Late quaternary ice-rafted detritus events in the Chukchi Basin, western Arctic Ocean

Abstract

The late Quaternary ice rafted detritus (IRD) events in the Chukchi Basin, western Arctic Ocean are indications of the provenance of the coarser detritus and ice export events, and also document the evolutionary histories of Beaufort Gyre and the North American Ice Sheet (NAIS). The sediment of core M03 from the Chukchi Basin was selected to study the regional response to the ice export events and the NAIS variability. The stratigraphic framework of M03 was established by a combination of lithological features and downcore color change cycles, AMS14C dating with foraminifera abundance and IRD events. The core was also compared with the adjacent core NWR 5 from the Northwind Ridge area. The core extends back to Marine Isotope Stage (MIS) 7. A sedimentary hiatus of 10–20 ka might occur between 16 to 20 cm core depth. Seven IRD events are distinguished from the studied core and are presented during the early MIS 1, MIS 3, MIS 5 and late MIS 7. These IRD are transported by sea ice and icebergs, which were exported to the Beaufort Sea from the M’Clure Strait Ice Stream, Canadian Arctic Archipelago, and brought to the Chukchi Basin by the Beaufort Gyre.