One of the most notable features of this volcano is its two kilometer wide caldera, that is 400 m (1,300 ft) in depth below the crater rim.

Along the western edge of the Ribeirinha Volcano, the Central Volcanic Complex formed about 410,000 years ago,[2] along with several structures that arose from tectonics.

Evidence of this process has not been preserved due to subsidence, but it is generally believed[3] that two formations (an Upper and Lower group) reflecting a geochemical variation that occurred about 16,000 years ago.

The Lower group (from 410,000 years ago), was marked by the predominance of a Hawaiian/Strombolian eruptive process, that was composed of basaltic and benmoreitic rocks.

The flanks of the stratovolcano also include the Morro de Castelo Branco and peninsula of denser material that have resisted erosion.