SPECIFIC FEATURES OF ORE FORMATION IN THE EPITHERMAL KUBAKA GOLD-SILVER DEPOSIT, NORTHEAST RUSSIA

Abstract

The epithermal Kubaka is a unique deposit with a prevalence of gold and quartz in ores. This deposit belongs to the category of large gold deposits (more than 100 t of Au and 100 t of Ag with average grades of 20.2 and 21.3 g/t, respectively). The vertical extent of gold mineralization is 200–250 m, and the average thickness of orebodies is 12 m. The Kubaka deposit is located in the southern part of the Omolon cratonic terrane. The rock massif is clearly divided into the Precambrian crystalline basement and the overlying sedimentary and volcanosedimentary sequences ranging in age from the Proterozoic to the Upper Jurassic. The massif also includes the Early Cretaceous orogenic cover. Within the Omolon cratonic terrane, the Omolon metallogenic zone is distinguished from the Okhotsk–Chukot volcanogenic belt by long-term and multistage evolution of Au–Ag mineralization.