Late Pleistocene Sediment Provenance and Paleoenvironmental Changes in the East Siberian Shelf Margin: Insights From Mineralogical and Nd Isotope Analysis

Abstract

This study examines sediment core ARA10C-St16 from the East Siberian Shelf margin, which preserves a high-resolution sedimentary record since Marine Isotope Stage 4 (MIS 4), and divides the core into five stratigraphic units. Mineralogical and geochemical proxies reveal that Unit 5, corresponding to the glacial period of MIS 4, shows characteristics typical of sediments from the East Siberian Sea, indicating sediment supply from nearby rivers or continental erosion. Units 2 and 3 both record increased input of sediments from North America, reflecting distinct phases of Laurentide Ice Sheet (LIS) dynamics. Unit 3, corresponding to a stadial phase within MIS 3, is interpreted to reflect sedimentation associated with LIS expansion and iceberg calving from the Canadian Arctic Archipelago. In contrast, Unit 2 is attributed to the Last Deglaciation during MIS 2 and reflects sediment delivery during LIS retreat, likely dominated by fine-grained material transported from the Beaufort Sea region. The absence of typical glacial muds from MIS 2 in the study core suggests that the ESIS may have completely covered the area, limiting sediment accumulation. In interglacial/interstadial periods, Units 1 and 4 predominantly reflect Eurasian sources, with increased smectite content suggesting input from the Laptev Sea, particularly during periods of low sea level. These findings constrain late Quaternary sediment dispersal and glacial-marine interactions in the western Arctic, informing future reconstructions of ice-sheet dynamics and sediment transport under changing climates.