Geology of El Hierro, Canary Islands

 

El Hierro is the smallest island of the Canary Islands, but this doesn’t make it less interesting. Its landscape varies from volcanic craters to green prairies with pine forests, and the views it offers are truly breathtaking.

During the last decades, it has been recognised that the geological map of the southern rift zone of the island is incomplete and needs to be updated. This work is the first step towards a wider geological cartography of the whole island and will be a valuable tool for a better volcanic hazard assessment and monitoring, as well as urban planning.

This article presents the results of a geological modelling procedure using GeoModeller software to define the geometry of the different volcanic formations of the island of El Hierro. In particular, surface, volume and centre of mass estimations have been obtained for each of the identified sub-units of the southern rift zone, as well as for the main geological units of the island. This information has allowed us to define a scheme of stratigraphic relationships and a generalized geological history for the island.

The geological sequence of the island of El Hierro is dominated by basaltic volcanoes. These have been emitted during a series of strombolian eruptions and are characterised by their lava flows, tephrite lavas, basanites and pyroclastic cones. The volcanic sequence is divided into three geological domains, each representing a specific stage in the evolution of the volcano.

These soils are deep and fertile, with a high organic content. They are found on fans and mountain slopes, as well as valley side slopes, and have a favourable climate. They are also rich in humus, with a high nitrogen and phosphorous content. The most important mineral of this type is iron, which is why it is also known as “ferric soil”.

This type of soil is characterized by its Venta de hierros depth, fertility, and its permeability. Its deep profile and good drainage have made it a popular farming choice, but its high nutrient content also makes it ideal for urbanisation. It is also suitable for the horticultural industry.

Hierro is an Arrancar technique in which the user's spiritual power condenses, forming a steel-hard skin that can block even released Zanpakuto. It is a powerful technique, and Nnoitra Gilga once claimed that his was the strongest in the world, despite being outranked by four Espada of higher rank. However, Kenpachi Zaraki was able to break through Nnoitra's Hierro by adapting his own Spiritual Pressure.

This tiny 'hotelito' atop a wave-lashed outcrop is a ray of sunshine in El Hierro's somewhat dismal fine-dining scene. Its interiors evoke the island's pastoral heritage with an eclectic mix of modern, vintage and rustic styles. The menu is similarly varied, featuring local seafood and dishes influenced by Spanish, Colombian and Asian cuisines. It is a must-visit for anyone looking for a peaceful stay on this magical island.