Los Colorados (caldera)

[2] The caldera has a diameter of 30 kilometres (19 mi) and was formed 9.8 million years ago within a basement consisting of Paleozoic rocks, Miocene ignimbrites and older volcanoes.

[3] The caldera is the source of the 500 cubic kilometres (120 cu mi) Los Colorados ignimbrite,[3] which was erupted 7.9-7.76 million years ago.

[1] This ignimbrite is formed by highly welded dacite, is rich in pumice and has a dark pink colour.

Lava flows from Cerro Bayo and Cordón del Azufre have invaded the northwestern sector of the caldera.

[3] The Los Colorados caldera coalesces with the Lazufre structure along the Archibarca lineament and is associated with a major fault, the Pedernales-Arizaro overthrust.