Late Quaternary lacustrine Ostracoda and their implications for hydro-climatic variation in Northeastern Tibetan Plateau

Abstract

Ostracoda from non-marine waters have a significant potential role in monitoring ecological conditions and reconstructing paleoenvironments. During the last decades, the increase in research on ostracods on the Tibetan Plateau (TP) has been achieved, although there are still taxonomical and ecological problems in their application in Quaternary studies. The aim of this review is to summarize the occurrences of ostracods in surface samples from four selected lakes (Qinghai Lake, Lake Donggi Cona, Lake Kuhai and Hala Lake) along the modern monsoon marginal zone on the northeast Tibetan Plateau and to compare the ostracod associations in sediment cores from different sites with available proxy data after re-evaluation of chronologies in order to reconstruct hydroclimatic conditions and monsoon influence during the late Quaternary. Comprehensive reanalysis of ostracod data from selected lakes (including 3 closed and 1 open lake basins) on the northeastern TP shows that their occurrence and disappearance responded sensitively to salinity and related water depth changes during the late Quaternary. This could lead to a re-interpretation of other proxy data related to hydro-climatic interpretation. Ostracod-based reconstructions of lake level changes along the modern summer monsoon marginal zone of the northeastern TP during the late Quaternary indicate an overestimation of the contribution from monsoonal rainfall to strong lake level changes, while the glacier/snow meltwater supply was underestimated in previous studies. This inference sheds more light on moisture source and the interplay between westerlies and Asian Summer Monsoon on the northern TP.