Abstract:

Mineralizing processes of gold deposits were controlled by the strong and widespread magmatic activities in the middle part of Bangonghu-Nujiang matallogenic belt. The internal relations of magmatic activities, mineralizing processes and earth dynamics have been studied on the base of study of spatial distribution and evolution of magmatic activities. A unified and periodic dynamic model which included six periods has been proposed. The first period is the embryonic period of Qiangtang terrane and Gangdisi terrane in the early and middle Triassic. The second is the embryonic period of Bangonghu-Nujiang ocean basin and Yaluzangbujiang ocean basin between late Triassic and early Jurassic. The third is between the late part of early Jurassic and the middle Jurassic when the ocean basin extended and ophiolite suite and its relational gold deposits had been formed. The fourth is between the middle part of late Jurassic and early Cretaceous when the ocean basin closured, the terranes matched, Yaluzangbujiang ocean basin subducted to the north and the metamorphic hydrothermal solution and the Au (Cu)-Sn-Pb-Zn mineralization series related to granite had been formed. The fifth is between the middle Cretaceous and late Palaeogene when Yaluzangbujiang ophiolite emplaced. The last period is between late Palaeogene and now when mantle plume formed, plateau uplifted and gold placer formed.

Key words: metallogenic model, gold deposits, earth dynamics, Tibet