Modelling of geodynamic regimes of precious metal‐bearing porphyry deposits: Lazurnoe deposit (Sikhote–Alin Belt, Far East) case study

Abstract

The research site includes part of the East Asian region within areas of SouthEast Russia and the boundary part of NorthEast China. The region has abundant precious metal deposits: gold and platinum group elements. The spatial distribution of these deposits is controlled by details of crustal and mantle geodynamics including the presence of faults of different types and kinematics, active plume, as well as by the position of the region above a stagnant oceanic slab. Spatial analysis of position, geodynamics, and synchronous formation of the largest East Asian gold districts (e.g., Aldan, Baley, and Jiaodong) and platinum-bearing massifs provide insights to their connection with mantle plumes and permeable zones at stagnant slabmargins. The occurrence of ore deposits and mineralization of precious metals inside the slab area is related to disjunctive structures of lower crust and upper mantle, such that their resources are considerably lower. This article considers numerical modeling of permeable tectonic structures exposed into mantle upwelling along active continental margins inside the slab area. Small-scale structures of this type potentially hold twophase alkaline massifs, which control the positions of intra-slab ore deposits, like the Lazurnoe Au-Mo-Cu porphyry deposit, situated in the southern part of the Sikhote-Alin belt. The small sizes of similar massifs impede their discovery, emphasizing the importance of the proposed prospective model for precious metal-bearing porphyry deposits in Western Pacific mobile belts.