中文摘要：

湖泊沉积物中碳酸盐碳、氧和有机质碳同位素组成受湖泊环境介质的控制,可以有效地指示环境演化过程。通过对中国东北和西部青藏高原、新疆现代湖泊表层沉积物的碳酸盐的碳、氧同位素组成（δ13C、δ18O）、有机碳同位素组成（δ13Corg）,以及有机质含量（TOC）、C/N分析研究,发现当湖泊中以浮游植物来源有机母质为主时,其δ13Corg为-30‰~-23‰;以硅藻为主的藻类来源时,δ13Corg为-30‰~-16‰;以挺水植物来源,δ13Corg为-30‰~-24‰;沉水植物来源,δ13Corg为-24‰~-16‰;以水生植物和陆生植物来源为主时,δ13Corg为-30‰~-20‰;当以陆生植物来源为主时,其δ13Corg为-26‰~-24‰。当西北地区半封闭湖泊表层沉积物中碳酸盐含量大于30%时,湖泊表现出δ13C、δ18O之间较好的正相关性,TOC主要以内源有机质来源为主。

英文摘要：

Carbon and oxygen isotopic compositions of carbonates and carbon isotopic compositions of organic matters of the bulk lake sediment are controlled by chemical parameters of lake water and ecological conditions of the catchment,so,they can indicate the evolution process of lake.Carbon and oxygen isotopic compositions（δ13C and δ18O） of carbonates and carbon isotopic compositions（δ13Corg） of organic matters in bulk sediments,and total organic matter contents（TOCs）,C / N ratios were analyzed for lakes in western and northeastern China in this paper.The results indicated that δ13Corgwere in the ranges of-30‰--23‰,-30‰--16‰,-30‰--24‰,-24‰--16‰,-30‰--20‰ and-26‰--24‰ when the major sources of organic matters of lake sediments were phytoplankton,diatom,merged aquatic plants,submerged aquatic plants,aquatic-terrestrial plants and terrestrial plants,respectively,and that a highly positive covariance of δ13C and δ18O was found when carbonate contents in the bulk sediments were much more than 30%,and that TOCs were mainly contributed by endogenesis aquatic plants.