delta D values of individual n-alkanes in sediments from the Chaka salt lake (China) and terrestrial plants from the surrounding area

作者：Duan, Yi^*; Zhao, Yang; Sun, Tao; Zhang, Xiaoli

来源：Geochemical Journal, 2014, 48(3): 321-329.

DOI：10.2343/geochemj.2.0308

• Chaka salt lake
• sediment
• plant
• n-alkane
• hydrogen isotope
• biological source

Molecular distribution and compound-specific hydrogen isotopic ratios (delta D) of n-alkanes in shallow-water surface sediments from the Chaka salt lake and from various terrestrial plants in the surrounding area were measured to obtain a better understanding of the relationship between sedimentary n-alkanes in salt lakes and their biological sources. The nalkanes in the terrestrial plants exhibited a modal distribution, maximizing at n-C-25 or n-C-27 with average chain length (ACL) values ranging from 26.6 to 27.7. The ACL values of the sediments were similar to those of terrestrial herbaceous plants from the study area. The average n-alkane delta D value (-81.7%0) for the woody-plant leaves was higher than that for terrestrial herbaceous plants (-164.3%0). The average delta D values of n-alkanes in the sediments ranged from -163.8%0 to -127.7%0, which fall between the delta D values in herbaceous and woody plants, but closer to those in terrestrial herbaceous plants from the study area. This similarity of the n-alkane distributions, and delta D values of sediments and plants suggests that n-alkanes in the sediments are likely to be derived mainly from terrestrial herbaceous and partly from woody plants.

• 出版日期2014
• 单位中国科学院地质与地球物理研究所; 中国科学院地质与地球物理研究所兰州油气资源研究中心