Reviewed stratigraphy of the southern Scotia Sea basins (Antarctica): preliminary results on core-log-seismic integration from IODP Expedition 382
Abstract
The large-scale reconstruction of the opening of the Drake Passage and the formation of the Scotia Sea has been attempted in previous works mainly based on integration of different geophysical datasets. However, the lack of consensus on timing and development models has prevented an accurate reconstruction of the major regional events and their global implications. In the southern part of the Scotia Sea, continental banks generated during the breakup of the former continental bridge between South-America and the Antarctic Peninsula bound small isolated sedimentary basins. These basins developed under distinctive phases of oceanic spreading in the regional back-arc extensional context. The sedimentary record of the southern Scotia Sea basins contains the evolutionary history of the regional tectonic, oceanographic and climatic events during the Cenozoic. Three of the five sites drilled during the recent IODP Expedition 382 recovered a nearly continuous record of the upper part of the sedimentary cover of two of these basins, Dove and Pirie. Thus, IODP Expedition 382 provided the first accurate age model of the upper sedimentary record of Dove and Pirie basins back to the late Miocene. This work correlates IODP Expedition 382 physical properties data and age models with previous morpho-structural and seismo-stratigraphic analyses. The estimated ages of the major changes in the sedimentary pattern have been revised based on the site data, whereas the core-log-seismic tie allows us to correlate local events to a regional context. These preliminary results demonstrate the interplay among tectonics, oceanography and climate in the construction of the Scotia Sea sedimentary stacking pattern from late Miocene. Major insights are linked to the oceanographic gateway development, its influence on the Antarctic Circumpolar Current pattern and the outflow of Antarctic Bottom Water to northern latitudes, as well as the isolation of the Antarctic continent linked to the oscillation of the Antarctic Ice Sheet.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMPP52A..02P
- Keywords:
-
- 0726 Ice sheets;
- CRYOSPHERE;
- 0732 Icebergs;
- CRYOSPHERE;
- 4901 Abrupt/rapid climate change;
- PALEOCEANOGRAPHY;
- 4910 Astronomical forcing;
- PALEOCEANOGRAPHY