Friday, 31 August 2007
5.PS-122
New insights in the evolution of Antarctic glaciation from depth conversion of well-log calibrated seismic section of Prydz Bay
Valentina Volpi, Michele Rebesco, and Paolo Diviacco. RIMA, Istituto Nazionale di Oceanografia e di Geofisica Sperimentale OGS, Borgo Grotta Gigante 42/c - Sgonico, Trieste, Italy
The understanding of the evolution of the Antarctic Ice Sheet is crucial. An evident change in the geometry of the depositional systems of the Prydz Bay continental margin demarked the initiation of the Prydz Channel Fan which has been inferred corresponding to the transition to a modern polar regime intended as a relatively cold-and dry based ice-sheet with respect to previous polythermal conditions.
We propose geophysical methods (multi-attribute analysis, seismic depth conversion) to correlate the existing litho-and bio-stratigraphic information among three important Ocean Drilling Program drill holes on the Antarctic shelf inPrydz Bay . The revised stratigraphy that we obtained better constrains the Neogene glacial history of the Prydz Bay region, assigning an early late to late early Pliocene age to the transition to a modern polar condition. This age, younger than previously proposed, is consistent with the age inferred for similar geometric changes identified in different Antarctic margins.
We propose geophysical methods (multi-attribute analysis, seismic depth conversion) to correlate the existing litho-and bio-stratigraphic information among three important Ocean Drilling Program drill holes on the Antarctic shelf in