The mechanics of hydrothermal systems: II. Fluid mixing and chemical reactions

摘要: Abstract In the accompanying paper, Part I, hydrothermal mineralising systems are considered as open chemical reactors that operate far from equilibrium to develop an exothermal alteration system with veining and brecciation, followed by competition between endothermic mineralisation exothermic mineral reactions. this sequel we examine interplay of these processes fluid transport impact upon deposition. Chemical reaction flow in porous media admit two distinct mechanisms which result significantly accelerated mixing. First, gradients physical parameters such potential, density surface tension generate instabilities form fluid/chemical mixing machines propagate front. Second, so-called chaotic advection , a behaviour particles follow trajectories, arises inherently Stokes networks complexity pore geometry. For length-scales greater than ~ 1 mm, enhance hence metal/sulphide Furthermore, can also alter qualitative characteristics stability or speciation non-equilibrium reactions, significant implications for enhanced rates. Such interactions deposits multifractal spatial signatures similar those observed field. render distributions non-ergodic fact process based geostatistics must take into account.