Internal igneous growth, doming and rapid erosion of a mature ocean island: the Miocene evolution of Maio (Cabo Verde)

Abstract Maio Island (Cabo Verde Archipelago) is composed of uplifted Early Mesozoic MORB-type pillow lavas and deep-sea sediments, unconformably overlain intruded by Miocene igneous rocks. Combined structural analyses 40 Ar– 39 Ar dating were used to constrain the evolution Maio. Structures ages sequences crosscutting dykes showed that numerous intrusive events associated with intense growth an core complex in middle upper crust, causing semi-circular doming partial disruption strata. Two nosean nephelinite cut Valanginian Batalha Formation yielded phlogopite 10.405 ± 0.033 Ma 10.570 0.053 (2σ errors). A dyke cuts overlying Aptian Morro age 9.273 0.020 Ma. existing K–Ar ages, this confirmed a main period island between ~ 16 8.7 We re-interpreted extensive polymict conglomerates, which occur below Late Monte Penoso Formation, as landslide deposits. lava clast 8.666 0.0274 Ma, represents maximum for these landslides thus confined large-scale flank collapses erosion 6.7 Flank further mass wasting during may have rejuvenated activity, i.e., resulting formation Tortonian/Messinian Malhada Pedra Formations, due decompression-induced melting at mantle depths. Such interaction volcanism be key better understand ocean worldwide.