| Danba Yanzigou gold deposit is located in Songpan-Ganzi orogenic belt, Danba spondylolisthesis-superimposed thrust deep tectonite-chip, the main ore body occurs in the moderately-weakly metamorphosed slate, phyllite of the fourth petrofabric of the Devonian Wenguan group,and Yanzigou gold deposit is orogenic gold deposits.Based on Predeeessor's work,the author gathered geologic information,made field investigation, Data collection and laboratory analysis.With the help of theories of structural geology, petrology, mineral deposit geology, geochemistry, structure of ore field, obtains from the geotectonic background, focused on the relationship between stratigraphy, tectonics, igneous rocks and mineralization. Analysis the tectonic evolution, geological features and a variety of ore-controlling factors of mine,to proof the relations of space and time of structure and mineralizes, summarized the regularity of ore formation and structure mineralization model.The research shows that the the formation of gold strictly controlled by the structure. According to the different parts or form of structures, the ore can bedivided into quartz vein gold ore and carbonaceous slate type layered gold ore which has a dense network of quartz veins and pyrite. metallogenic evolution of the deposit is divided into,hydrothermal stage,supergene stage.and six periods.In the long process of geological evolution, Danba region has experienced complex tectonism of transgression history before Triassic,and in the late Indo-Chinese epoch, began a large-scale regional fold and thrust orogenic orogeny. through the early north-south squeeze and east-west compression of late, in the area dome structure and the NW-SE trending faults very develop,they form the structural framework in this area with EW trending,NE-SW trending subsidiary fracture and bedding ductile shear zone of mine.Deposits in this area with multi-cycle, multi-periods mineralization characteristics, principal factor of migration, precipitation and concentration of ore-forming fluid is structure, there is close relationship between deformation, transformation of structure and migration of ore-forming fluid, The "fault valve-Seismic pump" metallogenic mechanism of deposit structure also is the important factor of gold deposit formed.The source of metallogenic material are wall rock and deep hydrothermal.Structural ore-control characteristics of Danba Yanzigou gold deposit:three groups regional fracture of NW-SE trending, NE-SW trending, EW trending and dome structure composed the ore conducting structure,control of the mine area with the formation, evolution and spatial distribution; The tectonic framework of the mining area are Secondary fracture of EW trending,and complete a set with subsidiary fracture of subsidiary fracture SN trending, EW trending, NE-SW trending and bedding ductile shear zone,show the hierarchy and regularity of ore-control structure. Tensile subsidiary fracture of EW trending, NE-SW trending and bedding ductile shear zone are ore blending structure of mine.the small imbricate fault which formed in late of Yanshanian stage staggered near-bedded orebody, breaking the contiguity of orebody. |
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