The Analysis Of Geochemical Characteristics, And The Genesis Of Ore Deposits In Tongshan Copper Deposit, Tongling, Anhui Province

The Tongshan copper deposit is located on the northwestern margin of Yangtze Craton in Tongling,Anhui, which is a important copper polymetallogenic belt of Middle-Lower Yangtze Valley. Although many works and studits have been done, there are some aspects that are studied further more, such as the positioning mechanism of mineralization and the genesis of ore deposits. Based on the dissecting the representative deposits in detail and employing the classical theory and methods of Skarn copper deposit, this thesis has been studied on the geological characteristics, geochemistry, ore-controlling factors, the positioning regularity of mineralization and the genesis of ore deposits. The main achievements are made as follows:1.By analyzing the regional geological setting of ore-forming processes and the geological characteristics of deposit, The metamorphism and alteration include the thermal metamorphism, contact metasomatism, brecciation and hydrothermal alteration mainly;Copper mineralization and sulfur mineralization related with the garnet Skarn, copper mineralization and iron mineralization related with the diopside Skarn,potassium and silicide related with copper mineralization; According to the mineral association, divided the metallogenesis of the copper deposit into three periods and five stages.2.By researching the characteristics of the rock and mineral geochemistry, we recognized that the rock mass stemmed from the upper mantle and has withstood the assimilation of Crust. The ore-forming fluids come from the magma mainly, mixed the later period atmospheric precipitation.3.Discussed the relation between the stratum,the structure, the magmatic rock and ore-forming, the stratum showed favorable lithology, lithologic surface of discontinuity and ejective shielding function; the structure controlled the intrusion of magma,the formation and location of rock-forming and orebody;the magmatic rock offered the metallogenic materials.4.By studying the positioning mechanism of mineralization and the genesis of ore deposits comprehensively,the metallogenic model that is homologous multi-period has been established, which show Tongshan copper deposit is a typical Cu-Fe-Au-S Skarn deposits, but is overlapped by the porphyry copper-molybdenum mineralization and hydrothermal Cu-Fe-Pb-Zn-Ag mineralization partially...