Abstract:
Granitic porphyries hosting the Tsagaan Suvarga and Shuteen porphyry-type copper deposits in the South Gobi, Mongolia, were dated by using SHRIMP zircon U-Th-Pb technique. The dating results show that the Tsagaan Suvarga granodiorite and Shuteen granite were emplaced at 368±4Ma and 333±4Ma, respectively, suggesting that they formed in two different geological epochs. In combination with data available, the authors hold that there are two metallogenic zones of porphyry-type copper deposits with different ages in the South Gobi area of Mongolia: one is Late Devonian in age, which is represented by Oyu Tolgoi and Tsagaan Suvarga copper deposits, and the other is Late Carboniferous in age, with the Shuteen and Mandah deposits being typical ones. The geological settings of the two porphyry-type metallogenic zones are preliminarily discussed in the context of regional tectonic evolution.