A review of the geological characteristics and geodynamic setting of Late Paleozoic porphyry copper deposits in the Junggar region, Xinjiang Uygur Autonomous Region, Northwest China

In this review, we describe the geological characteristics of porphyry copper deposits in Junggar region, Xinjiang, and place these into their metallogenic–tectonic context. These porphyry copper deposits are mainly found in four metallogenic belts: (1) a Late Silurian to Early Devonian Cu–Mo metallogenic belt in the Qiongheba area; (2) the Late Devonian Kalaxiange’er Cu metallogenic belt; (3) the Early Carboniferous Xilekuduke–Suoerkuduke porphyry-skarn Cu–Mo metallogenic belt; and (4) the Late Carboniferous Baogutu porphyry Cu metallogenic belt. The ages of mineralization can be divided into three broad intervals: <427–409 Ma, 378–374 Ma and 327–310 Ma. Homogenization temperatures of fluid inclusions in the porphyry copper deposits range mainly from 300 to 180 °C. Salinity ranges from 0.5 to 21.7 wt.% NaCl equiv and 28.9 to 66.76 wt.% NaCl equiv. Ore-forming fluids in the Baogutu and Yunyingshan deposits in the Baogutu and Qiongheba belts, were mainly derived from magmatic fluids, whereas those in the Halasu, Yulekenhalasu and Xilekuduke deposits in the Kalaxiange’er and Xilekuduke–Suoerkuduke belts were mainly derived from magmatic fluids, with some contributions from meteoric water. Sulfur isotope compositions of some porphyry copper deposits cluster around 0‰, indicating that the sulfur was probably derived from mantle-related magmas. The ore-forming processes in all porphyry copper deposits are closely related to the emplacement of intermediate, intermediate-felsic and felsic porphyry intrusions. Porphyry copper deposits in Junggar region developed in a range of tectonic regimes including continental arc, ocean island arc and post collisional settings.