Geological features and genetic analysis of Zhaishang gold deposit, Min county, Gansu

Zhaishang gold deposit lies on the south of Li-Min fore deep basin in the West Qinling,which is make up of the turbidite with the different lithology and granularity in the seabed slope fan envronment.Ore field is located in a group stratigraphic formation of Middle Devonian series.Rocks have the characteristics of high frepuency fold,which are make up of carbonaceous slate,sandstone,marlite orebearing rock seriea.We can conclude that Zhaishang gold deposit is controlled by the structure of ductilebrittle shear belt,along NWW-trenching,obliquity 30°-50°,and Have the character of multiphases and polystages.Ductile-brittle shear belt is the main ore-controlling factors in Zhaishang gold deposit.Orebearing wall rock have the weak hydrothermal alteration,mainly present disseminated,stringer veindisseminated arsenical pyritization,micro-stringer vein and stringer network vein siliconization,ankeritization,which are associate with Au.Ore structures have micro-disseminated,micro-stringer vein, congloeration disseminated,strawberry,and ore frames have automorphic-hypautomorphic granular, allotriomorphic granular,etc in late stage.Main industrial ore body occurs in the transition and alternation position of carbonaceous microclastic rocks and carbonaceous marlite,which are composed of two ore straps,southern,northern straps respectively.Northern ore strap is main industrial ore body,which have pyrite,pyrite-atsenopyrite,Sb-Au type gold ore;the main ore body is Cu-Au type gold in the southen strap.Above all,we can draw a conclusion:①we regard a group stratigraphic formation of Middle Devonian series as the ore source of Zhaishang gold deposit;② the ore-controlling structure of Zhaishang gold deposit is ductile-brittle shear belt,and it has the character of multiphases and polystages,which is the main ore-forming and ore-controlling factors;③ arsenopyrite and arsenobearing pyrite growth-bands is composed of the low arseno-breaing pyrite or arsen-opyrite in the kernel and the high arseno-breaing pyrite or arsen-opyrite growth-bands;.the gold deposit has character of low-middle temperature hydrothermal, we define Zhaishang gold deposit as calin-type gold deposit.