IODP

doi:10.2204/iodp.sp.342.2011

Abstract

The Newfoundland ridges are covered by large-scale sediment drift deposits that accumulated under the Deep Western Boundary Current during the Late Cretaceous and early Paleogene greenhouse. The area is famous because it is the resting place of RMS Titanic, which sank after colliding with an iceberg en route from Southampton, England, to New York City, USA, in April 1912. Integrated Ocean Drilling Program (IODP) Expedition 342 will drill a depth transect between ~2400 and 5000 m water depth into a sequence of rapidly accumulated sediment drifts of Paleogene age on J Anomaly Ridge and Southeast Newfoundland Ridge. Drilling this transect will allow us to study multiple extreme climate events at unprecedented temporal resolution from a high-latitude site during an interval of time when Earth was much warmer than today, featuring a genuinely green Greenland and estimated atmospheric carbon dioxide levels similar to those projected for the end of this century. The targeted sedimentary sequences accumulated directly under the flow path of the Deep Western Boundary Current. These sediments, therefore, will provide an archive of changes in chemistry, flow history, and depth structure of waters exiting the Nordic seas and Arctic Ocean during the transition from an ice-free peak Cenozoic warm interval in the early Eocene to the onset of Arctic sea ice formation and the growth of major ice sheets on Antarctica. Our drill sites are located in a region that climate modeling suggests should have a particularly high-amplitude climate response to orbital forcing, which, together with excellent age control from magnetostratigraphy seen in existing drill cores, should help extend the astronomical timescale through the Cenozoic.

Approximately two days of Expedition 342 ship time will be spent testing the Motion Decoupled Hydraulic Delivery System (MDHDS). The MDHDS is an IODP-funded engineering development and will serve as a foundation for future penetrometer and other downhole tool deployments. The tests will take place at Ocean Drilling Program Site 1073 (Leg 174A), offshore New Jersey, by deploying both the SET-P and T2P pore pressure penetrometers.