Abstract:

The giant metallogenic belt around the Middle and Upper Yangtze Block is a product of multicycle and multistage regional tectonic evolution. The major metallogenic systems include the sedimentary-hydrothermal sedimentary metallogenic systems, epigenetic basin fluid metallogenic system, and magmatic hydrothermal metallogenic system. The Nanhua Mn, Sinian Pb-Zn, Sinian-Cambrian Ag-V-polymetallic, and Permian Mn sedimentary-hydrothermal sedimentary metallogenic systems were mainly formed at the margin of the paleocontinent during the tectonic transition from compression to extension. The development of large and super-large deposits were constrained by the tectonic network system at the continental margin. The favorable environment for mineralization is the aulacogen controlled by extensional faults. The continuous supply of ore-forming fluids from the syngenetic fault system was the key factor for ore genesis. Indosinian to early Yanshanian epigenetic basin fluid Pb-Zn metallogenic system is the dominant metallogenic system in this region. It developed in the combination zone of the basin and orogenic belt. The development of large and ultra-large deposits was mainly controlled by the combination of faults, strata, and lithology. The Yanshanian magmatic hydrothermal Pb-Zn-polymetallic metallogenic system was controlled by the intrusive contact structures, while Pb-Zn orebodies mainly developed in the outer zone. The Yanshanian magmatic hydrothermal Au-polymetallic metallogenic system also developed in the combination zone of the basin and orogenic belt. The large and ultra-large deposits were controlled by the combination of faults, folds, and concealed granites. Finally, the preliminary metallogenic lineages of major metal deposits around the Middle and Upper Yangtze Block were constructed.

Key words: Pb-Zn-polymetallic metallogenic system, Mn metallogenic system, Au-polymetallic metallogenic system, metallogenic lineage, Middle and Upper Yangtze Block