Geological Characteristics And Metallogenic Conditions Of Spodumene Deposit In Guanyinqiao,Jinchuan County,Sichuan Province

Guanyinqiao spodumene deposit is a medium-sized spodumene deposit located in the north of Western Sichuan Plateau.It belongs to Jinchuan County,Aba Tibetan Autonomous Prefecture.It belongs to Dadu River system,with deep terrain cutting,large height difference and deep mountains and valleys.It is a typical rare metal granite pegmatite deposit.The geotectonics is located in the central part of Songpan Ganzi orogenic belt,with less strata exposed in the area and Mesozoic strata developed.The research level of the mining area is relatively low,and the theoretical research on the geological characteristics and metallogenic conditions of the deposit is less,which leads to certain restrictions on the development of prospecting and exploration work.In this paper,based on the field work of Guanyinqiao spodumene deposit in Jinchuan County,Sichuan Province,and the collection of relevant documents,through the analysis and summary of the research results of pegmatite type rare metal ore,the geological characteristics of the strata,surrounding rock,structure,ore body,magmatic rock and other deposits in the mining area are studied;combined with the detailed identification of the light sheet and thin section and the analysis of the geochemistry,the ore is identified The main components and structural characteristics of the ore-forming geological conditions are analyzed.The Kerin mica monzogranite is a rock mass closely related to rare metal mineralization.Around the rock mass,there are concentrated areas in the north,West,East,South and Southeast.The deposit is located in the Western intensive area.The ore-forming fluid is mainly derived from the crystallization differentiation of granitic magma.When the crystallization comes to an end,the residual magma of rare metal elements such as Li,Ta,Nb,Sn is formed,and a large amount of them are concentrated in the favorable position of the structure to form pegmatite deposit.The regional structure and its secondary structure provide a place for the migration and precipitation of ore-forming materials,and also control the ore-bearing pegmatite The distribution,morphology,occurrence,scale and so on.The Guanyinqiao spodumene deposit is located in the middle of Songpan Ganzi orogenic belt and on the edge of the central fold nappe belt of the markang passive continental margin.The ore bearing parent rock is the Korin mica monzogranite;the keyin complex anticline,Guanyin inverted syncline,waerdu fault,etc Guanyinqiao fault,secondary faults,joints and other structures play an important role in controlling the Guanyinqiao spodumene deposit.The upper member of Zagunao formation?T₂z¹?and Upper Triassic jiwo formation?T₃zh?of the Triassic Xikang Group are the ore hosting strata,which not only provide ore-forming materials for the deposit,but also have good sealing conditions,which are conducive to the formation of the deposit.According to the analysis of fluid inclusions,Guanyinqiao spodumene deposit is of great significance The temperature of ore-forming fluid inclusions is 250-290?,and the salinity is 0.2-15.1 wt%The results show that the ore-forming fluid of Guanyinqiao spodumene deposit has the characteristics of medium temperature,low salinity and low density,which is closely related to the hydrothermal metasomatism of pegmatite magma,and is in the late stage of the whole pegmatite formation in terms of physical and chemical environment.Based on the comparison of typical deposits and the geological experience prospecting model established according to the metallogenic geological background,geological characteristics of the deposit and prospecting indicators,through the comparison of the sufficiency and necessity of each attribute in the model,these measures should be changed into the corresponding scores defining the main indicators in different models,and it can be concluded that Guanyinqiao spodumene mine area has medium prospecting potential.