North American origin of “pink–white” layers at the Mendeleev Ridge (Arctic Ocean): New insights from lead and neodymium isotope composition of detrital sediment component

Sedimentary record from the Canada Basin, Arctic Ocean: implications for late to middle Pleistocene glacial history

“…Especially high LIS scores characterize PW layers 2 and 3 attributed to MIS 5d and late MIS 3, respectively. A similar, LIS-dominated pattern likely represents the last deglaciation as indicated by a number of provenance studies (e.g., Stokes et al, 2005;Jang et al, 2013;Bazhenova et al, 2017).…”

“…As has been suggested in earlier studies (e.g., Stokes et al, 2005;Polyak et al, 2009), we infer that the dolomite peaks are related to pulses of massive iceberg discharge from the LIS during the periods of its destabilization and disintegration. Furthermore, radiogenic isotope studies demonstrate that fine sediment in the dolomitic peaks also has North American provenance (Fagel et al, 2014;Bazhenova et al, 2017). These results indicate that dolomite may have been transported not only by icebergs but also in meltwater plumes coming during deglaciations from the Canadian Archipelago or the Mackenzie River.…”

“…These sediments likely represent deposition from suspension plumes, potentially marking especially strong deglacial meltwater discharge. A prominent fine-grained, finely laminated interval within MIS 4 deglaciation (possibly extending into MIS 3) has been reported from multiple cores across the Chukchi Basin-Mendeleev Ridge area Matthiessen et al, 2010;Wang et al, 2013;Bazhenova et al, 2017).…”

“…0.5-0.6 Ma. In this work we capitalize on earlier studies on the distribution of bulk and/or clay minerals in surface and downcore Arctic Ocean sediments (e.g., Vogt, 1997;Stein, 2008;Krylov et al, 2014;Zou, 2016), corroborated by more targeted provenance proxies, such as radiogenic isotopes (Fagel et al, 2014;Bazhenova et al, 2017), heavy minerals (Stein, 2008;Kaparulina et al, 2016), composition of coarse debris (Bischof et al, 1996;Wang et al, 2013), and iron oxide grains (e.g., Bischof and Darby, 1997;Darby et al, 2002). To optimize the PCA results for clarifying relationships between various sedimentary proxies, we plotted the leading PC loading scores as biplots in the PC 1-2 and PC 3-4 space (Fig.…”

“…We infer that sediment with a concerted enrichment in smectite, kaolinite, and chlorite clay minerals associated with coarse fractions was transported to the Canada Basin primarily in relation to the existence of large ice sheets in northern East Siberia during glacial periods. Radiogenic isotope signature in upper Quaternary records from the Mendeleev Ridge also indicates that the Okhotsk-Chukotka volcanic rocks provided one of the principal end members, especially during MIS 4 and 6 (Fagel et al, 2014;Bazhenova et al, 2017). This sediment had to be transported into the Arctic Ocean directly from the East Siberian/Chukchi margin as the alternative pathway via the Bering Sea only operated at high interglacial sea levels, when the Bering Strait was open for throughflow (e.g., Keigwin et al, 2006;Ortiz et al, 2009).…”