The Laguna Verde ignimbrite was erupted 4-3 mya ago and is associated with these two calderas. Other dates are 4.5 ± 0.5 to 3.0 ± 0.2 mya. The ignimbrite covers an area of , cropping out southwest of the Laguna Amarga ignimbrite. The Laguna Verde ignimbrite ranges from dacite to rhyolite in composition, containing biotite, pumice, quartz and sanidine.