HR: 1340h
AN: PP23B-1421    [Abstracts]
TI: Dating New York - Tracking the Retreat of the Laurentide Ice Sheet
AU: * Edwards, A R
EM: are27@columbia.edu
AF: Lamont Doherty Earth Observatory, 61 Geochemistry 61 Route 9W , Palisades, NY 10964
AU: Schaefer, J
AF: Lamont Doherty Earth Observatory, 61 Geochemistry 61 Route 9W , Palisades, NY 10964
AU: Rinterknecht, V
AF: Lamont Doherty Earth Observatory, 61 Geochemistry 61 Route 9W , Palisades, NY 10964
AU: Ivy-Ochs, S
AF: Lamont Doherty Earth Observatory, 61 Geochemistry 61 Route 9W , Palisades, NY 10964
AB: The Laurentide Ice Sheet (LIS) covered the New York City area during the Last Glacial Maximum (LGM) and when it retreated carved out the present topography, exposing fresh bedrock. Although modernization has led to the modification of much of the present landscape, the New York area still features many attributes of the glacial sculpting. These attributes: glacially polished bedrock, erratic boulders and glacial moraines, remain as evidence of past climate change. Long Island represents a terminal moraine of the LIS, while areas in Central Park, Inwood (northern Manhattan) and the Hudson valley display beautiful retreat features. We present surface exposure dates of samples removed from these areas from the measurement of 10Be in them. This allows us to better understand the dynamics of the Laurentide Ice Sheet at the end of the last ice age. We will match the data with existing moraine records from the LIS as well as with mountain glacier records to determine whether or not (i) the LIS and the Scandinavian Ice Sheet were in sync; (ii) the huge LIS reacted more inertial than smaller systems to the climate reorganizations; (iii) the retreat pattern of the LIS.
DE: 9350 North America
DE: 9614 Paleozoic
DE: 5416 Glaciation
DE: 1620 Climate dynamics (3309)
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2004 AGU Fall Meeting