Cordon de Puntas Negras

Geography & Climate

Cordon de Puntas Negras is located in Chile, within the Central Andean Volcanic Arc of the broader South America Volcanic Regions. Situated at 23.74° S, 67.53° W in the Southern Hemisphere, the volcano lies within a subtropical climate zone. At 5,852 meters above sea level, Cordon de Puntas Negras reaches well into the permanent snow and ice zone. Glaciers and snowpack on the upper slopes create the potential for lahars — destructive volcanic mudflows — during eruptions, as heat rapidly melts ice and snow. The volcanic landform is characterized as a composite, which describes the physical shape and structure of the volcanic edifice as observed from the surface.

Geological Context

Cordon de Puntas Negras sits in a subduction zone, where one tectonic plate dives beneath another, creating intense heat and pressure that generates magma. Subduction zones are responsible for many of the world's most explosive volcanoes and deadliest eruptions. For communities in Chile near Cordon de Puntas Negras, this tectonic setting means the volcano is capable of producing powerful explosive eruptions, pyroclastic flows, and lahars that can threaten populated areas within tens of kilometers of the summit. The dominant rock type is andesite / basaltic andesite, a dark, fine-grained volcanic rock that forms from rapidly cooling, low-viscosity lava. Basaltic eruptions tend to be less explosive and produce fluid lava flows that can travel long distances. While less immediately dangerous than explosive eruptions, basaltic lava flows can destroy structures and infrastructure in their path, and volcanic gases released during these eruptions can affect air quality over a wide area.

GVP Reference Summary

Two intersecting volcanic chains, the Cordón de Puntas Negras and Cordón Chalviri, trend roughly SE from Chiliques volcano to Volcán Puntas Negras stratovolcano and SW from there to Cerro Tuyajto, respectively. The chain of small cones, lava domes, lava flows, and maars covers an area of about 500 km2 and contains at least 25 different vents. The Cordón de Puntas Negras is situated along the southern margin of the 35 x 70 km Pliocene La Pacana caldera. The pristine morphology of many of the volcanic features indicates a Holocene (de Silva and Francis, 1991) or historical (González-Ferrán, 1995) age. Small cones such as Cerros Cenizas, Aguas Calientes, Laguna Escondida, and Chinchilla have well-preserved summit craters and produced short lava flows. A distinct maar-type vent is present, as well as a 13 km2 silicic lava flow and dome complex. A volcanic center immediately SE of Cerro Laguna Escondida appears to be the youngest vent of the complex.

— Smithsonian Institution, Global Volcanism Program