A Study On Deep Electrical Structure And Mineralization In Wuyi Metallogenic Zone Of Cathaysia Block

Wuyi metallogenic belt across Jiangxi and Fujian provinces,by a deep fault that Zhenghe and Dabu,south from Guangdong provincial boundary,north to railway of Shangrao to Qingjiang,east to the area of Sanming to Longyan,west to the area of Ningdu to Dingnan of Jiangxi provinces,connected to the southeast end of the Yangtze plate.Wuyi metallogenic belt are rich in metal and non-metallic mineral such as tungsten,tin,iron,lead,zinc,copper,gold,silver,uranium,porcelain clay and coal mine.Metallogeny of Wuyi metallogenic belt was researched by Chinese and foreign scholars,but most of the researches were confined to the earth's crust surface.It is necessary to study its deep structure and dynamic characteristics of tectonic movement from the deep,especially from the upper mantle and asthenosphere.People can went up from the macro to research the deep tectonic movement of Wuyi metallogenic belt,to learn the mineralization process of the metallogenic belt,as to provide theoretical basis for further ore-prospecting work deployment and specify the exact direction.Paper according to the 7 magnetotelluric sounding profiles with 264 sounding point data of middle-northwest Fujian,southeast Jiangxi and Zhejiang in the south,to run the MT two-dimensional nonlinear conjugate gradient inversion by TM inverse model,and then obtained two-dimensional electrical structure model.To analyze the electrical characteristics of the main tectonic units of Wuyi metallogenic belt,found that Wuyi uplift belt transverse electrical characteristics are obviously different,longitudinal shows the characteristic of high impedance in surface is obvious.That's the reflection of the granite and igneous rock distribution area.The tenuation of crust of Wuyi metallogenic belt in deep is obvious.The thickness of Wuyi metallogenic belt is thinner than both sides of the crust thickness.The low-resistance of fault zone extends to supremacy mantle,the author guess that is the reflection of deep asthenosphere upwelling and the upper mantle substances transporting to the earth's crust through deep fault.According to the analysis of the metal ore deposit distribution in Wuyi metallogenic belt and geological characteristics and metallogenic tectonic setting of the main large metal ore deposit in Wuyi metallogenic belt,extrapolate that Yanshan period is one of the important metallogenic epoches in Wuyi metallogenic belt.The tectonic activities during the period was intense,leading to the further development of north east,north-north east fault zone,nappe tectonics and ductile shear zone.With the collision of plates extruding from the Pacific plate,the deep material balance system of asthenosphere was destroyed,then deep convection disturbance of asthenosphere made the asthenosphere upwelling.Then Huaxia plot came to the stage of lithospheric stretching thinning.Mantle material along the deep fault belt transported constantly to the earth's crust and provided a large amount of heat energy.Its driving effect prompted useful minerals in crust-mantle to be extracted and transported.Along with the deep convection disturbance leveled off,the ore-forming elements in the structure of the particular site were gathered and stored when prompted by a variety of factors such as tectonic stress extrusion and magmatic contact metasomatism.Thus forming the deposit.