Modeling the dynamics of sublimation of fractured rocks in the lithospheric mantle wedge beneath volcanoes of the Avacha group (Kamchatka)

Abstract

A quantitative analysis of sublimation of intensely fractured rocks in the mantle wedge was performed using a model of planar fracture channel. The use of dimensionless variables allowed us to analyze the influence of the Nusselt and Sherwood criteria on temperature and variation of the rates of dissolution of minerals and films on fracture walls and estimate both linear and mass sublimation rates. The results of this study predict relatively high rates of major element dissolution and remobilization by flows of magmatic and metamorphic gases over wide temperature range. Physical modeling of this process using natural mantle rock samples confirms the plausibility of the proposed model at least for the case of metamorphic-driven remobilization of elements from gas-liquid inclusions in metasomatized ultramafic rocks. This model provides a satisfactory explanation for the observed local heterophase alterations within ultramafic rocks that have experienced multistage deformation beneath volcanoes of the Kamchatka volcanic front.