Permian age of the Wudaogou Group in eastern Yanbian: detrital zircon U–Pb constraints on the closure of the Palaeo-Asian Ocean in Northeast China

Detrital zircons yield U–Pb ages ranging from 253 ± 5 to 818 ± 5 Ma, and indicate that the provenance of the Wudaogou Group experienced four tectonic–thermal events between 818 and 253 Ma: Neoproterozoic (ca. 818–580 Ma), Cambro–Ordovician (ca. 500–489 Ma), Devonian–Carboniferous (ca. 422–300 Ma), and middle–late Permian (ca. 269–253 Ma). The youngest detrital zircon, with a U–Pb age of 253 ± 5 Ma, defines the maximum depositional age of the Wudaogou Group.

The presence of the Cambro-Ordovician and Neoproterozoic detrital zircons implies that the source of the Wudaogou Group had an affinity with Northeast China, which leads us to conclude that the Solonker–Xra Moron River–Changchun Suture extends from Wangqing to Hunchun in eastern Yanbian, and that the Palaeo-Asian Ocean may have closed at the end of the Permian or Early Triassic period.