Radiocarbon concentration of lake sediment cellulose from Lake Erhai in southwest China

To improve age models for lake sediment cores without suitable C-14 dating materials such as terrestrial plant fossils, we investigated the radiocarbon dating of lake sediment cellulose. The cellulose fraction in the sediments was obtained by a sequential decomposition of other organic matter, and subsequently dated by AMS. In general, C-14 ages of the lake sediment cellulose obtained from a 10-m sediment core from Lake Erhai on the Yunnan-Guizhou Plateau are in agreement with C-14 dates from terrestrial plant fossils. For the early Holocene, however, differences of up to 1000 C-14 years are observed between lake sediment cellulose and terrestrial plant fossils. This disagreement is probably caused by the contribution of C-14-depleted cellulose synthesized by aquatic plants/algae in the lake. To obtain a precise and accurate chronology based on C-14 ages of lake sediment cellulose, the origin of lake sediment cellulose needs to be established. (c) 2007 Elsevier B.V. All rights reserved.