Gold mineralization in the Bangong Lake-Nujiang metallogenic zone, Xizang

The gold deposits have long been known as one of the dominant mineral resources in the Bangong Lake-Nujiang metallogenic zone in Xizang. In the present paper, the authors carry out a preliminary study of geological setting, genetic type, spatio-temporal distribution and mineralization of the gold deposits on the basis of previous results and field geological survey. The findings have disclosed that the gold deposits(spots)in the Bangong Lake-Nujiang metallogenic zone are E-W oriented, and occur mostly as paragenetic gold and associated gold, and scarcely as single gold. The above-mentioned gold deposits may be classified into four types:skarn-type, porphyry-type, orogeny-type and supergene low-temperature hydrothermal type. The mineralization ages may be traced back to the Late Jurassic to the Late Cretaceous. These gold deposits may be involved into two mineralization systems, including the magmatic-hydrothermal gold mineralization system associated with the oceanic crust subduction and the gold mineralization system associated with the continental collision and mountain-building. The former may be composed of three types of deposits:the supergene low-temperature hydrothermal type copper-gold deposit, porphyry-type copper-gold deposit and skarn-type gold-copper deposit, whereas the latter may be subdivided into three types as well:supergene low-temperature hydrothermal type copper-gold deposit, orogeny-type gold deposit and skarn-type gold-copper deposit.