Pular is a massive stratovolcano located in the Antofagasta Region of northern Chile, about 15 km west of the border with Argentina, which in this area is a straight line between the summits of Socompa volcano and Cerro del Rincón. Pular, along with Cerro Pajonales, forms a high volcanic ridge, which runs in a generally north-east to south-west direction for. Southward, following the same direction as the ridge, lies Socompa volcano. The ridge's crest forms a drainage divide between Salar de Atacama basin and Salar de Pular basin. This latter is a bowl-shaped basin enclosed on the east by Aracar volcano. In the Kunza language Pular means "The Eyebrow".
The Andes of northern Chile are formed by a number of volcanoes, some of which reach elevation. During winter they are covered with snow but the climate of the region is arid and the snow disappears during the summer months; only on some high summits like Ojos del Salado and Llullaillaco does ice exist. However, traces of past glaciation occur on other volcanoes. The Pajonales-Pular volcanic massif is formed by andesitic and dacitic rocks and covers an area of on faultedMiocene sediments. The massif consists of an alignment of volcanoes and two subunits, a heavily eroded unit that consists of Pajonales and Pular proper and a younger unit consisting of volcanic domes. These domes reach heights of and one of these overlies a glacial moraine. Rocks of the older unit are 3.9 million years old, while one of the domes has been dated to be 1.8 million years old. Numerous moraines occur within the drainage network of Pajonales-Pular. The mountain was extensively glaciated in the past, with five glacier systems on its northwestern and six on the southeastern slopes. The glaciers reached lengths of and formed moraines at less than elevation. A snowfield presently occupies one of the areas on the southeastern slopes that was formerly glaciated, and ephemeral lakes filled with snowmelt water occasionally appear on the mountain.
