The relationship between thrust-fault and the syntectonic magmatism in Chuankeng-Tongshan, northeastern Jiangxi Province

This paper gives the conclusion that the copper deposit and the ore-forming rocks in Chuankeng-Tongshan area in Jiangxi Province were controlled by Mesozoic thrust-fault, by tectonic deformation analysis in the field. The thrust-fault’s surface undulate and overall dip towards SE. The exotic block composed of carbonate, shale and pelitic siltstone from middle Carboniferous to upper Triassic and the autochthon crop out Lower Jurassic. Deformations of exotic block shows isoclinal fold, associated with different scale of thrust fault and bedding detachment structure. Some recumbent and box folds are local existence. The thrust-fault moves from SE to NW. The ore-forming rocks intrusive to the thrust bedding detachment as mutual paralleled sheet. Other research in rock geochemistry and isotopic geochronology showed that the magma formed in magmatic arc under extensional environment, around 170 Ma. According to the stratigraphic age, the relationship of Mesozoic thrust-fault and the granite in Dexing area, the result inferred that the magma was syntectonic intrusion rocks, and controlled by the thrust-fault. And this probably results from the subduction of Pacific plate and southeast continental of China, and leads to the incrassation lithosphere and large scale nappe, then induces the lower earth crust remelting and magma invade.