have many peaks, such as unimodal, bimodal and three peaks, and the hydrodynamic conditions is unstable, and the TOC content is 1.77～19.57 mg/g. The frequency curves of borehole C particle size of boreholes in slope sedimentary facies are mainly bimodal, and the TOC content is 1.44～4.37 mg/g. The content of TOC is low and fluctuant, which is greatly influenced by the carbon content of soil parent material. TOC and HFOC are generally positively correlated with the finer particle size components. Cosmid and fine powder fraction have strong adsorption on organic carbon in sediments, which has an important impact on the preservation of organic carbon.更多还原