Abstract:Coupling Tectonic-fluid Metallogenic Model for Sandstone-type Copper Deposit in the Chuxiong Basin, China HAN Run-sheng1), ZOU Hai-jun1), WU Peng1), FANG Wei-xuan2), HU Yu-zhao1), (1.Faculty of Land and Resource Engineering, Kunming University of Science and Technology; South-West Institute of Geological Survey, Geological Survey Centre for Nonferrous Metals Resources, Kunming 650093; 2. Geological Survey Centre for Nonferrous Metals Resources, Beijing 100012) Sandstone-type copper deposit is the typical one of ore deposit species in the continental red-bed Chuxiong Basin, China. In the dynamic evolution processes of tectonic-fluid-mineralization system, the formation of the kind of deposits experienced 3 periods, which were sedimentation-diagenesis metallization, reformation metallization, and late faulting process. ‘coal-copper-salt’ three-colors sediment formations and basin fluid were formed in the Middle-Late Yanshan Period; With the tectonic-thermal evolution, fold traps basin fluid was formed in Early Himalayan Period. Cu-bearing fluids from basin basement ascended along contemporaneous fault, and carried chalcophile elements from deep-seated to coal seam. It resulted in the formation of Cu-bearing reductive fluid [H2O-SO2-CO2-CH4(C3H8-C2H6)-HSO4--HCO3-] which ascended along secondary faults, buried faults, interlayer faults and deformation band of axial plane. High salinity and oxidative fluid (H2O-SO2-CO2-N2-CO-HSO4-) formed by deep cycle meteoric water leaching gypsum bed. The two type fluid that closed in higher porosity and permeability sandstone reservoirs encountered in sandstone and shale and associated with water-rock interaction, then stratiform and stratoid ore bodies which hosted in middle-fine sandstone could formed in flank and core of folds or interformational faults; Tectonic reworking again, vein ore bodies or mineralization formed in the secondary faulting zone in the Middle Himalayan Period. The deposit formed from an outcome that fold closed basin fluid, structural fissure and ore-bearing facies closed ore-forming fluid. It was a coupling among the ore source, controlling tectonic and ore-forming fluid. In terms of this analysis, the deposit distribution with fold and ore-bearing strata, mineral and elements zoning were interpreted. A coupling model of tectonic-fluid metallogenesis for sandstone-type copper deposit in Chuxiong Basin has been established. Key words: Deposit Model; Tectonic-fluid Coupled Metallogenesis; Sandstone-type Copper Deposit; Chuxiong Basin ,China