Geology of El Hierro Southern Rift, Canary Islands, Spain

The geological survey has been carried out in El Hierro with the aim to produce a new Geological Map at 1:12,500 scale for the Southern Rift. Almost 70 km(2) have been mapped providing a detailed stratigraphic and volcano-tectonic reconstruction of its evolution. Our work focused on the last Rift Volcanism phase, where hundreds of cinder cones, associated with thin lava flows, cover most of the island's surface. Lava flows fields (40), monogenetic volcanic edifices (>90), and volcano-tectonic structures (69), such as dykes, eruptive fissures, and faults have been surveyed and stored in the Geological Map. The map poses fundamental constraints on the Southern Rift geological evolution, mainly concerning its recent activity and allowing the definition of 4 main stages during the last 40 ka. Moreover, this 1:12,500 scale detailed map represents a primary tool for the volcanic hazard assessment of the Island, volcanic monitoring, urban planning, and further stratigraphic data-based investigations.

Automated summary

The geological survey in El Hierro aimed to produce a new Geological Map at 1:12,500 scale for the Southern Rift. The study mapped almost 70 km(2) and provided a detailed understanding of the stratigraphy and volcano-tectonic reconstruction of the area. The map, which includes lava flows fields, volcanic edifices, and volcano-tectonic structures, is crucial for studying the geological evolution and assessing volcanic hazards of the Island.