Submarine landslides in Arctic sedimentation: Canada Basin

Canada Basin of the Arctic Ocean is the least studied ocean basin in the World. Marine seismic field
programs were conducted over the past 6 years using Canadian and American icebreakers. These expeditions
acquired more than 14,000 line-km of multibeam bathymetric and multi-channel seismic reflection data
over abyssal plain, continental rise and slope regions of Canada Basin; areas where little or no
seismic reflection data existed previously. Canada Basin is a turbidite-filled basin with flat-lying
reflections correlateable over 100s of km. For the upper half of the sedimentary succession, evidence
of sedimentary processes other than turbidity current deposition is rare. The Canadian Archipelago
and Beaufort Sea margins host stacked mass transport deposits from which many of these turbidites
appear to derive. The stratigraphic succession of the MacKenzie River fan is dominated by mass
transport deposits; one such complex is in excess of 132,000 km2 in area and underlies much of
the southern abyssal plain. The modern seafloor is also scarred with escarpments and mass failure
deposits; evidence that submarine landsliding is an ongoing process. In its latest phase of
development, Canada Basin is geomorphologically confined with stable oceanographic structure,
resulting in restricted depositional/reworking processes. The sedimentary record, therefore,
underscores the significance of mass-transport processes in providing sediments to oceanic abyssal
plains as few other basins are able to do.