NEOGENE SEISMIC STRATIGRAPHY AND SEDIMENT VOLUMES, VICTORIA LAND BASIN, MCMURDO SOUND, ANTARCTICA

Antarctic tectonic and environmental changes during the Paleogene and Neogene are recorded in sedimentary strata of the Victoria Land Basin and Terror Rift in the southwestern Ross Sea. Neogene strata are sparsely sampled by drillcore, however the existing cores are tied to regional stratigraphic architecture by seismic reflection data. This study is focused on seismic reflection interpretation and sediment volume calculations, targeting reflectors with age constraints from drillcore data. Regional seismic stratigraphic boundaries identified by previous authors, as well as new seismic packages, are being mapped in detail over the McMurdo Sound region with increased lateral extent. Depositional patterns tracked within seismic reflection profiles are used to assess the roles of ice sheet advance/retreat and tectonic processes in deposition of the rift basin fill.

The generalized view of cold-based ice sheets in arid, polar deserts is that they minimally erode the landscape. Interpretation of ancient landscapes in the Transantarctic Mountains that border the study area has led previous workers to suggest that little sediment was produced and deposited since ~14 Ma in this region of Antarctica. This proposal will be tested in this study using sediment volume calculations. Sediment volume results, in combination with an ice sheet model, can be used in a backstacking procedure to assess landscape modification as a result of cold-based ice sheet cover. Results help to decipher tectonic and climatic influences on sedimentation within Victoria Land Basin in McMurdo Sound, Antarctica, and lead to a better understanding of cold-based ice sheet evolution.