HR: 10:35h
AN: PP32B-02    [Abstracts]
TI: The Initiation of the Southern Central Great Barrier Reef: Multiproxy Study on Periplatform Sediments From ODP Site 1195 on the Marion Plateau (NE Australia)
AU: * Dubois, N
EM: nathalie.dubois@dal.ca
AF: Department of Oceanography, Dalhousie University, 1355 Oxford Street, Halifax, NS B3H 4J1, Canada
AU: Kindler, P
EM: pascal.kindler@terre.unige.ch
AF: Section of Earth Sciences, University of Geneva, Rue des Maraichers 13, Geneva, GE 1205, Switzerland
AU: Spezzaferri, S
EM: silvia.spezzaferri@unifr.ch
AF: Department of Geosciences, University of Fribourg, Ch. du Musee 6, Fribourg, FR 1700, Switzerland
AU: Coric, S
EM: stjepan.coric@geologie.ac.at
AF: Geological Survey of Austria, Neulingstrasse 38, Vienna, 1030, Austria
AB: The sediments deposited at ODP Site 1195 (Marion Plateau, NE Australia) record synchronous shifts in their chemistry, mineralogy, grain size and colour at 6 meters below sea floor. These significant changes are interpreted to reflect the onset of the southern province of the Great Barrier Reef (GBR). An increased deposition of carbonate-rich sediments of neritic origin, coincident with a decline in both sedimentation rate and terrigenous input, is attributed to inshore trapping of materials by the reefs. Based on an age model combining magnetostratigraphic and biostratigraphic data, we propose that the southern province of the GBR initiated between 560 and 670 kyr B.P. Our best estimate concurs with previous studies reporting an age between 500 and 930 kyr B.P., albeit constraining more tightly these earlier age estimates. However, it does not support research placing the birth of the GBR in Marine Isotope Stage 11 (about 400 kyr B.P.), nor the recent theory of a worldwide modern reef development at that time.
DE: 1051 Sedimentary geochemistry
DE: 4863 Sedimentation (1861)
DE: 4916 Corals (4220)
DE: 4944 Micropaleontology (0459, 3030)
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2007 Fall Meeting