Sedimentary processes within the Canadian Arctic Archipelago:
relationships among sedimentological, geochemical and magnetic sediment
properties
Abstract
The sedimentological, geochemical, physical and magnetic properties of
40 surface and basal sediment samples of box cores collected throughout
the Canadian Arctic Archipelago (CAA) from the Canadian Beaufort Shelf
to Lancaster Sound were analyzed to determine the sedimentary processes
that operate within the CAA during the pre- and post-industrial periods.
In addition, the chronology of seven selected regional cores was
established using 210Pb measurements, where the base
is dated between 1550 and 1820 CE. These cores provide an opportunity to
robustly compare post-1900 sedimentary conditions with those of the
colder Little Ice Age period (LIA; ~1500-1900 CE). The
different properties combined with multivariate statistical analyses
result in the identification of three regional provinces with distinct
sedimentary characteristics: (1) the West province (the Mackenzie
Shelf/Slope, West Banks Island and the M’Clure Strait) typified by
detrital associations (Fe-Rb-Ti-Zn), high organic matter inputs,
dominance of magnetite and low-coercivity minerals and high
aluminosilicate contents; (2) the Intermediate Zone (the Amundsen and
Coronation Gulfs) distinguished by Si-Al-Zr-Sr-K associations, Fe-Mn
oxyhydroxyde precipitation and a mixture between marine and terrigenous
organic matter; and (3) the East Province (the Queen Maud Gulf, Victoria
and Barrow Straits, and Lancaster and Eclipse Sounds) described by high
detrital carbonate inputs, marine organic matter, and dominance of
high-coercivity minerals. Our results confirm that the pre- and
post-industrial 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.