Vicuña Pampa

About

Vicuña Pampa is a volcano in Argentina. It is part of the Central Volcanic Zone of the Andes and is located on the southeastern margin of the Puna plateau. It consists out of a 30 kilometres (19 mi) wide volcanic complex that is constructed by outwards-propagating lava flows. The centre of the complex is carved out by a 18 kilometres (11 mi) wide depression, which was originally interpreted as a caldera but appears to be erosional in origin. It is drained southward by the Rio Vicuña Pampa. The volcano was constructed in two phases. In the first phase about 12 million years ago, the main volcanic edifice was constructed out of lava flows and probably formed a steep cone. After this stage, a phase of erosion, probably aided by higher orographic precipitation carved the present-day central depression. The second stage took place within the central depression and consists of lava domes.

Adapted from Wikipedia (CC BY-SA). Photography via Wikimedia Commons.