Caldera del Atuel

The 30 x 45 km Caldera del Atuel complex, ~30 km NW-SE and 45 km NE-SW, lies just east of the Argentina-Chile border and 18 km SSW of the rim of the Pleistocene Diamante caldera. The western rim in part follows the international border, and the headwaters of the Río del Atuel drain to the SE through a wide breach in the caldera rim. The broad floor of the caldera contains with 15 dacitic lava domes and 25 basaltic andesite to andesitic stratovolcanoes and cinder cones. A group of cones known as Las Lágrimas overlies the SW rim of the caldera, and Volcán Guanaqueros on the NE flank of the caldera is a group of young basaltic-to-andesitic cinder cones. The Volcán Overo complex in the E-central part of the caldera and the Volcán Sosneado complex in the S part of the caldera contain numerous very youthful basaltic-to-andesitic pyroclastic cones and lava flows. The Overo complex contains 20 centers, and lava flows of the Sosneado complex cover an area of 200 km2.