Assessment of hydrogen isotopic compositions of n-fatty acids as paleoclimate proxies in Lake Biwa sediments

作者：Seki Osamu^*; Kawamura Kimitaka; Ishiwatari Ryoshi

来源：Journal of Quaternary Science, 2012, 27(9): 884-890.

DOI：10.1002/jqs.2577

• Lake Biwa
• n-fatty acid
• hydrogen isotope
• paleoclimate
• sediment

Compound specific hydrogen isotopic compositions (dD) of free and bound forms of n-fatty acids (FA) were measured throughout a 200?m sediment core taken from Lake Biwa to assess application of biomarker dD values to paleoclimate study in this central Japan lake. The results of our study suggest that the sources of the C16 n-FA in the two forms are different, whereas both free and bound C28 n-FA originate from terrestrial plants. The dD of combined (free plus bound) C28 n-FA in the 200?m sediment core shows a large variability, with relatively low and high values during the glacial and interglacial periods, respectively. Based on comparison of our record with other marine and lacustrine paleoclimate data, we found that the sedimentary record of C28 n-FA dD likely reflects the temperature-induced change in dD of summer precipitation. This finding suggests that dD values of C28 n-FA could be used as a proxy for summer paleotemperatures in the sediments of Lake Biwa and other lakes.

• 出版日期2012-12