Numerical modeling of intraoceanic arc growth

We investigate crustal growth processes on the basis of a 2D coupled geochemical—petrological-thermomechanical numerical model of retreating intraoceanic subduction. The model includes spontaneous slab retreat and bending, subducted crust dehydration, aqueous fluid transport, mantle wedge melting, and melt extraction resulting in crustal growth. Our numerical experiments show that (1) the rate of plate retreat influences both the rate of crust formation and composition of newly formed crust; (2) both the intensity of melt extraction and the age of subducted plate affect the volume of newly formed crust. In the present paper we describe possible scenarios of magmatic and geodynamic evolution of the arc system and then compare results with magmatic addition rates of Western Pacific arcs. Published in Russian in Vestnik Moskovskogo Universiteta. Geologiya, 2009, No. 4, pp. 30–43. The text was submitted by the authors in English.