Carbon isotopes are measured for individual long-chain n-alkanes in sediments from the Nansha Sea. The features of carbon isotopic compositions of individual n-alkanes and their origins are studied. The results show t...Carbon isotopes are measured for individual long-chain n-alkanes in sediments from the Nansha Sea. The features of carbon isotopic compositions of individual n-alkanes and their origins are studied. The results show that the long-chain n-alkanes have a light carbon isotopic composition and a genetic feature of mixing sources, and low-latitude higher plants and microbes are considered to be their main end member sources. Based on the abundances and carbon isotopic compositions of individual n-alkanes, the fractional contributions of the two end member sources to individual n-alkanes are quantitatively calculated by using a mixing model. The obtained data indicate that the fractional contributions of the two biological sources are different in the three samples. A trend is that the contribution of microbes increases with the depth. These results provide the theory basis and quantitatively studied method for carbon isotopic applied research of individual n-alkanes.展开更多
基金This work was supported by the National Natural Science Foundation of China (Grant No. 40072040)the Important Direction Project of Knowledge Innovation in Resource and Environment Field, the Chinese Academy of Sciences (Grant No. KZCX2-111) the Found
文摘Carbon isotopes are measured for individual long-chain n-alkanes in sediments from the Nansha Sea. The features of carbon isotopic compositions of individual n-alkanes and their origins are studied. The results show that the long-chain n-alkanes have a light carbon isotopic composition and a genetic feature of mixing sources, and low-latitude higher plants and microbes are considered to be their main end member sources. Based on the abundances and carbon isotopic compositions of individual n-alkanes, the fractional contributions of the two end member sources to individual n-alkanes are quantitatively calculated by using a mixing model. The obtained data indicate that the fractional contributions of the two biological sources are different in the three samples. A trend is that the contribution of microbes increases with the depth. These results provide the theory basis and quantitatively studied method for carbon isotopic applied research of individual n-alkanes.