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.