HR: 0800h
AN: PP21A-1555    [Abstracts]
TI: Global and Regional Climate Correlations During Marine Isotope Stage 7 and Termination III Using a Stalagmite Oxygen Isotopic Record From Dongge Cave, China
AU: * Kelly, M J
EM: kell0738@umn.edu
AF: Department of Geology and Geophysics, University of Minnesota, Minneapolis, MN 55455 United States
AU: Edwards, R L
EM:
AF: Department of Geology and Geophysics, University of Minnesota, Minneapolis, MN 55455 United States
AU: Cheng, H
EM:
AF: Department of Geology and Geophysics, University of Minnesota, Minneapolis, MN 55455 United States
AU: Yuan, D
EM:
AF: Karst Dynamics Laboratory, The Ministry of Land and Resources, Guilin, 541004 China
AU: Wang, Y
EM:
AF: College of Geography Science, Nanjing Normal University, Nanjing, 210097 China
AB: It has previously been suggested that δ¹⁸O variations recorded in stalagmites from Hulu and Dongge Caves in China are related to the intensity of Asian Monsoon precipitation, and that climate in this region is linked to Northern Hemisphere insolation, high northern latitude climate, and other global and regional climate records over much of the last two glacial-interglacial cycles (Wang et al., 2001, Science 294, 2345-2348; Yuan et al., 2004, Science 304, 575-578; Kelly et al., in press). A new stalagmite from Dongge Cave, D10, extends our U-Th dated monsoon record to cover the time period corresponding to the Marine Isotope Stage (MIS) 7 interglacial, including Termination III. The younger portion of the D10 record extends into the penultimate glacial period, enabling a test for replication with previous results from Hulu Cave (Cheng et al., in review). The MIS 7 monsoon δ¹⁸O record exhibits the full glacial-interglacial amplitude, ranging from ~-5 to -9 per mil. U-Th ages have 2σ analytical errors that correspond to <2% of the age. There appear to be several short duration hiatuses in growth, which may complicate the determination of the exact timing and duration of the MIS 7 sub-stages. However, the δ¹⁸O record broadly follows the trend of Northern Hemisphere insolation, with peaks associated with MIS 7a, 7c, and 7e at ~200, 220, and 240 ka BP, respectively. There also appear to be similarities to the δ¹⁸O record from Peqiin Cave, Israel (Bar-Matthews et al., 2003, GCA 67, 3181-3189). By correlating the monsoon record with the Vostok CH₄ record and North Atlantic ice-rafted debris records, we have previously shown that at Terminations I and II, most of the marine oxygen isotope termination, along with the rise in atmospheric CO₂, CH₄, and Antarctic temperature, occurred prior to monsoon strengthening and presumed Greenland temperature rise. The MIS 7/Termination III monsoon record allows further examination of the relationship between the monsoon, insolation, Vostok ice core records, and sea level at major glacial terminations as well as during second order climate transitions.
DE: 1041 Stable isotope geochemistry (0454, 4870)
DE: 1616 Climate variability (1635, 3305, 3309, 4215, 4513)
SC: Paleoceanography and Paleoclimatology [PP]
MN: Fall Meeting 2005