Theoretical and numerical investigation into roles of geofluid flow in ore forming systems: Integrated mass conservation and generic model approach

Abstract

Mass and energy should be conservative in nature and ore forming systems within the upper crust of the earth are no exception. Thus, the mass conservation law is valid not only for a closed system, but for an open system as well. In the latter case, exchange between the system and its surroundings must be considered. Based on the mass conservation law, this paper considers a number of different roles of geofluid flow in ore forming systems. Due to the concurrence of these roles, interactions between fluid flow, heat transfer, mass transport and chemical reactions need to be considered in a comprehensive manner. Through theoretical analysis and computational simulations of several typical generic models for ore forming systems, it can be demonstrated that for an ore forming system in chemical equilibrium, the aqueous species of which are produced by the chemical dissolution reactions, the approximate form (i.e. the rock alteration index and the improved rock alteration index) of the mineralization rate can be used to predict mineralization patterns in the ore forming system. However, for a chemically non-equilibrated ore forming system, the detailed interaction between solute advection, solute diffusion/dispersion and chemical kinetics needs to be considered to determine potential mineralization patterns in the ore forming system.