Influencing factors on δ(13C) of organic matter and carbonate in labke sediments on songnen plain

Carbon isotopic compositions of organic matter and carbonate in surface sediments from lakes in Songnen Plain, northeast of China, were carried out.n-alkanes carbon distribution characteristics of the organic matter in lake sediments were also analyzed to identify the source of organic matter and sedimentary environment in these lakes. With the limnological characteristics of water and sediment, the influencing factors on isotopic composition in sedimentary organic matter and carbonate were discussed. The results showed that types of organic matter affected the carbon isotopic composition. 13C of carbonate depleted by input of biologic organic matter and enriched by input of oil pollution. (authors)