Ore-Controlling Fracture Mechanism Of Vein-Type Tungsten Ore Deposits In Dajishan Jiangxi Province Of China

Fragmentation can be seen in various materials, and it happens at different scales. Recent researches indicate that the earth material will crack along the existing weak zone of different scaling and its fracture shows a hierarchical structure, that is to say, the fracture under macroscopic scaling is the consequence of accumulation of smaller scaling fracture. The amount of previous results shows that the cumulative frequency distribution of fragment size is similar to power-law distribution. A power-law distribution of fragment size indicates that fragmentation possesses a scaling law, namely fractal theory of fragmentation. This work studies the famous "five-storeyed" morphological vertical zonation of the vein-type tungsten ore deposits in Huangsha and Dajishan of Southern Jiangxi Province from theoretical analysis and acoustic emission experiment. The ore-controlling multiple fractures of vein-type tungsten ore deposits is radiated and gradually bifurcated into hemispheric morphological distribution in three-dimensional space, and belong to the local structures completely different from geologic structure framework of region and ore region. The ore-controlling multiple fractures of the vein-type tungsten ore deposits are heat-induced and fluid-driven fractures dominated by hydraulic fracturing. The "five-storeyed type" morphological vertical zonation of the vein-type tungsten ore deposits is the consequence of fractal dilatation of multiple hydraulic fracturing. The self-organized criticality of the vein-type tungsten ore deposits is the origin of multiple fractal dilatation, while the steepest gradients of hydraulic stress field around the tip of mesoscopic cracks is the driving force of fractal dilatation.