The Sete Cidades Volcano presented the highest eruptive frequency during the last 5000 years in São Miguel Island, Azores. 17 intracaldeira eruptions, with magmatic and/or hidromagmatic characteristics, occurred during that period. One of the largest volcanic events produced by Sete Cidades Volcano during the last 5000 years occurred at about 2220 years ago and corresponds to the Sete-P11 deposit.
This work discusses the eruptive history of that eruption based on the stratigraphy and the internal characteristics of Sete-P11 deposit. Two different units were distinguished: the first, and main unit (U1) is a homogeneous pumice fall lapilli layer representing a pure magmatic eruptive phase; the second unit (U2) is an alternation of ash and lapilli layers interpreted as the result of a hydromagmatic phase.