The Behavior of Hydrothermal Mineralization With Spatial Variations of Fluid Pressure

Abstract

AbstractIt is assumed that variable fluid pressure states in space control the spatiotemporal evolution of hydrofracture, and their responses on mineralization. In this study, mineral precipitation caused by rapid fluid pressure reduction is incorporated into a cellular automaton model to explore the effects of various spatially structured fluid pressure rates on the behavior of hydrofracture and mineralization. We explore a range of spatial structures, which vary from essentially random to strong spatial structure. In the model, fluid pressure increase induces local hydrofracture to nearest neighbors, and fluid mass is conserved among the cell affected. As the model evolves, internally connected networks merge and a correlation length is established as the system approaches the failure condition and identifies the percolation threshold. The correlation length of the internally connected network scales with the degree of spatial structure of fluid pressure increase rates, resulting in earlier arrival to the percolation threshold for strong spatial structures. At the percolation threshold, large‐scale fluid pressure reduction induces mineral precipitation and facilitate the formation of the spatially structured geochemical patterns. The degree of spatial structure of geochemical patterns correlates with the spatial structure of fluid pressure increase rates because mineral precipitation from fluid pressure reduction occurs over larger scale. The proposed model offers an intuitive and potentially important tool for understanding the role of spatially structured fluid pressure increase and reduction on hydrothermal mineralization patterns in fault‐related ore systems.