Palaeoclimatic changes in the Qinghai Lake area during the last 18,000 years

摘要

Multi-proxy analysis of a sediment core from Qinghai Lake, including pollen, carbonate, TOC, TN and δ~(13)C of organic matter, was used to document regional climatic changes during the last 18,000 years. Climate was very cold and dry before 16.9 cal. kyr BP. The warm and wet period, which began at about 14.1 cal. kyr BP, culminated at 6.5 cal. kyr BP and came to its end at about 4.5 cal. kyr BP. After that, the climate gradually became colder and drier. During the transitional period from the Late Glacial to the Holocene the climate fluctuated frequently. The short-term climatic oscillations, including the Bolling, Alleroed, Younger Dryas and the cooling event at ca. 8.2 cal. kyr BP, appear to be recorded in the Qinghai Lake sedimentary record. The climatic evolution in the Qinghai Lake area during the past 18,000 years indicates that solar insolation changes on the ten-thousand-year scale are the likely driving force of the East-Asia monsoon.