New constraints on the polychronous nature of the giant Muruntau gold deposit from wall-rock alteration and ore paragenetic studies

摘要

Muruntau in north-central Uzbekistan is one of the biggest gold deposits in the world with5200 t of contained Au. Detailed observations from thin-section petrography of ore samples from the super-giant deposit and quantitative XRD analyses of variably hydrothermally altered host-rocks are reported here. These new data are used to argue that the unique size and nature of the deposit is the result of a combination of distinct and potentially temporally separated ore-forming events that probably spanned at least 60 Ma. Consequently, describing Muruntau as an entirely orogenic, thermal-aureole, or intrusion-related type of deposit might not be valid, and caution should be used when using deposit-scale features of this enormous occurrence in the formulation of genetic or exploration models.