A sedimentary record from the Makarov Basin, Arctic Ocean, reveals changing middle to Late Pleistocene glaciation patterns

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

“…Previous research reported that Ob and Yenisei rivers dammed in the eastern Ural Mountains indicate development of EAIS during mid-Weichselian (Jakobsson et al, 2016;Larsen et al, 2006;Mangerud et al, 2001Mangerud et al, , 2004. It is known that the Siberian Large Igneous Province, at the point where the Yenisei River flows through, is an important source of smectite, which could be related to EAIS activities (Dong et al, 2020;Xiao et al, 2021). However, compared to the results of , the faint smectite signal observed in this study shows that few EAIS sediments were transported to the E25 core area.…”

“…Since no similar signal has been recorded in the cores from the eastern Arctic Ocean, it is thought that the BG may not have strongly affected the study region and in fact, may have possibly shrunk inward toward the center of the Canada Basin during the stadial MIS5b and 5d, despite the BG being dominant during MIS5 throughout the interglacial period (Adler et al, 2009;Bischof & Darby, 1997;Phillips & Grantz, 2001). A relatively distinct IRD event and smectite input accompanied by lightening Nps-δ 18 O during MIS5b in the LR core PS2185, similar to the early sediments of MIS6, has been interpreted to represent the EAIS drainage during the early Weichselian (Spielhagen et al, 2004;O'Regan et al, 2010), which corroborated different ice sheet configurations that were reconstructed for MIS5b and 5d (Batchelor et al, 2019;Xiao et al, 2021).…”

“…However, have also attributed this period to be dominated by sediments from the East Siberian Shelf, representing the input of glacial East Siberia, which was confirmed by the inference of geophysical records (Joe et al, 2020;Schreck et al, 2018). However, additional cores from the Makarov and Canada basins lack evidence of eastern Siberian sources during this period, indicating that impact of SIS, if any, was limited (Xiao et al, 2021). No evidence of glacial (dammed) lakes in eastern Siberia has yet been identified (Brigham-Grette, 2001;Svendsen et al, 1999); therefore, more evidence is needed to assess the expansion of SIS during the MIS4 period.…”

“…In this study, a similar event was observed in other PWLs (∼MIS5d, 5a, and 3), which also contained Nps-δ 18 O excursions with decreased illite and chlorite (Figures 2 and 5). This assemblage resembles the composition of what is known as the Beaufort Sea sediments, originating primarily from the Mackenzie River and northern Alaska (Naidu et al, 1971;Xiao et al, 2021), while the relatively short-term freshwater events occurring in those intervals could be attributed to LIS eruptions and collapses (Jang et al, 2013;Klotsko et al, 2019;Poore et al, 1999;Spielhagen et al, 2004).…”

“…According to this and other studies, Nps-δ 18 O light excursions occurred in MIS5e and early MIS5c in both E25 and surrounding cores, accompanied by not only increased kaolinite but also increased illite and plagioclase (Figure 5). This can be explained in that the co-occurrence of Eurasian materials with the materials from LIS probably resulted from shifts in the Trasnpolar Drift and BG circulation systems (Wang et al, 2018;Xiao et al, 2021). This indicates that non-glaciated eastern Siberia was a significant provenance for sediment in the ESCM during MIS5 (Wang et al, 2021), similar to the situation in MIS7 and other interglacial/interstadial periods.…”