Geological characteristics and fluid inclusions of Huanren skarn polymetallic deposit

Huanren skarn polymetallic deposit,hosted by skarn contact belt between Cambrian limestone and late Yanshanian diorite complex,is located in conjuction of northern part of Liaodong Rift and Taizihe Depression.Typically,skarn minerals are characterized by two main alteration styles: early prograde assemblage and later retrograde assemblage,and there is an obvious change in ore elements from Fe→Cu(Mo) to Zn→Pb upwards.In order to understand physicochemical properties and evolution history of ore-forming fluids,vapor-liquid fluid inclusions from garnet and calcite were studied.The data show that temperatures of homogenization for garnet fluid inclusions range from 376.1 to 450.0 ℃,with an average of 411.6 ℃;whereas those for calcite fluid inclusions range from 122.6 to 170.0 ℃ and 178.3 to 270.2 ℃,with averages of 149.5 ℃ and 204.5 ℃ respectively.Temperatures of final ice melting range between -4.2 and -17.6 ℃.All data we determined are consistent with those of former researcher and are of theoretical and practical significance in comparison with that of other skarn deposits.Based the above,we proposed that ~410 ℃,400~300 ℃,~150 ℃ and ~200 ℃ are main ore-forming temperatures of Fe-Cu(Mo),Cu-Zn and Zn-Pb ore bodies,respectively.Old Pb,S and D-O geochemical data and new REE data indicate that magmatic fluid originates in the upper mantle and carries 2010 年 plentiful ore-forming materials in migration,meteoric water may be involved during later skarn retrograde stage.