Chemical reaction patterns due to fluids mixing and focusing around faults in fluid-saturated porous rocks

Abstract: Chemical reaction patterns are strongly dependent on flow rates, solute diffusion/dispersion and chemical kinetics. Since ore body formation is closely associated with chemical reaction patterns, it is important to investigate an interaction between solute advection, solute diffusion/dispersion and chemical kinetics due to two fluids mixing and focusing around faults in fluid-saturated porous rocks. Therefore, the concept of the equilibrium length due to either solute advection or solute diffusion/dispersion is presented. For a permeable fault with a given chemical reaction, there exists an optimal flow rate so that chemical equilibrium may be attained between two fluids mixing and focusing within the fault. However, for rapid and parallel flows, such as those caused by the lithostatic pressure gradient, it may be impossible for a chemical reaction to reach an equilibrium state within a permeable vertical fault, if two fluids are not well mixed before entering the fault. [Copyright &y& Elsevier]