HR: 11:35h
AN: PP32A-06 INVITED    [Abstracts]
TI: Structure of the Last Glacial-Interglacial Transition in New Zealand's Southern Alps
AU: * Kaplan, M R
EM: mkaplan@ldeo.columbia.edu
AF: LDEO of Columbia Univ., 61 Route 9W, Palisades, NY 10964,
AU: Schaefer, J M
EM: schaefer@ldeo.columbia.edu
AF: LDEO of Columbia Univ., 61 Route 9W, Palisades, NY 10964,
AU: Putnam, A E
EM: Aaron_Putnam@umit.maine.edu
AF: Climate Change Institute, Univ. of Maine, Bryand Global Sciences Center, Orono, ME 04469,
AU: Denton, G H
EM: gdenton@maine.edu
AF: Climate Change Institute, Univ. of Maine, Bryand Global Sciences Center, Orono, ME 04469,
AU: Finkel, R
EM: finkel1@llnl.gov
AF: Lawrence Livermore National Laboratory, 7000 East Ave, Livermore, CA 94550,
AU: Doughty, A
EM: Alice_Doughty@umit.maine.edu
AF: Climate Change Institute, Univ. of Maine, Bryand Global Sciences Center, Orono, ME 04469,
AU: Barrell, D J
EM: D.Barrell@gns.cri.nz
AF: GNS Science, Private Bag 1930, Dunedin, 9054, New Zealand
AU: Andersen, B G
EM: gdenton@maine.edu
AF: University of Oslo, PO Box 1047, Oslo, 0316, Norway
AU: Schwartz, R
EM: roseanne@ldeo.columbia.edu
AF: LDEO of Columbia Univ., 61 Route 9W, Palisades, NY 10964,
AB: There is a debate concerning the timing and magnitude of paleoclimate change during the last glacial to interglacial transition in the middle to high latitudes of the Southern Hemisphere. To address the controversy, we obtained an extensive ¹⁰Be chronology consisting of 41 boulder ages from well-preserved moraines in the central part of the South Island of New Zealand, including the Ben Ohau Range, ~44°S. This moraine chronology documents glacier/advance retreat events reflecting paleoclimate changes in the southern mid- latitudes. The most extensive glacial events during this period occurred between 14-13 and at ~12 ka, which were followed by recessional moraine building events at ~11 and ~10 ka. We conclude that 1) the paleoclimate of New Zealand from ~15 to 10 ka was multifaceted and it did not include a scenario whereby only one major glacial event occurred, for example, coeval with the Antarctic Cold Reversal (ACR) or Younger Dryas (YD) chron 2) despite net overall recession, ice repeatedly deposited moraines until the beginning of the Holocene. We speculate that the New Zealand moraine record contains a signature of both regional and global climate dynamics at the end of the last ice age.
DE: 1105 Quaternary geochronology
DE: 1150 Cosmogenic-nuclide exposure dating (4918)
DE: 1625 Geomorphology and weathering (0790, 1824, 1825, 1826, 1886)
DE: 1824 Geomorphology: general (1625)
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2007 Fall Meeting