Genetic type, mineralization epoch and geodynamical setting of endogenous copper deposits in the Great Xing''an Range
大兴安岭地区内生铜矿床的成因类型、成矿时代与成矿动力学背景

The Great Xing'an Range, located in the eastern Mongolia-Hinggan orogenic belt, is characterized by intense tectonic and magma activity, abundant endogenous non-ferrous and precious metal mineral resources. Based on studies of geological characters, genetic type and chronology, the endogenous copper deposits can be divided into three genetic types: porphyry copper deposits, epithermal high-sulphidation deposits (Cu-Ag, Cn-Sn) and contact-metasomatic deposits. The mineralization is collectively closely related to high-K calc-alkaline I-type granitic magmas, except for Cu-Sn deposits. In the eastern part of the area, porphyry copper deposits were mostly emplaced during 180~170Ma, with a small amount in around 485Ma, whereas epithermal high-sulphidation copper-silver deposits, in the middle of the Great Xing'an Range, have an emplacement age of 170~160Ma. In the west, epithermal high-sulphidation Cu-Sn deposits which emplaced between 150Ma and 135Ma are related to A-type granitic magma. The contact-metasomatic deposits are associated with above two types, concentrated in 180~160Ma and 150~135Ma. Conclusions can be drawn that the metallogenic geodynamic setting is consistent with Early Paleozoic collision between the Xing'an block and Songnen block, Middle Jurassic collision between the Siberia and North China plates epicontinental accretional belt, and the crustal extension and thinning effects of Early Cretaceous collisional orogeny. Accordingly, these deposits emplaced in intra-continental transformation orogenic regime or post-orogenic extension stages. This result will provide a scientific basis for in-depth study of the endogenous polymetallic mineralization regularity.