HR: 0800h
AN: PP11A-0215    [Abstracts]
TI: Precipitation Fluctuation In The Past 5000 Years In The Northern Vietnam Inferred From Stalagmite Geochemical Data
AU: * Lin, Y
EM: f94224117@ntu.edu.tw
AF: Department of Geosciences, National Taiwan University, No.1, Sec.1, Roosevelt Rd., Taipei, 106, Taiwan
AU: Chen, Y
EM: ygchen@ntu.edu.tw
AF: Department of Geosciences, National Taiwan University, No.1, Sec.1, Roosevelt Rd., Taipei, 106, Taiwan
AU: Shen, C
EM: river@ntu.edu.tw
AF: Department of Geosciences, National Taiwan University, No.1, Sec.1, Roosevelt Rd., Taipei, 106, Taiwan
AU: Lam, D D
EM: ddinhlam@yahoo.com
AF: Institute of Geological Science, Vietnamese Academy of Science and Technology, Hoang Quoc Viet Str., Nghia Do, Cau Giay, Hanoi, 084, Viet Nam
AB: We present geochemical proxy records of 2 stalagmites, S14-4 and S14-B collected respectively from the inner and outer chambers of the cave S14, located at Son La province, northern Vietnam, over the past 5000 years. The stalagmite S14-4 provides a serial δ¹⁸O record from 5000-350 yrs B.P. High growth rate and depleted δ¹⁸O values suggest a relatively wet condition at the beginning of mid Holocene. After a transition period at 4000-3000 yrs B.P., a dry interval in the late Holocene is revealed. Three obvious hiatuses recorded in the stalagmite S14-B were dated as 4800-4200, 3200-2750, and 2150-1750 yrs B.P. These discontinuities coincide with the periods of low δ¹⁸O values of S14-4, which implies that there were 3 centennial-scale dry events. High uranium concentration of 2-12 ppm at the windows of 4200-3200 yrs B.P. of S14-4 and 4200-2150 yrs B.P. of S14-B indicates a strongly chemical weathered outcome. Events of the Medieval Warm Period and Little Ice Age can also be recognized in δ¹⁸O records.
DE: 1600 GLOBAL CHANGE
DE: 1605 Abrupt/rapid climate change (4901, 8408)
DE: 1637 Regional climate change
DE: 1650 Solar variability (7537)
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2007 Fall Meeting