中文摘要：

河流是有机物从陆地向海输送的重要纽带。研究河流沉积环境中有机物的来源、贡献和分布情况,对于评估陆源有机物的碳循环以及反演环境演变具有重要意义。本文以黄河济南段的柱状沉积物为例,利用碱性CuO把木质素氧化分解为不同的单体并通过GC-FID测定,初步探讨了木质素的垂直分布特征和有机物来源。研究结果表明：木质素的含量Σ8（mg/10gds）的变化范围0.0029-0.60mg/10gds,其Σ8的值整体较低,少数值几乎接近检出限,可能与黄河含沙量大,砂质颗粒物的有机质本身含量较低有关,同时低Σ8很好地揭示了沉积物样品的贫有机质特征;木质素的植被参数S/V和C/V表明其母源植被多以被子植物的叶或草为主,部分区段掺杂着裸子植物草本组织。其降解参数（Ad/Al和P/（V＋S））则揭示了木质素经历了中高程度的氧化降解和较强的去甲基/去甲氧基降解。此外,C/V和3,5-Bd/V（3,5-双羟基苯甲酸/V）的关系说明该研究区域有机物主要来自土壤的贡献。

英文摘要：

River is an important link for the transport of organic matter from land to sea.Studying on the sources,contribution and distribution of organic matter in fluvial sedimentary environment is significant for assessment of terrestrial organic carbon cycle and inversion of environmental evolution.In Ji＇nan section of the Yellow River,the vertical distribution of lignin and the source of organic matter were preliminarily studied by using alkaline CuO oxidation method.The lignin was decomposed into different monomers and the content was determined by GC-FID.The result showed that the lignin content Σ8（mg/10gds）was in the range of 0.0029-0.60mg/10 gds.,which indicated a trend of increase and then decrease with the increase of the depth in general.The values of the Σ8 were relatively low and some values were close to the detection limitation which may be related to large sediment of the Yellow River and the low content of organic matter in sandy particulate.Moreover,it has been proved that the sediment was poor organic matter;The lignin vegetation parameters（S/V and C/V）indicated that the maternal vegetation was dominated by a mixture of nonwoody angiosperm and gymnosperm plants.Its degradation parameters（Ad/Al and P/（V＋S））revealed that the lignin underwent a high degree of oxidation degradation and strong degradation of demethylation/demethoxylation.In addition,the relationship between C/V and 3,5-Bd/V suggested that soil-derived terrestrial organic matter may account to majority composition in most samples.