20,000-year Environmental Change Reflected by Multidisciplinary Lake Sediments in Chen Co, Southern Tibet
藏南沉错湖泊沉积多指标揭示的2万年以来环境变化

A 20,000-years environmental record is elucidated by analyzing the environmental proxies such as grain size, TOC, TN, C/N, Fe/Mn, Sr/Ba and environmental magnetism parameters from a lake core (TC1) in Southern Tibet area. Results showed that during the period of ca. 19800-18000 Cal aBP, the decreasing temperature was reflected by all analyzed proxies. Temperature appeared a jump rise around ca. 16000 Cal aBP and then had an abrupt decrease. About 15200-12000 Cal aBP, temperature slowly re-rose. However, almost all the proxies indicated that the environment was unsuitable for lives existing during ca. 12000-9500 Cal aBP. Especially during ca. 11600-10400 Cal aBP, the environment became deteriorated. From the beginning of Holocene, the environment experienced 3 obvious warm stages (ca. 9500-7600 Cal aBP, ca. 6800-5800 Cal aBP, ca. 4800-3800 Cal aBP) and 2 cold stages (ca.7600-6800 Cal aBP, ca. 5800-4800 Cal aBP), representing obvious alternation of warm-dry and cold-wet, having the climatic change characteristics of South Asian monsoon (southwest monsoon) zone. Some characters of the 20,000-year climatic and environmental change sequence in Chen Co area had rather good coherence with Greenland ice core records (GISP2) and other environmental records on the Tibetan Plateau, reflecting that the environmental changes in this area had certain global significance.