Pular & Pajonales
Structure and Evolution
Cerros Pular and Pajonales are two major centers which define a 12 km long, NE-SW trending volcanic ridge forming the southern and most recent part of the Cerros de Coransoque (Figure 32.1;32.2). Cerro Pular (6,233 m) is at the north (P), while the larger but slightly lower Cerro Pajonales (5,958 m) is at the south (Pa). Another center, also known as Cerro Pajonales (5,732 m), lies immediately to the west of the main ridge and appears to be a young satellite cone to the Pular-Pajonales system.
Although much of the upper third of the system is obscured by snow, the ridge shows evidence for a long volcanic history. Numerous extensive lava flows can be discerned low on the flanks of the ridge, and there are several identifiable craters (i.e C) along the crest of the ridge - at least three on each of Pular and Pajonales. A crater on the southern part of the Pular massif contains a small lake, Laguna Pajonales. Although relatively well preserved at lower elevations, most of the lavas from Pular-Pajonales are obviously glaciated in the upper levels. Much of the activity from this system is pre-Holocene.
Cerro Pajonales (5,732 m) appears to be a major satellite vent, and is probably the site of the most recent activity in the system. Its cone is dark, and probably composed of recent scoria and ash, and it is the source of an extensive lava flow field which extends up to 10 km northwestwards. In their lower reaches, these lavas are morphologically very well preserved, but in view of the highly arid conditions on the lower slopes, their appearance may be misleading.
Nearby miners reported a small explosion occuring at Pular on April 24, 1990, but this has been contradicted by other witnesses and its vent location is unknown (Smithsonian Global Volcanism Program). Lavas erupted from the satellite vent of Cerro Pajonales were probably the most recent erupted products.
Smithsonian Inst Bull Global Volcanism Network 6/1990 and 1/1991.