10. Canada Basin

Perennial sea-ice cover over much of Canada Basin of the Arctic Ocean has hampered geoscientific studies, but concerted efforts over the past decade– particularly with the use of two ice-breakers working collaboratively – has led to new seismic and sample acquisitions. These studies have revealed extensive non-oceanic basement beneath Canada Basin that coincides with proof of a central spreading axis and limited oceanic crust. Additionally, seismic reflection studies have shown its sedimentologic history and stratigraphic development. High resolution subbottom and multibeam detail have revealed its more recent geologic past, including the extent of ice margins during the Pleistocene and the role of submarine landslides and ocean currents within the basin. Despite this new information, there are still significant challenges in understanding the basin. These challenges result from the fact that the basin did not form by a simple rift/extension scenario, but rather more likely through a complexity of events that included variably oriented extension, trans-tension and transform tectonics. Additionally, emplacement of the high arctic magnetic domain (Alpha Ridge and Mendeleev Rise) masks underlying tectonic structures, and lack of age control inhibits correlation with global events.