A review of the geological characteristics and spatiotemporal distribution of copper–gold deposits in the Central Asian Orogenic Belt, Xinjiang, Northwest China

Abstract

Northern Xinjiang (Altay, Junggar, Tianshan, and Beishan) is an important part of the Central Asian Orogenic Belt (CAOB) and is characterized by multiple episodes and multitype mineralization in the Late Paleozoic. Cu and Au deposits predominantly occur in northern Xinjiang; however, the geological characteristics and spatiotemporal distribution of Cu–Au deposits remain unclear. The Cu–Au deposits are largely distributed in Altay, Junggar, and Tianshan, with minor deposits in Beishan. We recognize seven types of Cu–Au deposits in the Xinjiang Central Asian Orogenic Belt (XCAOB): volcanogenic, porphyry, iron oxide–copper–gold (IOCG), intrusion-related, epithermal, skarn, and orogenic. Of these types, volcanogenic and porphyry deposits are the most common. Ore formation in Cu–Au deposits can be divided into five mineralization episodes: Late Ordovician–Middle Silurian, Devonian, Early Carboniferous, Late Carboniferous–Early Permian, and Middle–Late Permian. Among these episodes, the Devonian and Carboniferous are the main mineralization episodes, during which porphyry, intrusion-related, IOCG, and volcanogenic deposits formed. The Cu–Au deposits in the XCAOB developed in diverse tectonic regimes, including island arc, continental arc, collision, and postcollisional extensional tectonic settings.