 1Department of Geology, Hamilton College, Clinton, New York 133232NSF Accelerator Laboratory, University of Arizona, Tucson, Arizona 857213Marine Geology Department, Geological Survey of Japan, 1-1-3 Higashi, Tsukuba, Ibaraki 305 JapanAntarctic ice sheet geochronology isotopes glacial geology paleoclimatology middle Holocene sediments C-14 Antarctica East Antarctica absolute age marine sediments carbon Cenozoic radioactive isotopes Holocene Quaternary 