Tupungatito volcano, the northernmost historically active volcano of the central Chilean Andes, is located along the Chile-Argentina border about 90 km east of Santiago and immediately SW of the Pleistocene Tupungato volcano.  Tupungatito consists of a group of 12 Holocene andesitic and basaltic andesite craters and a pyroclastic cone at the NW end of the 4-km-wide, Pleistocene dacitic Nevado Sin Nombre caldera, which is filled by glaciers at its southern end and is breached to the NW.  Lava flows from the northernmost vent have traveled down the NW flank breach.  Tupungatito has produced frequent mild explosive eruptions during the 19th and 20th centuries.