Growth, structure, instability and collapse of Canarian volcanoes and comparisons with Hawaiian volcanoes

Abstract

Recent onshore and offshore investigations in the Canarian archipelago, especially in the western islands of La Palma and El Hierro, have greatly improved the understanding of the genesis and evolution of these islands and allow interesting comparisons with other hotspot-induced oceanic island volcanoes, especially the Hawaiian archipelago. Genesis induced by hotspot activity and, consequently, shield and post-erosional stages of growth allow the definition of similar main stratigraphic units. The Canarian and Hawaiian volcanoes show common constructional and structural features, such as rift zones, progressive volcano instability and multiple gravitational collapses. However, the Canaries present some important geological differences from the prototypical hotspot volcanoes of the Hawaiian Islands, particularly the absence of significant subsidence; The Canarian volcanoes remain emergent until completely mass-wasted by gravitational collapses and erosion. Volcanic formations over 20 million years are observable in outcrop in the Canaries, including the seamount stages of growth in several of the islands.