Eruptive activity at Mentolat has been ongoing since the Pleistocene, several 35,600 and 34,200 years old tephra layers in Laguna Potrok Aike may be linked to Mentolat and other explosive eruptions took place over 17,340 years ago. An eruption during the late Glacial formed the MENo tephra and another eruption 11,700 years ago produced about of tephra. The volcanic activity has been inferred from tephra layers in lakes and outcrops, about 13 eruptions have been identified with the help of tephrochronology.