Fracture sealing by silica precipitation from geofluid:implication from hydrothermal experimant and modeling

Abstract

Dissolution and precipitation of silica minerals provides significant effect on hydrological properties within upper crust. In this research, We conducted hydrothermal flow-through experiments for silica precipitation under vapor and supercritical condition and observed internal structures by X-ray computer tomography. In both experiments, the significant silica precipitation within few days, but showed contrasting porosity structures. In vapor condition, fine-grained quartz crystals formed and settled on the vessel bottom, whereas in supercritical phase amorphous silica unformed precipitated. We also constructed numerical simulation of reaction - advection - adsorbed coupling model to approach a various natural setting.