Ore-forming Geological Conditions And Tectonic Background Of The Gold Deposit In Bengbu Wuhe

Shandong Zhaoyuan and Anhui Wuhe located in east and west sides of the famous fault-Tan-Lu fault zone,they have similar tectonic setting and metallogenic geological conditions and structure.But the former has developed into China's famous gold mine area,and developed super-large gold mine,while the latter is mostly small deposits,there have no obvious breakthrough in the search for large deposits so far,then restricting the local economic development.In view of the above,this paper based on a comprehensive and systematic collection,analysis,summarization and summary of the existing data,to construct the theory of mineralization as the guiding ideology,based on the geophysical survey,to geochemistry as a means to carry out the study and analyze of the metallogenic conditions of gold deposits in Wuhe Dagong mountain,and proved the ore-forming conditions such as ore-controlling rock,magmatic rocks,tectonics,ore-forming materials and metallogenic physicochemistry.It is found that the Nvshan rock mass exposed in the Dagong mountain area is controlled by the fault,and the invasion age is consistent with the metallogenic age.Mineralizing material of Au is from magmatic activity and Wuhe group metamorphic basement in Swire Pacific.The main trace and rare earth element analysis of metamorphic basement surroundings in Zhaoyuan are shown that,the Zhaoyuan's Jiaodong group metamorphic basement metamorphic rocks are composed of granite diorite with Na-rich,K-rich,calcium-alkaline series and aluminized-alumina,simlar with Wuhe's Xigu group.The fluid inclusions of Ore-forming quartz veins show that the ore-forming fluid is mainly CO₂ and NaCl salt solution,the salinity of the ore-forming fluid is 0.41¹5.06wt% Na Cleqv,the mineralization temperature is 265.8³66.1?,the mineralization pressure is74.37MPa¹00.82 MPa and the mineralization depth is 6.14km⁸.29 km.The metallogenic conditions of physical and chemical are similar to the Zhaoyuan gold deposit.From the Quartz vein ESR dating of Zhaoyuan and Dagong mountain,the ore-forming quartz veins are formed in the middle and late Early Cretaceous,the evolution of Mesozoic extension period fault in study area is divided into three stages:?1?Middle and late Early Cretaceous,eastern China mainly to stretch the fault,there are two main stretching effect;?2?Late Cretaceous to ancient century,the transformation of the tectonic system in the region is converted to the right-hand strike slip pull the role;?3?The Miocene,Sheet fault occurred in the Tan-Lu fault belt.Wuhe has a similar metallogenic potential with Zhaoyuan,and its formation is closely related to the extension period activities of the Tan-Lu fault zone.Guided by the theory of metallogenic lineage,Prove the metallogenic geological conditions and tectonic setting of the study area by compared with the metallogenic conditions of Zhaoyuan gold deposit.This results have a certain guiding significance for deep prospecting in Wuhe.