Ore-formign Condition And Prosepecting Prediction Of Gold Deposit In The Laohugou-Dachaoyanggou Area,Fumeng County,Liaoning Province

The geotectonics of study area is located in the eastern part of Yanshan fold belt of northern margin of North China,transition part between Liaoxi depreddion belt and Beizhen uplifted zone,which belong to northeast part of Fuxin gold concentrated are of Yanshan intracontinent orogenic belt.It is transition section between EW-trending Weichang-Chifeng-Fuxin Au-Ag-Cu metallogenic belt and NE-trending Suizhong-Jinzhou-Fuxin Au-Pb-Zn-Mo metallogenic belt.The study area experienced formation of North China Craton crystalline basement,evolution of Craton cap and Mesozoic intracontinent orogenic belt.The complex and regular tectonic controlled development and distribution of gold deposit in the study area.According to research on characteristics of geophysics,geochemistry and ore genetic type,we analyze the ore-forming condition,and summarize porospecting indicator,and establish prospecting model,and finally delineated ore-forming prospecting area.Progress obtained by above research is as follow.There are three genetic types in the study area.The ductile shear belt type deposits are represented by Paishanlou and Jinjiadian gold deposits.The shear zone type depsits are represented by Dayingtaogou and Laohugou gold deposits.The magmatic hydrothermal-type deposits are represented by Dachaoyanggou and Hongtugou gold deposits.The study area can be divided into two tectonic metallogenic belts,gold-oriented north part of Dawujiazi-Bajiazi zonal metallogenic belt,and Lushan uplifted metallogenic belt in the southeast part of Fuxin.The gold deposits occurred within external contact zone wall rock,and maily on fracture and filling mineralization.Some of deposits occurred within margin of rock body and contact zone,and mainly on veinlet-disseminated mineralization.The alterated rock and crushed zone alterated rock type deposits are controlled by Archean Jianping Group Waziyu Formation,which is composed by amphibolites,secondly Jianping Group Dayingzi Formation,Xiaotazigou Formation.The best prospecting area is transition part of multigroup tectonic,interlayer fracture zone.The magmatic activity in the study area is play role in formation of gold deposit.The Yanshanian magmatic acitivity pass into granitic magma-fluid system,which lead to distribution of gold deposit is associated with distribution of granite.The alternated mylonite zone is the best place to prospecting deposit.There is zoning in the alternated mylonite zone,the zone is fade zone-beresite zone-silicification-carbonatation zone.The element association of Au,Cu,Pb,Zn,As and Sb is the best indicator to prospecting deposit.The gold deposit is occurred in high-intensity magnetic field or transitivity magnetic field,and gravitational field is G gravity negative field.The circle tectonic is the benefit ore-forming condition,and reflect the existence of concealed orebody and tectonic.Combining ore-forming regularity and prospecting indicator,the study area can be divided into two metallogenic prospect and five gold mineralization concentrated area.Ductile shear zone-Paishanlou-Dayingtaogou gold metallogenic prospect.Magmatic hydrothermal-Jiamusu-Luotuoshan gold metallogenic prospect.