Seismic facies investigation of the late Cenozoic glacial history of Bransfield Basin, Antarctica

[摘要] Approximately 3000 km of high and intermediate resolution seismic data and 117 sediment cores were examined to reconstruct the late Cenozoic glacial history of Bransfield Basin, Antarctica. The complexity of a glacial setting requires seismic data with vertical resolutions of 20-30 m to adequately image the depositional environments. This study demonstrates the utility of higher resolution seismic records to develop a complete understanding of the complicated nature of glacial environments. Lower resolution data, while appropriate for studying larger-scale features, lack necessary detail and can lead to over-simplified models.Investigation of the seismic facies resulted in characterization and mapping of glacial sub-environments leading to the construction of a subpolar depositional model for glacial-interglacial cycles. In addition, these results help constrain Pleistocene climatic conditions. As seismic facies analysis indicates no significant meltwater activity, it is suggested that temperate deglacial-interglacial conditions did not exist in Bransfield Basin during the time interval studied (Pleistocene? to present). Another outcome of this study was a 13,000-14,000 yr BP minimum age for the end of the last significant glacial period with $>$800 m of ice grounded in $>$600 m of water. Examination of the data and application of the depositional model led to identification of key sites for shallow and deep drilling to further resolve questions of timing and paleoclimate.

[发布机构] Rice University

[效力级别] Geophysics