Late Silurian to Early Devonian volcanics in the East Kunlun orogen, northern Tibetan Plateau: Record of postcollisional magmatism related to the evolution of the Proto-Tethys Ocean

•409−420 Ma bimodal volcanics occurring in the East Kunlun orogen.•These volcanics formed in a postcollisional extensional setting.•Mafic magma derived from the asthenospheric mantle.•EKOB evolved into a post-collisional collapse stage since Late Silurian.