thumb|Marmolejo top seen from the north. The face of the cliff shows altered rocks from the core of the volcano.
Volcán Marmolejo is a high Pleistocene stratovolcano in the Andes on the border between Argentina and Chile. It is located NNE of the active San José volcano, and is the southernmost -plus peak in the world. The Argentine portion is within the Argentinean protection area of Provincial Reserve for Multiple Use and Natural Recreation Manzano / Portillo de Piuquenes. It is on the border of two provinces: Argentinean province of Mendoza and Chilean province of Cordillera. Its slopes are within the administrative boundaries of the two cities: Argentinean city of Tunuyán and the Chilean commune of San José de Maipo.
Elevation
It has an official height of 6108 meters. Other data from available digital elevation models: SRTM yields 6097 metres, ASTER 6103 metres, ALOS 6085 metres and TanDEM-X 6129 metres. The height of the nearest key col is 4005 meters, leading to a topographic prominence of 2103 meters. Marmolejo is considered a Mountain Range according to the Dominance System and its dominance is 34.43%. Its parent peak is Tupungato and the Topographic isolation is 42.9 kilometers.