Geological Conditions Of The Gold Mineralization And Prospecting Direction In The Dongdao River Area,Dongfeng,Jilin

The Hengdao River is located at the China-North Korea Platform(Level I).Liaodong Tailong(Level II),Tieling-Jingyu Archway(Level III),The northern edge of the Lijia Block(Level IV),It is located in the south of Dongfeng County,Liaoyuan City,Jilin Province.The straight-line distance from Liaoyuan City is about 55 Km,and the straight-line distance from Dongfeng County is about 25 km.The administrative area is affiliated with Hengdaohe Town,Dongfeng County,Jilin Province,which is located in the Jizhong-Yanbian metallogenic belt and is an important prediction for the gold deposits in Jilin Province.Area.In this study,based on the regional geological background and geological characteristics of typical deposits(points)developed in the region,the ore deposit characteristics,ore-forming conditions,ore-controlling factors,and genesis of deposits were summarized,and combined with 1/50000 geochemical exploration anomalies in the area.The area adopts 1/10,000 geological surveys,1/10,000 soil geochemical surveys,geophysical surveys and ladder surveys,aeromagnetic surveys,and other physical and geochemical exploration methods to detect anomalies,narrow the prospecting target,and use trencher pairs.Abnormally high-value points and abnormal concentration centers are exposed on the surface to find new minerals and finally make a long-term assessment.The study area is located on the northwest side of Dunmi fault zone and has excellent metallogenic geological conditions.The exposed stratum is less and the lithology is relatively simple.The exposed strata only contain the Neo-Pacific representative of shell rocks and gray gneisses,Cretaceous sandstones,and a small amount of Quaternary loose deposits and alluvial deposits distributed along the valleys.The fault structure in the study area developed,and the fault structure after ore-forming controlled the distribution of ore bodies within the deposit,and the ductile shear zone developed in the area.The regional magmatic rocks are dominated by monzogranite,granodiorite and mylonitized granite,accounting for about 60% of the total area.In this study,the ages of monzogranite,granodiorite,and mylonitized granite were 173.7±1.4 Ma,173.34±0.45 Ma,and 178.1±0.64 Ma,respectively,representing their age at the early stage of the Yanshanian,rather than the predecessors.Think of the Hercynian period.The salinity of the ore-forming fluid in the bright gold deposit is 5.40~12.19%NaCl.eqv,the density is 0.67~0.97g/cm3,the homogenization temperature of mineralization is 200?-280?,and the ore-forming pressure is 40~76MPa.It is 5.01~7.09 km.The analysis indicates that the type of genetic origin of the Xianguang gold deposit is a medium temperature hydrothermal vein type gold deposit.It was determined that the genetic type of the Heping deposit is a deposit-metamorphic iron deposit.By analyzing the regional Bugay gravity and aeromagnetic data,it was found that the study area is bounded by the first line of Caoxian-Shancheng Township.The geophysical characteristics of the North West and South East regions are significantly different.The deep faults of the Huifa River serve as the hub.Different geophysical fields and different geological structures are formed on the sides.The upper limit of the Bug gravity value in the southeast region is slightly higher than the upper limit of the northwest region;the positive and negative magnetic field distribution in the northwest region is mainly characterized by the east-west direction and the local negative magnetic field.The direction is north-west.All the areas in the South East are distributed in the northeast direction,and the positive magnetic field and the weak positive magnetic field dominate in the positive magnetic field.According to geochemical data,the general trend of the spatial distribution of the geochemical field in the study area is that the small high-value areas are banded or discontinuously beaded surrounded by a large area of background area or semi-enveloped,with gold and silver in the area.Iron enrichment is in good condition.Based on the comprehensive information of geological,geophysical prospecting,geochemical exploration,and minerals in the Hengdaohe area,it is believed that this area is a favorable area for finding Au,Ag,and iron,and a total of three AuI-level(A-grade)metallogenic prediction areas have been delineated.They are: Au I(A level)prospecting target in Xianguang District,Au I level(A level)prospecting target in the Liangshan District,and Au I level(A level)prospecting target in Huangying village of Heping District.