Abstract ATM-9305750 Brenner, Mark Title: Paleoclimate of Southwest China: Development of the Asian Monsoon This award suports a study of sediment cores from four Yunnan lakes which will be used to reconstruct the paleoclimate of southwest China from late Pleistocene to present . Long, 14C-dated sections (>10kyr BP) have been obtained. Contrary to "predictions" from general circulation models, pollen, diatom and geochemical data indicate a shift from wet late Pleistocene to drier early Holocene conditions. The sediment record also suggests lake-level shifts during the Holocene. Chronologic resolution of paleoclimatic records will be enhanced by close-interval sampling and AMS dating. Stable isotope and trace metal ratios in sedimented ostracod shells will be used to test previous paleoclimatic inferences and establish whether late-Pleistocene, high lake levels were a consequences of glacial meltwater input. Paleoenvironmental reconstruction will also be based on stable isotope signals in carbonates and organic matter. Proxy paleoclimatic data from southwest China will shed light on the development of the Asian monsoon system and can be used to test moisture simulations from general circulation models.
