淡水湖泊环境沉积单体脂类生物标志化合物氢同位素组成特征及其成因机制研究

Hydrogen isotopes of lipid biomarker compounds in sediments have a widely applied prospect. However, their genesis is a scientific question needed to be resolved. This research project will analyze hydrogen isotopes of individual saturated hydrocarbons, fatty acids and alcohols in various kinds of organisms from freshwater lake and its surrounding area as well as from modern sediments from the freshwater lake by means of GC-TC-IRMS. The hydrogen isotopic compositions of lipid biomarkers in organisms from freshwater lake and its surrounding area as well as modern sediments from the freshwater lake will be determined. On the base of the study on the change of hydrogen isotopic compositions of lipid biomarker compounds from organisms to modern sediments and genetic relationships between the hydrogen isotopic compositions of lipid compounds from organisms and modern sediments and hydrogen isotopic compositions of water source as well as environmental factors (temperature, humidity, height and latitude), the functions of organic matter source, sedimentary environment, biosynthetic process, biogeochemistry, and earlier sedimentation on the compositions of hydrogen isotopes of lipid biomarker compounds in organisms and sediments will be demonstrated. Characteristics of hydrogen isotopic compositions of lipid biomarker compounds in sediments in freshwater lake and their genetic mechanisms will be elucidated. This study will provide the scientific data and theoretic evidences for the wide appliance in the field of organic geochemistry.

生物标志化合物氢同位素具有广阔的应用前景，但是其成因特征是目前迫切需要解决的科学问题。本课题通过现代淡水湖泊典型环境中水生生物及其周围陆生植物、现代沉积物样品的脂类化合物单体氢同位素分析，确定淡水湖泊沉积环境中各类生物体和现代沉积物的脂类生物标志化合物单体氢同位素组成特征。通过研究淡水湖泊典型沉积环境中有机质从生物体到早期沉积阶段中脂类生物标志化合物单体氢同位素变化，总结这些生物、沉积物中脂类化合物单体氢同位素组成与水源氢同位素组成和环境因子（如温度、湿度、高度、纬度等）之间的成因关系，确定母质来源、沉积环境、生物合成过程、生物地球化学作用和早期沉积作用对脂类生物标志化合物单体氢同位素组成影响，阐明淡水湖泊相沉积脂类生物标志化合物氢同位素组成特征及其成因机制，为应用研究（如油气地化和环境地化等）提供淡水湖泊中有机质早期沉积阶段的单体脂类生物学标志化合物氢同位素新的基础数据和理论依据。

沉积生物标志化合物氢同位素具有广阔的应用前景，但是其成因特征是目前迫切需要解决的科学问题。本课题对云南抚仙湖和甘南尕海湖现代淡水湖泊地区各类生物样品和沉积物样品中正构烷烃生物标志化合物单体氢同位素进行了分析，研究了低纬度亚热带与中纬度寒冷气候带地区淡水湖泊沉积环境中生物和沉积物的正构烷烃生物标志化合物单体氢同位素组成特征，确定了水源氢同位素组成、环境因子、母质来源、沉积环境、生物合成过程和早期沉积作用的生物地球化学作用对生物标志化合物单体氢同位素组成的影响，建立了高原地区湿润气候-淡水湖和干燥气候-咸水湖生态环境系统中植物及沉积物的不同碳数正构烷烃δD值分布样式，以及低纬度亚热带木本-草本植物和中纬度寒冷气候带草本植物生态环境系统中沉积正构烷烃δD值分布样式，阐明了淡水湖泊相沉积生物标志化合物氢同位素组成特征及其成因机制，为淡水湖泊中沉积单体生物标志化合物氢同位素的应用研究提供了科学数据和依据。