ARC-ARC COLLISION BY THE EXAMPLE OF THE ALEUTIAN AND KAMCHATKA ISLAND ARCS
A.I. Kozhurin1,2, T.K. Pinegina1
1Institute of Volcanology and Seismology of Far Eastern Branch of the Russian Academy of Sciences, Petropavlovsk-Kamchatsky, Russia
2Geological Institute of the Russian Academy of Sciences, Moscow, Russia
Keywords: Kamchatka, Aleutian Arc, arc-arc collision, active faults
Abstract
This article presents data on active fault-related deformation of the Kamchatka Peninsula (Kamchatka, Russia), located between the converging Aleutian and Kamchatka Island arcs. It is shown that convergence of the arcs results in shortening of the Earth’s crust of the Kamchatka Peninsula in a direction transverse to the peninsula. The convergence is accomplished by underthrusting of the colliding blocks: the Aleutian Arc is underthrusting beneath the Kamchatka Peninsula, and the Kamchatka Peninsula is, in turn, underthrusting beneath Kamchatka. It is demonstrated that this mode of convergence is also characteristic of larger-scale collision zones, as in case of those between the Indian and Arabian plates with the Eurasian Plate. In all cases, the plate (block) that underthrusts is the one whose hinterland contains the driving source of motion.
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