Holocene lake-level changes of Linggo Co in central Tibet

Lake-level changes are important environmental events. The paleoshorelines of a lake reflect past water levels and record information on paleoclimatic changes. Dating these events places the climatic changes in a time sequence. From shorelines ∼1, ∼4, and ∼6 m above current lake level on the eastern shore of Linggo Co, central Tibet, we collected eight samples for optically stimulated Luminescence dating. Two stratigraphic units, distinguished on the basis of color and sedimentology, were recognized beneath each shoreline. The ages obtained were 0.9 ka (upper layer) and 3.1 ka (lower layer) for lowest shoreline, 1.9 ka (upper layer), and 6.1–9.0 ka (bottom layer) for middle shoreline, and 9.6 ka for high shoreline. Two dates were considered to be unreliable due to incomplete bleaching. We attribute the higher lake levels to increased precipitation brought by the Indian monsoon in the Holocene.

► OSL datings on three shorelines yield ages of 0.9 ka, 1.9 ka and 9.6 ka, respectively.
► Three shorelines are 1 m, 4 m and 6 m higher than present water level, respectively.
► The shorelines correspond to warm wet periods with increased moisture input from the Indian monsoon.