Anatexis and metamorphism of the oceanic crust at the amagmatic axis in Northern Mariana Trough

Abstract

Series of high P-T melting experiments of amphibolite were carried out at 900-1200°C and 0.3-0.7GPa to understand the origin of felsic plutonic rocks in the northern Mariana Trough. The present data suggest that andesitic melts chemically similar to the Mariana Trough felsic plutonic rocks can be produced by anatexis of hydrous basaltic materials at ∼0.15 GPa and ∼1000°C. We develop the petrogenetic model for the plutonic rocks in the northern Mariana Trough.