Geological Characteristics And Genesis Of The Dingjialing-taiyangping Gold Metallogenic Belt

The Dingjialing-taiyangping gold metallogenic belt locates the Mao county group. Ore area is located in the Huangping formation of upper Silurian System. The protolith has the character of turbidite. In the middle piece of the huangping formation, the gold content is clearly over the upside and the downside. It is central part of ore horizon.The Dingjialing-taiyangping gold metallogenic belt is controlled by the structure of ductile-brittle shear zone, along NE trenching, and have the character of multiphases and polystages. Ductile-brittle shear zone is the main ore-forming and ore-controlling factors in The Dingjialing-taiyangping gold metallogenic belt,ductile-brittle shear action is the main dynamic origin of ore-forming in studying field.Bying a lot of work study,we can divide structure-forming into three phases, that is, pre-enrichment stage of ore-forming sediment,shearing structure and hydrothermal reformation stages, surface evolvement stages.We have made some researches to analyse and test the fluid inclusions and the stable isotopes in this area, The research indicates that ore-forming fluids has repetitious character during 144℃～414℃. The conformation of gold mine exists two portions. 300℃～390℃basically is corresponding with the first time of ductile-brittle shear deformation–structural hydrothermal differentiation metallogenic period, 180℃～280℃basically is corresponding with the second time of brittle shear deformation–structural hydrothermal differentiation metallogenic period. The research of S isotope in the gold deposit indicates that the origin of the mineral is very single.It is concerned with the quality of the rock. The content of sulfur is from the host rocks, The research of Pb isotope indicates the ore-forming backdrop is collision-compression orogeny between Yangtze platform and Yudongzi-terrane block, the effect of orogeny renders the mineral substance of the rock. differentiation, activation, finally expands in the advantageous mineralization allows the structure spot precipitation to concentrate. The element of Pb isotope is resemble to the element of Pb isotope in the Dongbeizhai gold deposit. It explains the ore-forming source rock belongs to the Silurian stratigraphy. The composion of H-O isotope indicates ore-forming fluids is the structural water.By studying geology and geochemistry of deposit, we can draw a conclusion about the metallogenic model: ore-forming matters origins wall rocks, during ore-forming sediment stage happen pre-enrichment; the effect of ductile-brittle shear renders the mineral substance of the rock differentity and activaty; ore-forming fluid is the structural water, with enough ore-forming to contains, ore-forming fluid migrate along the ductile-brittle shear zone to the earth's surface, finally expands in the advantageous mineralization allows the structure spot precipitation to concentrate. the supergene oxidation and weathering leaching also are important for gold enrichment.