Upper Crust Structure And Deep Metallogenic Background Of Jinding Ore Concentration Area In The Sanjiang Area Of Yunnan

Jinding Pb Zn deposit is located in the Mesozoic Cenozoic basin of Lanping-Simao block in Sanjiang area of Yunnan.Its reserves rank third in the world and second in China.Since the discovery of the deposit,a large number of scholars at home and abroad have not reached a final conclusion on the metallogenic mechanism of Jinding Pb Zn deposit.In this paper,the deep seismic sounding profiles in Sanjiang area of Yunnan are collected and sorted.After sampling and interpolation,the deep structural characteristics and the deep metallogenic background of Sanjiang area of Yunnan are obtained.Then,the deep seismic reflection profile of Jinding ore concentration area is refined to obtain high-quality upper crust structure;Combined with other geological and geophysical data,the metallogenic model of Jinding ore concentration area is obtained.The results are as follows:1.There is a low-velocity body in the middle and lower crust of Sanjiang area,with26°N as the boundary,and the development degree of this low-velocity body is different.2.The Jinding ore concentration area is located above the lithosphere thickness and crustal thickness gradient zone,and the low-velocity and high-conductivity zones are developed in the middle and lower crust,which indicates that the metallogenic process is related to deep action.3.Six thrust faults in the deep part of Lanping Basin are identified,which may be related to the two-stage compression.These faults constitute the migration channel of basin fluid and control the emplacement of Jinding super-large deposit.