Gold Deposits in the Eastern Tian Shan, Northwestern China

Abstract

The Tian Shan orogen extends for ∼2500 km in an E-W direction and is part of a complex system of orogenic belts of Phanerozoic age in Central Asia. In northwestern China, the Tian Shan is situated between two major crustal blocks–the Tarim in the south and the Junggar in the north. The orogen was formed by collision of island arcs with the Tarim and Junggar plates during Permo-Carboniferous time. Numerous syn-late to post-orogenic granitoids intrude the Tian Shan orogen, some of which may be linked to mineralization. Three gold deposits in the eastern Tian Shan–Kanggurtag, Xitan, and Jinouzhi–exhibit different styles of mineralization. Kanggurtag is an epithermal vein subsequently modified during deformation and metamorphism. Xitan is a volcanic-hosted high-sulfidation epithermal deposit, whereas Jinouzhi is a granite-hosted hydrothermal auriferous vein rich in sulfides. It is speculated that Kanggurtag was formed during island-arc magmatic activity, whereas Xitan and Jinouzhi may be related to post-orogenic magmatism, probably in an extensional setting.