“Post-rift magmatism on the Central West Margin (Estremadura Spur): new evidences from potential field data” by Cláudia Escada
Abstract: Rifted continental margins are complex geological entities, being intensively studied not only from the academic point of view but also for their economic importance, due to the occurrence of geological resources. This study is grounded in the discovery of an enigmatic geological feature located southwest of the Fontanelas volcano. This feature was identified based on new 3D seismic data offshore central Portugal, in the Estremadura Spur. Its seismic signature suggests that it might correspond to a magmatic intrusion, similar to the Sintra massif in terms of shape and areal extent. This study proposes to characterize the geometry and nature of the so-called Estremadura Spur Intrusion (ESI) and the Fontanelas volcano, based on potential field data (gravity and magnetic) modeling supported and constrained by seismic profiles. The results of this study suggest that the intrusion is predominantly gabbroic in nature, similar to a laccolith and is linked to the Late Cretaceous post-rift magmatic cycle.