Comparative Geodynamics of Aleutian and Izu–Bonin–Mariana Island-Arc Systems

Abstract

We have performed a comparative analysis of geological structure and geodynamic evolution of the nearly synchronous Izu–Bonin–Mariana and Aleutian island-arc systems. The first of these is included in a system of marginal island arcs of the western Pacific Ocean, and the second is intercontinental and situated between of Eurasian and North America continental plates. The both island-arc systems make up the independent Philippine and Beringia minor lithospheric plates. As has been shown, the Izu–Bonin–Mariana system arose from the geodynamic interaction of exclusively marginal oceanic plates, including marginal marine plates involved in Pacific subduction. The Aleutian system formed at the initial stage due to separation of part of the Cretaceous crust of the Pacific and as a result of subsequent processes within the island-arc system related to geodynamic movement of the North American and Eurasian continental plates in combination with oblique subduction of the Pacific Plate.