Finite element modelling of rock alteration and metamorphic process in hydrothermal systems

Abstract

AbstractWe use the finite element method to simulate the rock alteration and metamorphic process in hydrothermal systems. In particular, we consider the fluid–rock interaction problems in pore‐fluid saturated porous rocks. Since the fluid–rock interaction takes place at the contact interface between the pore‐fluid and solid minerals, it is governed by the chemical reaction which usually takes place very slowly at this contact interface, from the geochemical point of view. Due to the relative slowness of the rate of the chemical reaction to the velocity of the pore‐fluid flow in the hydrothermal system to be considered, there exists a retardation zone, in which the conventional static theory in geochemistry does not hold true. Since this issue is often overlooked by some purely numerical modellers, it is emphasized in this paper. The related results from a typical rock alteration and metamorphic problem in a hydrothermal system have shown not only the detailed rock alteration and metamorphic process, but also the size of the retardation zone in the hydrothermal system. Copyright © 2001 John Wiley & Sons, Ltd.