MODELING OF SUBDUCTION PROCESSES

On the basis of the laboratory experiments, geological and geophysical data available, a model is presented for subduction zone, including a relatively low-viscous layer (h), crust (k), heated to melting temper ature, and a melting zone, with diapir formed at its boundary. A theor etical solution is obtained to the problem on the heating zone of the (h + k) layer to melting temperature, and conditions are determined, u nder which volcanism exists in the subduction tone. Given that the mel t amount corresponds to the amount of the subducted crust matter (h k), we have obtained a criterion equation to characterize conditions o f volcanism origin. The rate of diapir uplift and parameters of the di apir-feeding conduit are estimated.