Research On The Metallogenic Geological Characteristics And Prospecting Prediction Of The Daqiao Gold Deposit,West Qinling Orogen,Gansu Province

Current research shows that the Qinling orogenic belt is one of the most important metal metallogenic belts in China.The Daqiao gold deposit is located on the eastern edge of the West Qinling Mountains.Due to geochemical anomalies,it had remained unknown until recent years.It is a super large gold deposit.This article,starting with the geological and geochemical characteristics of the deposit,discuses the types of metallogenesis,metallogenic elements and the characteristics of the predicted elements of Daqiao Gold Deposit by using the technical analysis of ore field structure,rock and ore characteristics,wall rock erosion variation.The metallogenic process of the Daqiao Gold Deposit is roughly made up of four stages including sedimentary period,metamorphic period,hydrothermal period and supergene mineralization period.Among them,the hydrothermal period plays a fundamentally critical role in mineralization.The metallogenic geological body,metallogenic texture,metallogenic structural plane and characteristics are further confirmed by the evidences gained through studying the geochemical characteristics of the deposit.The studies concentrating on major and trace elements of the ore show that the silicified rock of Daqiao Gold Mine is very different from the sedimentary siliceous one which was previously thought containing higher Al/(Al+Fe+Mn)value and lower U/Th value.Sulfur isotope studies have shown that the sulfur in Daqiao Gold Mine is mainly derived from the strata,mainly consisting of sedimentary sulfur sources and mixed sulfur sources.Affected by sedimentation and magmatism,the variation range of the composition characteristics of lead isotopes is relatively small.The main lead isotopic composition of Daqiao Gold Mine falls within the range of the orogenic belt,and some falls within the upper crust.As far as the metallogenesis of Daqiao Gold Mine is closely related to magmatic activities,it is speculated that the magmatic hydrothermal activities provide the main ore-forming materials for the Daqiao Gold Deposit while stratum only makes a small contribution.This paper believes that the Daqiao gold deposit should be an orogenic gold deposit formed in the Late Triassic and it is closely related to the collisional orogenic process.In view of the fact that the Daqiao gold ore body is strictly controlled by the lithological interface between the Triassic flysch and the Carboniferous limestone in this area,the deposit may have a close relationship with the mineralization of the "silica calcium surface".Based on the above-mentioned,a spatial geological model named ?Trinity? Prospecting Prediction can be established which takes the form of dualistic structure consisting of the upper and lower levels of Daqiao Gold Mine.