The formation of magma chambers and thus of large volcanic systems has apparently been influenced by tectonic changes.

[5] Tephras erupted during its formation have been found hundreds of kilometres from Laguna Amarga.

[6] The 630 km3 (150 cu mi) Laguna Verde ignimbrite was erupted 4-3 mya ago and is associated with these two calderas.

[7] The Laguna Verde ignimbrite ranges from dacite to rhyolite in composition, containing biotite, pumice, quartz and sanidine.

Another ignimbrite, Los Colorados, is located at the edge of the Amarga caldera but its eruptive centre is unknown.