GASPAR, J.L., FERREIRA, T., QUEIROZ, G., WALLENSTEIN, N., PACHECO, J., GUEST, J., DUNCAN, A., COLE, P.(1995)-Evolução Morfoestrutural do vulcão das Furnas (ilha de S.Miguel, Açores). Museu e laboratório mineralógico e geológico - Memória nº4. p.999-1003/1995. ISSN 0871-1607​

Furnas volcano lies on the eastern part of S.Miguel island and is one of the most active central volcanoes of the Azores archipelago. Its volcanic activity has been essentially explosive erupting materials of trachytic composition. During its eruptive history large scalecaldera collapse episodes occurred and at least two major calderas can be identified. Several pumice cones, maars and trachytic domes are related with intracaldera activity while scoria cones formed during strombolian eruptions are located on the northern and western flanks of the volcano. The main tectonic structures on this region show a strong relation with (1) the distribution of volcanic vents, (2) the dispersal axis of pyroclastic flows, surges, lahars and lava flows, and (3) the morphology of both calderas.​