G.P. Avdeiko1,2, A.A. Palueva1, O. A. Khleborodova1

Geodynamic model of alkaline basaltoids with intraplate geochemical characteristics was developed on the base of systematization and analysis their space and time data in the East Kamchatka volcanic arc. The alkaline «intraplate» rocks in the East Kamchatka were formed as a result of partial melting at low degree of an «andersonian» type mantle plume. This mantle plume was generated in the astenosphere beneath the Pacific plate about 400-500 km from the deep sea trench similarly Hirano et al. (2006) flexure model and then was moved to the new forming East Kamchatka subduction zone by mantle convection. Adakites were produced by partial melting of the frontal part of the subducting Pacific plate in the initial stage of subduction. The model explains a short time of the formation of alkaline rocks, and their change by transitional rocks and adakites, and then by typical calk-alkaline rocks, and their position only in the subduction zone jump to the present-day position.

Keywords: alkaline basaltoides, intraplate lavas, adakites, volcanism, geodynamics, evolution.