The Canadian Basin (Arctic Ocean): Models of Its Geological Structure, History, and Geodynamics of Formation

The Amerasian and Eurasian basins are distinguished in the Arctic Ocean and are separated by the Lomonosov Ridge. The Canadian Basin, with Cretaceous oceanic and transitional crust, is located in the southern part of the Amerasian Basin. The Alpha-Mendeleev Rise and its associated deep-sea basins (Podvodnikov, Makarov, Toll, Nautilus, and Stefansson) lie to the north of the Canadian Basin. The Alpha-Mendeleev Rise and associated basins have continental crust that has been altered to varying degrees. Their major formation occurred about 125-90 Ma. We discuss three models for the formation of the Canadian Basin. Model-1: the entire Amerasian Basin with the oceanic and transitional crust was formed first (before 125 Ma). The Alpha-Mendeleev Rise region was then formed on the earlier oceanic crust as a volcanic formation (125-90 Ma). Model-2: the Canadian Basin formed first (before 125 Ma). The Alpha-Mendeleev Rise area and associated basins were then formed due to the significant transtension of the continental crust and magmatism (125-90 Ma). Model-3: The Alpha-Mendeleev rise area and associated basins formed first above a mantle plume (125-100 Ma). Subsequently, along one of the branches of continental rifting, spreading of the transitional and oceanic crust began and the Canadian Basin was formed (100-70 Ma). We find Model-1 to be the least probable, because it is now proven that the Alpha-Mendeleev Rise is underlain by continental crust. Model-2 and Model-3 are both possible. According to these models, the Canadian Basin formed as a backarc basin of the Pacific subduction zone.