Decoupling of metamorphic zircon U-Pb ages and P-T paths in the Dunhuang metamorphic complex, northwestern China

•Metamorphic zircon ages and REE data indicate 1.9–1.8 Ga metamorphism.•Garnet, titanite and apatite ages indicate thermal overprinting during 345–236 Ma.•Decoupling of metamorphic zircon U-Pb ages and P-T paths due to thermal overprinting.•The Dunhuang area was like a long-lived hot continental arc during the Paleozoic.