摘要
The physical and chemical conditions of ore-forming are controlled by detachment zone, of which shear fracture of brittle rock on top system provides channel for downward migration of the deep-cycle of underground water. Abnormal thermal gradient provides heat for cycle of the fluid, so that it can set up a circulatory system which is connected to precipitation and owes oxidizing environment. Some of the fluid from retrograde metamorphism of detachment fault footwall rocks and mylonite zone, together with hydrothermal from magma, form hydrothermal circulatory system of the footwall restore environment at the shielding of the mylonite, schistosityzone fragmentation rocks or impermeable rocks. Ore-forming components scattering in bedrock are extracted by hydrothermal circulation of the two systems, precipitating on the oxidation-reduction interface at the vicinity of fault and forming planar-shaped abundance zone of gold, silver body. Because detachment fault plane is a undulating surface, planar-shaped gold, silver body may be not level, presenting small-angle fluctuations.
