ZHANG Cheng-jun, ZHANG Wan-yi, ZHANG Li, WANG Xiao-yu, IMBABAZI Berthe

College of Earth Sciences & Key Laboratory of Mineral Resources in Western China(Gansu Province), Lanzhou University, Lanzhou 730000

Abstract：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 δ13Corg were 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.

Key words：western and northeastern China lake surface sediment carbon and oxygen isotopes carbonates

E-Mail: cjzhang@lzu.edu.cn  

Bulletin of Mineralogy, Petrology and Geochemistry Vol.35, No.4, 2016, page 609-617