Effect of Quartz Deposition on the Dynamics of Magma Chamber Degassing

Abstract

The filtration of a supercritical brine flow during the magma chamber degassing is numerically simulated with consideration of quartz transport and deposition. It is shown that the quartz deposition and the accompanying decrease of permeability reduce the size of the concentrated brine lens formed above the magma chamber. The effect of rock hydraulic fracture on the lens formation is studied. An unsteady degassing regime is revealed; this regime is associated with a periodic increase and decrease in permeability due to the hydraulic fracturing and quartz deposition. The obtained numerical results are in agreement with the geological data on the structure of copper deposits.