Numerical modelling of ore-forming dynamics of fractal dispersive fluid systems

Based on an analysis of the fractal structures and mass transport mechanism of typical shear-fluid-ore formation system, the fractal dispersion theory of the fluid system was used in the dynamic study of the ore formation sys tem. The model of point-source diffusive illuviation of the shear-fluid-ore formation system was constructed, and the numerical simulation of dynamics of the ore formation system was finished. The result shows that: (1) The m etallogenic system have nested fractal structure. Different fractal dimensi on values in different systems show unbalance and inhomogeneity of ore-form ing processes in the geohistory. It is an important parameter to symbolize the process of remobilization and accumulation of ore-forming materials. Al so it can indicate the dynamics of the metallogenic system quantitatively t o some extent. (2) In essence, the fractal dispersive ore-forming dynamics is a combination of multi-processes dominated by fluid dynamics and supplem ented by molecule dispersion in fluids and fluid-rock interaction. It chang es components and physico-chemical properties of primary rocks and fluids, favouring deposition and mineralization of ore-forming materials. (3) Gold ore-forming processes in different types of shear zones are quite different . (1) In a metallogenic system with inhomogeneous volumetric change and inh omogeneous shear, mineralization occurs in structural barriers in the centr e of a shear zone and in geochemical barriers in the shear zone near its bo undaries. But there is little possibility of mineralization out of the shea r zone. (2) As to a metallogenic system with inhomogeneous volumetric chang e and simple shear, mineralization may occur only in structural barriers ne ar the centre of the shear zone. (3) In a metallogenic system with homogene ous volumetric change and inhomogeneous shear, mineralization may occur in geochemical barriers both within and out of the shear zone.