Among the structures in the volcanic field, the Domo del Maule lava dome is of rhyolitic composition and generated a lava flow to the north that dammed the Laguna del Maule. This lava flow is joined by other lava flows from the , a small cone in the southwestern sector of the volcanic field; the lavas of this cone however are andesitic and basaltic. is a large lava flow of acidic rocks that is long in the northern sector of the volcanic field, close to the outlet of Laguna del Maule. It consists of two lobes with a volume of about and contains obsidian and vitrophyre. Crystals within the flow reflect the sunlight. The well-preserved lava flow is in the extreme southwestern sector of the volcanic field and originates at a tuff cone. This lava flow is thick, varying from to in length, and is about wide. The Barrancas centre has a volume of and reaches an elevation of .