Collaborative Research: Establishing the Stratigraphy of Glacigenic Bedforms on the Chukchi Borderland, Arctic Ocean, to Reconstruct the History of Pleistocene Arctic Ice Shelves.

0136238

Polyak

This is a collaborative proposal by Principal Investigators at the Ohio State University and Old Dominion University. The Principal Investigators will investigate sediment cores from the Chukchi Borderland that were collected and curated by the U.S. Geological Survey (USGS) in 1992. The core sites are located in an area that contains several generations of glacigenic bedforms, which were mapped by the Science Ice Exercise (SCICEX) survey in 1999. A preliminary lithostratigraphy for these cores has been developed from their physical properties logs and core descriptions. The Principal Investigators will verify and further develop this stratigraphy based on lithological and paleontological (foraminiferal) compositions and paleomagnetic measurements, reinforced by 14C dating and coccolith studies. These approaches will allow them to put the Chukchi Borderland cores into a stratigraphic context for the Amerasian Basin and to correlate them with the Lomonosov Ridge sediment records. The results should help to establish an improved Quaternary age model for the Arctic Ocean. Investigation of glacigenic diamictons recovered by cores on the Chukchi Borderland will aid our understanding of the processes involved in the grounding of ice shelves on submarine rises. By using the composition of glacigenic clasts in sediments as provenance tracers they identify glaciation centers that sustained the ice shelves. This stratigraphically constrained information will yield insights into the Pleistocene glaciation history of both the interior and the periphery of the Arctic Ocean and will improve our

understanding of interactions between continental-based ice sheets and ice shelves.