| The Qipangou Tungsten Mine is located at the intersection of the NE-trending volcanic belt and the east-west tectonic belt in the northern part of Shiquan,the eastern part of Shiquan,and the eastern part of the Ningshan-Nanshaling area,which is superimposed on the Sinian-slip belt in the southern Qinling orogenic belt and the Yanshanian intracontinental orogenic belt.The structural junction is a newly discovered large quartz vein type scheelite.There is less scientific research on ore-controlling structures,mineralization alterations,and evolution of ore-forming fluids in mining areas.On the basis of summarizing the results of previous studies on the mineralization of the western tungsten-molybdenum deposit in Zhen'an,this paper analyzes the ore-forming tectonic environment,favorable ore-forming tectonic and mineralization alteration types in the mining area,and analyzes the mining area on the basis of field research work.The relationship between ore-controlling structure-alteration-mineralization.Through indoor experiments,the ore-forming fluid characteristics,fluid source evolution and metallogenic age are analyzed.The characteristics of other tungsten deposits in the area were carefully analyzed and compared.The ore-forming rules of the mining area are summarized,and the metallogenic model is established.The specific understanding results of the genetic model of the deposit are as follows:1.The Qipangou tungsten ore is mainly hydrothermal quartz vein type scheelite and skarn type scheelite.Quartz vein type scheelite is produced in the contact part of crystalline limestone,black cloud calcite schist and quartz vein,and ore body is affected by mining area.NNE is controlled to the fault structure.Skarn-type scheelite is produced in deep skarnized marble and skarn.2.The faults and joint fissures in the Qipangou mining area are mainly near-north-north and north-north-east,and most of them are filled with calcite quartz veins.In the deep part of the mining area,skarn mineralized minerals such as tremolite,diopside,wollastonite,muscovite,biotite,phlogopite,etc.,skarn type tungsten deposit,ore-forming hydrothermal fluid and skarnization The deeper the mineral composition is,the stronger it is.The surrounding rock alteration of the vein is mainly skarn,diopside,tremolite,marble and marble.3.The temperature measurement results of the fluid inclusions of the quartz disk of the Chessougou tungsten deposit show that the fluid uniform temperature is between 284 and424°C,the peak value is between 360 and 389°C,and the fluid salinity is between 2.0%and13.7%?wt%NaCl equiv?,the peak value is between 5.1%and 8.9%?wt%NaCl equiv?.The fluid density ranges from 0.52 to 1.08 g/cm3and the peak value is between 0.65 and 0.7 g/cm3.The gas phase components of the fluid inclusions are mainly CO2,N2,CH4 and H2O,and the liquid phase components are mainly H2O,in which the fluid inclusions in the main mineralization period are rich in CO2.The ore-forming fluid belongs to high temperature?360389°C?,medium-low salinity(5.1%8.9%?wt%NaCl equiv?,medium and low density fluid system.4.Hydrogen and oxygen isotope experiments show that the hydrogen and oxygen isotopes of quartz vein samples containing tungsten ore in the Qipangou mining area fall in the magma water area.The sulfur isotope experiment of pyrite shows that the distribution of?34Sv-CTD?‰?value of pyrite is concentrated,and the comparison with sulfur in nature shows that the value of?34Sv-CTD?‰?mainly falls within the range of magma.It is similar to the sulfur isotope distribution area of the typical Shizhuyuan tungsten deposit and granite intrusive rock mass in South China.5.The analysis of the Re-Os dating of Qipangou molybdenum ore shows that the dating age of the Qipangou tungsten deposit is 199.7±3.9Ma,which is the result of the measurement of the molybdenite in the typical mining area such as Dongyang and Walnut Ping in this area.The age of ore-forming mineralization is 196.3±3.3Ma199.7±3.9Ma,belonging to the Early Jurassic,and the metallogenic age belongs to the early Yanshanian period.The granitoid magmatism corresponding to the intrusive magmatic activity age of the ore concentration area may be between 205 Ma and 200 Ma.Compared with the regional magmatic rock mass,it is inferred that the granitic intrusive rock mass corresponding to the intrusive magmatic activity corresponding to the tungsten-molybdenic metallogenic age can preliminarily determine the ore-forming hydrothermal fluid of the tungsten deposit and the magmatic rock such as the Sihaiping-Rouge dam.It is related to multiple intrusion activities of the body group. |
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