The Late Quaternary stromatolite assemblages at Damxung Co have been found on the Qinghai-Tibet Plateau for the first time. The discovery has great significance for elucidation of the paleoenvironmental evolution on the plateau in the Late Quaternary. Geochemical characteristics and 14C ages of these three layers stromatolites are studied in this paper. The result shows that the optimum temperatures for stromatolite growth are 20℃ to 30℃, and that when the temperature is lower than 15℃, the growth of blue algae will stop. At present, the annual mean temperature of lake water is 4.8℃, suggesting that the water temperature then was 10℃ higher than the modern times temperature. The result also shows that 14C ages of these three layer stromatolites are consistent with Bölling, Allevöd and early Holocene warm period events, with mean values of δ¹⁸O and δ¹³C being high in these three layer stromatolites, i.e., -7.23 to -6.6 and 4.75 to 5.65, respectively, suggesting that the air temperature was high. The discovery of three warm stages in this period is of vital value for the establishment of the Late Quaternary climatic-chronological scale of the Qinghai-Tibet.

Qinghai-Tibet Plateau  /  Late Quaternary  /  Damxung Co  /  stromatolite