Sedimentary Record of Glacial Impacts and Melt Water Discharge off the East Siberian Continental Margin, Arctic Ocean

Abstract

AbstractThe East Siberian Continental Margin is a major constituent of the western Arctic Ocean, ideal for studying the evolutionary history of the Siberian Ice Sheet (SIS) based on its unique geographical location and medium‐depth bathymetry. For this study, the sedimentary core CHINARE‐ARC07‐E25 (E25) was analyzed, revealing nearly continuous stable oxygen isotope and mineralogy records that preserved scenarios of the SIS development. Lithostratigraphic evidence suggests that the stratigraphic range of E25 extends to marine isotope stage (MIS) 7. Stable oxygen isotope analysis reveals multiple strong, light‐oxygen isotopic excursions since the penultimate glacial, accompanied by multiple patterns of ice rafted debris content and mineralogy. Based on these isotopic events, the potential factors causing the excursions and the provenance of drainage were evaluated. It was found that the excursion events recorded in pink‐white carbonate detritus layers could be related to the retreat of the Laurentide Ice Sheet. The most typical events, occurring during the deglaciation periods of MIS6/5e and MIS4/3 to early MIS3, were characterized by involving a mixture of two or more sources, and could be used to trace the activity of the SIS, which has been ignored in previous studies. Findings of this study are expected to advance the understanding of SIS contribution to the western Arctic Ocean basin development, which is important for interpreting global climate change behavior of similar ice sheets in the Arctic region.