Late Quaternary paleoenvironmental changes revealed by multi-proxy records from the Chukchi Abyssal Plain, western Arctic Ocean

• Published in: Global and Planetary Change
• Main Authors: Wang, R., Xiao, W., Marz, C., Li, Q.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier Science BV 2013
• Subjects: IRD provenance; terrigenous input; surface productivity; Nps-δ18O and -δ13C; Nps-Mg/Ca; late Quaternary; Western Arctic Ocean; Arctic; Arctic Ocean; Canadian Arctic Archipelago; Chukchi Shelf; Chukchi Abyssal Plain; Arctic Archipelago; Chukchi; Foraminifera*; Ice Sheet; Iceberg*; Neogloboquadrina pachyderma; Planktonic foraminifera; Sea ice
• Online Access: http://hdl.handle.net/2440/79976; https://doi.org/10.1016/j.gloplacha.2013.05.017

Late Quaternary paleoenvironmental changes in the western Arctic Ocean are revealed by multi-proxy records of core 03M03 from the Chukchi Abyssal Plain (CAP). Proxy parameters include lithology, grain size fractions, and mineralogy and petrology of ice-rafted detritus (IRD), element contents, biogenic components, δ18O, δ13C and Mg/Ca of planktonic foraminifera Neogloboquadrina pachyderma (sin.) (Nps). Seven IRD (>250μm) peaks are interpreted as marking detrital input by rafting sea ice or icebergs during MIS 3 interstadials and early MIS 1. High MnO, CaO and MgO contents and high Ca/Al and Mg/Al ratios during MIS 3 and MIS 1 correspond to increases in ice-rafted detrital carbonates and the synchronous declines in siliciclastic elements (e.g., Al2O3, Fe2O3). Therefore, these warmer periods were characterized by a high detrital carbonate input entrained in icebergs from the Canadian Arctic Archipelago coeval with an increased input of Mn through rivers and/or coastal erosion. Relatively stable contents of siliciclastic elements and their ratios in the grayish sediment units are interpreted from turbid surface water plumes or nepheloid flows delivered by meltwater and/or brine rejection from ice-sheet margins at the Arctic Ocean periphery. Relatively stable clay- and silt-sized fractions were attributed mainly to sea ice entrainment over glacial-interglacial cycles. High foraminiferal abundances in the brown units during MIS 3 and 1 are related to enhanced calcareous plankton productivity under more open water conditions and/or the incremental input of Atlantic water masses. Relatively high TOC and opal contents in the grayish units of MIS 3 appear to have accumulated by lateral transport of organic matter from the Chukchi shelf to the deep abyssal plain. Lower contents of biogenic material in the brown units probably result from increased dilution by rapid IRD deposition, and from early diagenetic degradation. Depletions in Nps-δ18O and -δ13C concurrent with high foraminiferal abundances and IRD peaks within ...