固城湖沉积物中羟基酸和α,ω-二元酸的组成分布及其地球化学意义

Occurrence and distribution of hydroxy acids and a, -dicarboxyl acidsin core sediments from Guchenghu Lake, eastern Chinaand their geochemical significance

对固城湖沉积物中呈不同赋存状态的羟基酸和α，ω－二元酸进行了分析，结果表明，在相对含量上，游离类脂组分中的羟基酸和二元酸低于呈结合态和强结合态存在的对应羟基酸和二元酸，指示游离类脂质，尤其是其极性组分在早期成岩作用过程中的稳定性较差。由游离类脂→结合态类脂→强结合态类脂，其中－羟基酸的来源渐趋于单一化，其生源指示意义更加明确。在固城湖沉积剖面１２．２８ｍ之上和之下，沉积物中的强结合态－羟基酸的分布型式及其所指示的细菌群落存在着显著差别，表明沉积环境发生了突变。

The occurrence and distribution of hydroxy acids and a, -dicarboxyl acids in sedimentsfrom Guchenghu Lake, a freshwater lake in eastern China were analyzed with GC and GC/MSD. The concentration of hydroxy fatty acids in the free lipids is much lower than those in thebound and tightly bound lipids, which suggests that the bound and tightly bound lipids are moreresistant to the early diagenesis process. The distribution patterns of tightly bound -hydroxyfatty acids along the sedimentary profile of Guchenghu Lake reveal that the bacteria populationin the sedimentary environment had changed significantly at the average depth of 12.28 m.