Lonquimay Volcano is a stratovolcano of late-Pleistocene to dominantly Holocene age, with the shape of a truncated cone.

[1] It is located in the La Araucanía Region of Chile, immediately SE of Tolhuaca volcano.

The Volcanic Explositivy Index was 3, indicating tropospheric injections and catastrophic damage.

The eruption was from a flank vent and involved mostly andesite lava, and had been preceded by increased seismicity for three weeks.

[2][4] Research that models the internal architecture of the volcano indicate that Lonquimay has reached its maximum height and that any large eruption of lava will likely occur from flank vents and not from the summit.