Application of fractal theory in ore formation by breccia and hydrothermal deposits

Using fractal theory, the relations between ore formation by breccia and hydrothermal deposits are setup in order to study the features of ore formation, breccia and rock fracture. The analysis and studies show that the main reason of ore body controlled by contact belt is not by the developing skarn rock. The contact belt is the lithologic change belt of great difference or the sudden transition belt of physical and chemical environment. It is also the weak zone of structural deformation and the area of stress concentration. The interaction in contact belt by structural stress and fluid pressure will lead to rock fracture, which can produce local fluid pressure field and cause the ore fluid aggregation to the fractural area during ore formation. Meanwhile, the process will provide a good way for ore deposit and accelerate the fluid-rock chemical reaction leading to the mineral solution and precipitation. It is concluded that those actions above need dilatants, open and tensioning space. The rock fracture in the contact belt has the features to closely locate the ore formation. From the analysis by fractal theory, the center of rock tension fracture is the dilatants center where the energy input can reach the maximum. The more the energy inputs, the easier the fractural dilatants are and the ore fluid is aggregated and formed.