Abstract:

There are very abundant natural resources, especially the oil, gas and coal in the Arctic Ocean and surrounding shelf seas. But a very few geological and geophysical survey has been finished in the area, due to the rigorous natural conditions. Many issues are still controversial. The main knowledge for the tectonics in the area is based on the aeromagnetic survey. It is tried to review for the tectonic features of Arctic Ocean in this paper. The first, the tectonic features of Eurasian Basin and its evolution is most uncontroverted due to the typical linear magnetic anomalies. The Basin opened from the period of linear magnetic anomaly 25, about 58Ma, and after linear magnetic anomaly 13, about 35Ma, Yermak Plateau broke from Morris Jesup Rise and it makes the Arctic Ocean linking to the North Atlantic. The secondly, the crust beneath Alpha Ridge and Mendeleev Ridge should be continental, similar with the Lomonosov Ridge, according to their crustal structure and thickness. It is possible that both of the Ridges broke from the Eurasian shelf. The thirdly, the crust beneath Makarov Basin is typical oceanic, but its revolution is fewer constrained. One of the main opinions about it is that it was formed by spread from Cenomanian to early Eocene, and declined by development of Gakkel spread center. The fourthly, as oldest basin in Arctic Ocean, the forming of Canadian Basin is poorly understood. But it is presumed that the basin was forming in a period between 140~135Ma to 95~80Ma, as New Siberian-Chukchi-Alaska microplate rifting from Canadian Margin in “wind screen wiper” fashion. The fifthly, the tectonic revolution of Arctic and adjacent area includes 3 phases: Late Jurassic-Early Cretaceous, Late Cretaceous-Early Cenozoic, and Cenozoic. Phase Ⅰ is determined by the formation, evolution, and extinction of the spreading center in the Canada Basin, while Phase Ⅱis connected to the development of the Labrador-Bafin-Makarov centers branch and phase Ⅲ pertains to the formation of the spreading system of ultraslow Mohna, Knipovich, and Gakkel mid-ocean ridges that has functioned until now in the Norwegian-Greenland and Eurasia basins.

Key words: Tectonic revolution