Later stages of volcanic evolution of La Palma, Canary Islands: Rift evolution, giant landslides, and the genesis of the Caldera de Taburiente

The islands of La Palma and El Hierro form the western end of the hotspot-i nduced Canary Islands chain, Both islands are at present in the earliest an d fastest shield-building stage of growth and show many similarities with t he Hawaiian Islands. La Palma shows two very distinct phases of volcanic co nstruction: (1) a Pliocene submarine volcanic and intrusive series, interpr eted as an uplifted seamount at least 1500 m above present sea level, and ( 2) a subaerial volcanic series erupted in the past 2 m.y. Taburiente volcan o initially formed the northern part of the island and then extended to the south, forming a ridge (Cumbre Nueva Ridge) that was partially destroyed a bout 560 ha by a giant lateral collapse (the Cumbre Nueva collapse), possib ly involving 180-200 km(3) of subaerial volcanic material. The northwest bo undary of the Cumbre Nueva collapse formed a vertical scarp that, enlarged by headward erosion, formed the spectacular depression of Caldera de Taburi ente, Cumbre Vieja volcano, a north-south elongated rift, forms the souther n half of La Palma and constitutes its last stage of growth, including all eruptive activity in the past 125 k.y. Detailed field observations, mapping , and high-precision radiometric dating have allowed reconstruction of the growth and structural changes of the Cumbre Vieja volcano. Interactions bet ween eruption rates, coastal erosion, and glacio-eustatic sea level change allow stratigraphic subdivision of the edifice, The structure of the volcan o has been controlled for most of its history by a rift system with a clear ly dominant north-south and less-distinct north-east and northwest volcanic rift zones. The rift reorganization of the volcano to a single north-south rift since 7 ka and the opening of faults during the 1949 eruption probabl y reflect increasing instability of the west flank of the volcano.