Two Paleogene ocean islands are exposed in the Azuero Peninsula, west
Panama, within sequences accreted in the early-Middle Eocene. A
multidisciplinary approach involving litho-logic mapping,
paleontological age determinations, and petrological study allows
reconstruction of the stratigraphy and magmatic evolution of one of
these intraplate oceanic volcanoes. From base to top, the volcano's
structure comprises submarine basaltic lava flows locally interlayered
with hemipelagic sediments, basaltic breccias, shallow-water limestones,
and subaerial basaltic lava. Gabbros and basaltic dikes were emplaced
along a rift zone of the island. Geochemical trends of basaltic lavas
include decreased Mg# {[Mg/(Mg + Fe)] * 100} and, with time,
increased incompatible element contents thought to be representative of
many poorly documented intraplate volcanoes in the Pacific. Our results
show that, in addition to deep drilling, the roots of oceanic islands
can be explored through studies of accreted and subaerially exhumed
oceanic sequences.