Petrogenesis and tectonic implications of Middle Triassic basalts and rhyolites in the northern Qiangtang Block, central Tibet

•Triassic rocks in northern Qiangtang Block include basalts-rhyolites (237–235 Ma).•Basalts were originated from metasomatized mantle sources.•Rhyolites were generated from newly formed basaltic lower crust.•The formation of studied suite was related to Paleo-Tethys oceanic slab subduction.