The Carrán-Los Venados volcano group includes a group of about 50 basaltic to basaltic-andesite scoria cones, maars, and a small stratovolcano that are broadly aligned along a 17-km-long ENE-WSW trend ESE of Lago Ranco. The volcano group occupies a low-lying area north of the more topographically prominent Cordón Caulle-Puyehue volcanic chain, and many of the vents are postglacial in age. The Mirador scoria cone and two maars, Riñinahue and Carrán, were formed during eruptions in the 20th century. These historical eruptions were concentrated where the regional Liquine-Ofqui fault zone intersects the alignment of volcanic vents.