EAST ASIAN MONSOON CLIMATE DURING THE LATE PENULTIMATE GLACIATION BASED ON STALAGMITE RECORDS

Two stalagmites are from Hulu cave, which is 1 600 m above sea level (ASL) in Nanjing. 11 sub-samples are dated by Finnigan MAT 262-RPQ at the Isotope Laboratory of Geology and Geophysics Department, Minnesota University, USA, and all ²³⁰Th ages are in stratigraphic order. The results provided a high-resolution paleoclimate record for East Asian monsoon area during a time interval from 155 to 128 kaBP of the penultimate glaciation.
In order to check reliability of the stalagmite δ¹⁸O record, we compared δ¹⁸O records of these two stalagmites, for both grew contemporaneously during a time interval from 154.5 to 133 kaBP. The general replication of δ¹⁸O values of contemporaneous growth for 21.5 ka suggests fidelity of δ¹⁸O values as a proxy of paleoclimates.
There were eight remarkable apexes in our stalagmite δ¹⁸O record, which show a mean shift of 1.5‰ in δ¹⁸O, lasting about 2ka, and a mean frequency of 2 ka. It bears a striking resemblance to D/O events during last glacial period in terms of structure and transition well expressed in the Hulu δ¹⁸O records. It is therefore likely that the dramatic climate fluctuation during the last glaciation may have occurred pervasively in the early glaciation time in Asian monsoon climates. Climate instability of glacial period may be also related to changes in the ice-sheets and tropical oceanic/atmospheric circulation.