 The last eruption may have generated a caldera that was later obliterated.Emission of lava flows occurred during the Toconquis phase as well, in general there was vigorous volcanic activity between the eruptions that formed the main ignimbrites.The Cueva Negra ignimbrite was emplaced after the Toconquis Group, and small lava domes and pyroclastic flows continued to be erupted until the Galán ignimbrite proper.