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对青藏高原中部纳木错湖泊表层沉积物中总有机碳(TOC)、总氮(TN)、碳氮比(C/N)以及正构烷烃组分和含量等指标进行研究,分析了沉积物有机质的来源及其空间分布特征,进而探讨了影响沉积物有机质空间分布的控制因素以及古湖泊学意义.结果表明,纳木错表层沉积物有机质来源与正构烷烃的组成一致,具有沉水植物>陆生植物>低等菌藻的组成特征.纳木错表层沉积物有机质分布具有典型的空间差异性,其沉积过程主要受湖泊水下地形、河流补给以及湖泊水质等因素影响,表现出从物源向沉积中心富集的特点.纳木错表层沉积物有机质空间分布差异性决定了不同区域的沉积物对环境变化响应具有不同的敏感程度,是利用湖芯沉积进行过去环境变化研究的重要依据.
The contents of total organic carbon (TOC), total nitrogen (TN), carbon / nitrogen ratio (C / N) and n-alkane content in the surface sediments of the Namur Lake in the central Tibetan Plateau were studied. The contents of organic matter Source and their spatial distribution, and then discussed the controlling factors affecting the spatial distribution of the organic matter in the sediments and the significance of paleoclimate. The results show that the source of organic matter in the surface sediment of the Nam Co is consistent with the composition of normal alkanes, with submerged plants> terrestrial plants > The composition of lower bacteria and algae.The distribution of organic matter in the surface sediments of Namur has typical spatial differences.The sedimentation process is mainly affected by the underwater topography of the lake, the supply of rivers and the water quality of the lake, The difference of the spatial distribution of organic matter in the surface sediments of Namur determines that the sediments in different areas have different sensitivity to the environmental changes and is an important basis for the study of the past environmental changes by lake sediments.