The volcanotectonic evolution of Flores Island, Azores (Portugal)

• Autor(a) principal: Azevedo, J. M. M.
• Data de Publicação: 2006
• Outros Autores: Ferreira, M. R. Portugal
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• DOI: 10.1016/j.jvolgeores.2006.03.011
• Texto Completo: http://hdl.handle.net/10316/3936; https://doi.org/10.1016/j.jvolgeores.2006.03.011
• topic: volcanic island; volcanic complex and unit; volcanostratigraphy; subsidence and uplift

From the study and interpretation of the volcanic products and structures of Flores Island, we infer that its volcanic history was dominated by two major periods: (1) proto-insular volcanism, which includes all the submarine and emergent activities; and (2) insular volcanism, consisting exclusively of subaerial eruptions. The first period includes two phases: (1) the oldest (2.2 to 1.5 Ma) of shallow submarine volcanism; (2) the youngest (1.0 to 0.75 Ma) includes emergent volcanism. Throughout the second period, three volcanic stages are recognized: (1) the first one (0.7 to 0.5 Ma) includes the most voluminous volcanism, balanced between effusive and explosive events; (2) an intermediate stage (0.4 to 0.2 Ma) that involves a larger number of small-scale feeder centres, with effusive eruptions prevailing; (3) the third stage is the latest volcanic activity of the Island ([approximate] 0.003 Ma), with strombolian and subsequent phreatic and phreatomagmatic activity centred at four volcanic vents.