The area of Laguna del Maule was glaciated during the last ice age, with a glacial maximum occurring between 25,600 ± 1,200 and 23,300 ± 600 years ago. During this time a -wide ice cap covered the volcano and the surrounding valleys. Probably due to changes in the position of the Westerlies, after c. 23,000years ago the glaciers retreated above Laguna del Maule. The glaciation has left moraines and terraces in the area, with undulating hills lying close to the outlet of the lake. Poorly developed moraines with the appearance of tiny hills lie downstream of Laguna del Maule, and form small hills around the lake rising about above the lake level. Other climate changes in the Holocene such as the Little Ice Age are recorded from sediments in Laguna del Maule, such as a humid period in the 15th to 19th centuries.