Geochemical and physical, sedimentological and magnetic properties of sediments collected throughout the Canadian Arctic Archipelago during the CCGS Amundsen cruise AMD16

Sedimentological, geochemical, physical and magnetic properties of 40 surface and basal sediment samples of box cores collected throughout the Canadian Arctic Archipelago from the Canadian Beaufort shelf to Lancaster Sound were analyzed in order to determine the modern and the Little Ice Age (LIA) sedimentary processes. The chronology of seven selected regional cores was established using 210Pb measurements, where the base is dated on average at ~1600 AD. The different properties combined with multivariate statistical analyses have resulted in the identification of three provinces with distinct sedimentary characteristics during both periods: (1) The West province (Mackenzie Shelf/Slope, the West Banks Island and the M'Clure Strait) typified by detrital associations (Fe-Rb-Ti-Zn), important organic matter inputs, dominance of magnetite and low coercivity minerals and higher alluminosilicate contents; (2) The Intermediate Zone (Amundsen and Coronation Gulfs) distinguished by Si-Al-Zr-Sr-K-Y associations, Fe-Mn oxyhydroxyde precipitation, constant high magnetic grain concentration and a mixture between marine and terrigenous organic matter; (3) The East Province (Queen Maud Gulf, Victoria Strait and the Barrow/Lancaster Sound) described by high detrital carbonate inputs, marine organic matter, a dominance of high coercivity minerals and higher magnetic concentrations especially during the LIA. Our results confirm that the recent sedimentary dynamics are controlled by sediment supplies from the river discharges in the West and Intermediate Provinces whereas the East province is more influenced by sea-ice and coastal erosion. Sedimentary processes during the LIA suggest intensification of the Mackenzie River runoff, sea ice conditions and consequently of sediment transport by the latter.