Re-Evaluation and Update of Age Models for Deep Sea Drilling Project Sites 270, 272, and 273 and Implications for Regional Climate and Tectonic History.
Abstract
The ability to understand and model past climatic conditions and tectonic events depends upon our capability to isolate the stratigraphic record of that past time through precise chronostratigraphy Recovery and integration of biostratigraphic, magnetostratigraphic, chemostratigraphic, and radiometric data from geologic sections obtained over the past 30 years from the continental margin of Antarctica and the Southern Ocean, has enabled an ever improving understanding of regional chronostratigraphy. We have incorporated and updated biostratigraphic data for marine diatoms from Deep Sea Drilling Project Sites 270, 272, and 273 in the Ross Sea. New diatom event age data based on recent quantitative work allow refinement of outdated age models for these key cores. Integration into a regional chronostratigraphic framework that incorporates drill cores from the Victoria Land Basin, including the recently recovered ANDRILL 1B and 2A cores, highlights several regional events (unconformities) that likely have global significance. Of particular significance is a regionally extensive break in the stratigraphic records that occurred approximately 14 Ma. This early middle Miocene hiatus likely correlates to climatic cooling at the end of the Miocene Climatic Optimum. The new age models provide key constraint for the network of seismic data in the Ross Sea and will help guide future drilling.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2008
- Bibcode:
- 2008AGUFM.C21B0533L
- Keywords:
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- 1621 Cryospheric change (0776);
- 3030 Micropaleontology (0459;
- 4944);
- 3036 Ocean drilling;
- 4207 Arctic and Antarctic oceanography (9310;
- 9315);
- 9605 Neogene