Characteristics and genesis of digenites in southeast mining segment of Zijinshan Au−Cu Deposit

The Zijinshan Au−Cu Deposit is a well-preserved epithermal-porphyry Cu−Au polymetallic metallogenic system. Through detailed petrological and petrographic studies, the mineral assemblages and structural features of digenite in the southeast mining segment of the Zijinshan Au−Cu deposit were summarized. Based on their macro and micro characteristics, 3 types of digenite were identified: typeⅠdigenite with disseminated textures, type Ⅱ digenite with sulfide vein textures, and type Ⅲ digenite with alteration vein textures. In conjunction with previous data, the sequence of formation of the main metallic minerals in the southeast mining segment of the Zijinshan Au−Cu Deposit was established. Based on the combination of metallic sulfide minerals and their relationship with alteration, it is preliminarily concluded that all 3 types of digenite are primary digenites associated with hydrothermal action. Type Ⅰ digenite is related to the porphyry metallogenic system, while types Ⅱ and Ⅲ digenite are associated with epithermal metallogenic systems. The digenite in the southeast mining segment of the Zijinshan Au−Cu Deposit is a product of the transition zone from the porphyry metallogenic system to the epithermal metallogenic system.