δ~(13)C values and hydrogen index records in sediment organic matter of RH core of Zoige Basin, eastern Qing-Zang (Tibet) Plateau and their environmental significance

摘要

Total organic carbon (TOC) content correlates very well with hydrogen index (HI) in the sediments of RH core in the Zoige Basin. And the δ~(13)C values of TOC become more positive while both TOC content and HI decline, indicating the subaerial exposure or the lake sediments approaching to the water level. On the basis of the above, RH core sediments are divided into 23 climatic fluctuation stages, including 12 warm-humid stages and 11 dry-cold stages, which can be compared with oceanic oxygen isotope stages, loess profile and polar ice-core records.