Antuco

Antuco volcano, constructed NE of the Pleistocene Sierra Velluda stratovolcano, rises dramatically above the SW shore of Laguna de la Laja. It has a complicated history beginning with construction of the basaltic-to-andesitic Sierra Velluda and Cerro Condor stratovolcanoes of Pliocene-Pleistocene age. Construction of the Antuco I volcano was followed by edifice failure at the beginning of the Holocene that produced a large debris avalanche which traveled down the Río Laja to the west and left a large 5-km-wide caldera breached to the west. The steep-sided modern basaltic-to-andesitic cone has grown 1,000 m since then; flank fissures and cones have also been active. Moderate explosive eruptions were recorded in the 18th and 19th centuries from both summit and flank vents, and lava flows have traveled into the Río Laja drainage.