Thrust Nappe Structure Tectonics In Yongping-Shitan G Area, And Analysis Of Ore-controlling Structure Of The Longtougang Deposit, North Eastern Jiangxi

Yongping-Shitang nappe structure and Longtougang mine are located in the Nort h wuyishan metallogenic belt, which is in the northwest of Cathaysian plate. Since the middle Jurassic, because of large plate movement of the East Asia lithosphere, strong tectonic deformation and magmatism were happened in this metallogenic belt. Based on the field geological investigation, and the systematic collection and sorting of previ ous studies, our paper is researching on the metallogenic geological background and t he geological characteristics of the deposit, summarizing the the structural ore-control ling rules and the origin of deposit. We have achieved some achievements and conclus ions, as follows:.1.Because of the Izanagi subducted to the eurasian plate in the yansh anian, the Yongping-Shitang nappe structure is formed. And it is controlled by the mid dle Jurassic nappe which is composed of the layers that are from Hutuo System of the mid-proterozoic era to upper Sinian System of the Neoproterozoi era, it has pushing to the top of Shuibei group of the lower Jurassic syetem. The napping direction is SE-N W, and the napping time is 175-150Ma. The exotic rock series are highly deformed, a nd the native rock series are highly fold developed.2.The Longtougang mine is locate d in the Yongping-Shitang nappe structure, the ore are controlled by the interlayer-glid ing structures in the reversed fold, which is formed by the nappe structure in the meso zoic era. The hydrotherm filled the F2 and F4 fracture, which is formed by the NW-tre nding conjugated shear. The latter F3 fracture and the nappe structure have reform acti on to the ore body.3.The magmatic rocks developed in Longtougang mine are mainly granite porphyry, monzonitic granite porphyry and biotite monzonitic granite porphyr y. The zircon of monzonitic granite porphyry LA-ICP-MS U-Pb date suggest that it w as generated in the late Jurassic(153.9±1.4 Ma); the zircon of biotite monzonitic granit e porphyry LA-ICP-MS U-Pb date suggest that it was generated in the early Cretaceo us (151.3±1.4 Ma).4.According to the tectonic deformation and deposit characteristic s of the Longtougang mine, throughing the analysis of the tectonic background and th e mineralogenetic epoch of the typical deposit, we think that the place where nappe str ucture developed, C2o contained in overlying strata and the granite rock exsited may has relationships with the copper and molybdenum mineralization. As a result, the Lo ngtougang mine might have better prospecting for porphyry deposit.As a result, the L ongtougang mine is a shallow skarn - deep porphyry type deposit, which is controlled by the Middle Jurassic (170-150 Ma) nappe structure and the magma invasion activiti...