The Tectonic Genetic Model Of Gold-bearing HydrofracturingBreccia Body And Control Of Gold Ore Body In The ShuangwangGold Deposit ,Shanxi Province

During the process of studying tectonic origin of Gold-bearing breccia bodies in the Shuangwang gold deposit ,Shanxi province, the author apply several modern tectonics theories, such as hydrofracturing, fluid dynamic breccia, tectonic pumping, deformation partitioning, embryonic fracture etc. The paper presents an kind of new model for the formation of hydrofracturing breccia-type metallotectonic, which is one of fracture-vein-breccia series metallotectonics concerning fluid, by deformation partitioning, embryonic fracture, hydrofracturing and rupture-healing.Based on the geological feature of Gold-bearing breccia bodies in the Shuangwang gold deposit ,Shanxi province, author identified it to be hydrofracturing breccia bodies, are formed by hydrofracturing of the deep-seated gold-bearing and alkali-rich fluids in the Devonian hydrothermal sodium-rich rock series. In the early period, the progressive cosxial compression caused the competent sodium-rich series and the uncompetent pelitic series to deform and partition, forming a lens-like weak-deformation domain distributed at approximate equidistance and a lineat srong-deformation zone respectively. Among them, the uncompetent pelitic series are cleaved in the srong-deformation zone with relatively high temperature, high pressure; With weak hydrofracturing, the competent sodium-rich series dilatacying and forming microfracture(ie,embryonic fracture) in the core of the weak-deformation demain,which is a natural lens-like pumping centre with relatively low temperature, low pressure and high permeability. In the late peroid, the progressive uncoaxial shear of right-lateral and high-angle oblique thrusting caused hydrofractuing along the most developed joints and fractures in the core of weak-deformation domain ,and linked up with deep fracture systems. The large pressure decline in the pumping centre caused the deeped-seated confined fluids to develop periodic tectonic pumping, hydrofracturing and precipitation healing in the sodium-rich rock series. The buried gold-bearing hydrofracturing breccia bodies predicted on the basis of the partitioning deformation tectonic type have been proved by drilling.