Analysis of Orebody Morphology and Tectonic Genesis of the Siding Lead-Zinc Deposit of Guangxi

Studying the classification of orebody morphology and identifying the types of ore-forming structures controlling the orebody are the basic work for the research and prediction of ore-forming structures, and have guiding significance in the deep prospecting work of the mine. The Siding Lead-Zinc deposit in Guangxi is a typical representative of medium-large deposits in the Lead-Zinc metallogenic region in northern Guangxi. After many years of mining, the three-dimensional morphology of the orebody has been fully revealed, and it has good conditions for studying of the orebody morphology and structural genesis of the deposit.In this paper, based on the study of orebody morphology, the structural mineralization mode of orebody is constructed by analyzing the geometric characteristics and genesis characteristics of orebody morphology, and then the tectonic genesis of ore deposit formation is analyzed and discussed from the regional and field kinetic levels. The results show that: ① There are two types of ore-forming structures in the Siding mining area. One is the early tectonic fluid type ore-forming structure, which controls the vein Lead-Zinc orebody; The other is the late tectonic ore-forming structure, which controls the altered rock type lean orebody and superimposes on the early vein ore body. ② The orebody morphology is composed of three types of orebody morphology, namely, the structural bedding vein type formed by the control of the north-east right-trending tensional fault, the structural shear vein type formed by the control of the north-west right-trending tensional fault, and the structure-fluid type formed by the control of the brittle-ductile shear zone. Based on the orebody morphology, the structural bedding mineralization model represented by No. I and IV orebodies and the structural slicing mineralization model represented by No. V ore bodies are established. ③ The regional dynamics shows that the Siding mining area has experienced multiple tectonic movements, especially the two dynamic transformations in Indosinian period (the early SE regional compression pressure was converted to east-west rightward strike-slip shear, and the late near-EW rightward strike-slip shear was converted to east-west compression), which provided superior dynamic conditions for the formation of the deposit. ④ According to the ore field dynamics analysis, the Siding Lead-Zinc mineralization occurred in the brittle-ductile shear zone evolution to the brittle stage, and the stress weakening, deformation decomposition, progressive deformation, non-coaxial shear and interlayer Sliding jointly controlled the formation of various geometric orebody morphology.