Characteristics Of Ore-controlling Structure And Metallogenic Model Of Typical Tungsten Deposits In Western Zhen'an, In South Qinling

The western tungsten deposit area of Zhen'an is located in the southern Qinling tectonic belt of the central compound orogenic belt of the Qinling Mountains.It is the southern-Qinling orogenic belt of the southern Qinling orogenic belt and the south-north-continental intracontinental orogenic belt.-The structural joint of the Hanyin Niushan-Xiaoerling northeastward tectonic magma belt.The western tungsten-molybdenum-gold multi-metal metallogenic belt in Zhen'an is a new area obtained by the new discovery and exploration evaluation funded by the Shaanxi Provincial Geological Prospecting Fund Project in recent years.The ore-forming geological conditions are superior.In recent years,with the continuous deepening investigation and analysis of local surveying units and mining companies,a number of large and medium-sized tungsten ore and tungsten molybdenum mines such as Jinpen,Dongyang,Qipangou,Yanggou,Guilinou,Yueheping and Walnut have been discovered.,molybdenum gold mine.However,the predecessors did not integrate enough the results of prospecting and exploration in this area,lacking overall and systematic evaluation studies,especially the tungsten-molybdenum gold ore-forming age,geological background,ore-controlling structure,and intrusive rock mass related to mineralization.There are few studies on the mining model,which restricts the deepening research of tungsten-molybdenum ore and further prospecting prediction work to some extent.Therefore,according to the existing characteristics of tungsten-molybdenum ore and its relationship with magmatic rock mineralization,the research on the ore-control structure of tungsten-molybdenum ore in this area is particularly important in the existing exploration and evaluation stage,which can not only be used for prospecting exploration in the study area.It provides scientific basis and also provides important data for the study of tectonic-magmatic-mineralization evolution of the South Qinling metalogenic belt.In this paper,the field investigation and indoor research of typical tungsten deposits such as Qipangou and Walnut Ping in the mining area are carried out,and the characteristics of the deposit,metallogenic regularity,ore-controlling tectonic style,prospecting prediction mark are summarized,and the area is proposed based on the previous research results.A new understanding of ore-controlling structures,summarizing and summarizing the ore-forming rules of this area,and establishing the metallogenic model of tungsten-molybdenum ore in this area,and obtaining the following understanding:(1)The ore-controlling structure in the ore-concentrating area is a tectonic fracture in two different directions from the east-west and the north-north-north-east direction.(2)According to the tectonic background of the area,the tectonic fractures in the northeast-north-northeast of the ore-concentrating area are formed by the Late Indosinian-Yanshanian tectonic activities,and the near-East tectonic fractures are mainly formed by the Indosinian tectonic activities.Compared with the Yanshanian tungsten-molybdenum ore-forming period,the near-East-West fault is a pre-mineral structure,while the NE-North-Northeast fault fracture belongs to the metalogenic structure.(3)The type of tungsten mineralization in the ore-concentrating area is mainly composed of hydrothermal quartz vein type and fault-controlled skarn type.The quartz vein type is mainly controlled by the northeast-north-north fault and joint fissures,and a small amount is near.The east-west fault control;the off-control skarn type is mainly controlled by the near-east-west fault fracture zone.(4)Through the study and analysis of the fluid inclusions in the tungsten-bearing quartz veins in the Qipangou tungsten deposit area and the Dongyang tungsten deposit area of the ore-concentrating area,it is considered that the ore-forming hydrothermal fluid rises along the north-north-eastern tectonic fracture to form the quartz vein scheelite,which is in the migration.During the process,the temperature is continuously reduced,and then the near-east-west structural fracture is poured into the skarn-type scheelite.(5)The re-Os dating of molybdenite in the typical deposits in the area shows that the metallogenic age is 196.3±3.3Ma~199.7±3.9Ma,which belongs to the Early Jurassic and the ore-forming period is the early Yanshanian.