Middle Triassic trachytic lava flows associated with coeval dyke swarm in the North Patagonian Massif: A postorogenic magmatism related to extensional collapse of the Gondwanide orogen

•Triassic igneous rocks from NE Patagonia were included in Monasa Formation.•The mesosilicic lavas are similar to a Triassic dyke swarm.•The trachytic lava flows cover an erosive surface carved over Permian granites.•The trachytic lava flows might be related to a postorogenic extensional process.•This Triassic magmatism is widespread in the North Patagonian Massif.

Graphical abstract