Lacustrine radiocarbon reservoir ages in Co Ngoin and Zigê Tangco, central Tibetean Plateau

A series of C-14 ages were made in two lake sediment cores from Co Ngoin and Zige Tangco, central Tibetan Plateau, China, using bulk organic carbon, plant remains, chitin of cladocera, and carbonates. The old C-14 ages of the surface sediments in both cores suggests that there is a significant reservoir effect in these lakes. The magnitude of the reservoir age of different material is variable. Authigenic carbonate has the largest reservoir age, while plant remains and chitin show smaller deviations. Due to a lack of terrestrial macrofossils at most depths, a regression approach was used to obtain the approximate C-14 reservoir correction for bulk organic matter, which is 3260 C-14 BP and 2010 C-14 BP for Co Ngoin and Zige Tingco respectively. (C) 2009 Elsevier Ltd and INQUA. All rights reserved