The field is formed by cinder cones, while the isolated centre is formed by a fissure fed lava flow. The southernmost cone is also the largest with a diametre of and features a high secondary cone nested within its wide summit crater. The eruption fissures also generated lava flows; the cones formed afterwards over the fissures. On the northern end of the Puyuhuapi channel, the eruptions filled part of the channel and separated Lake Risopatrón from it; this activity may have been phreatomagmatic in nature. Two edifices have a volume of and respectively.