Tenerife is an island of volcanic origin, whose formation began on the ocean floor some 20-50 million years.
According to one of the most recent theories the ascent of magma from the earth mantle occurs during periods of tectonic activity from faults or fractures that exist in the ocean bottom, and are the median points of the island formed during the movement of the African continent tectonic plates.
These fissure-type eruptions create the submarine or underwater pillow lavas named because they look like pillows on the ocean floor and are caused from the rapid cooling of the magma on contact with the water.
Underwater the forces are not noticeable but as the magma reaches the air the gases and steam are explosive and the eruptions are clearly visible. Accumulated materials formed the island in the late Miocene or Tertiary period.
Seven million years ago their emerged from the sea areas now called the Teno, Anaga and the Adeje Massif which is a basalt rock called Antigua Series I. Three islands formed at different times in the extreme west, east and south of Tenerife.
A second volcanic cycle called the Postmiocenas and The Recent Series II, III and IV which were much more intense and incorporated elements into the central zone of the island, which also emerge and unified the three buildings described above.
The structure formed at that time called the pre-Edificio Canadas which collapsed and rebuilt through subsequent explosions resulted in the bands on the south of the island. Subsequently on these previous explosive ruins rose other complexes called Canadas Building II rising above the 2500 meters with intense explosive processes, and rose at a rate of about 1m to begin the construction of the Cordillera Dorsal.
The construction continued with fissure-type volcanism rising from the previous building remnants. Cordillera Dorsal is the highest elevation and longitudinal development of Canary Islands, being 1600 meters high and 25 kilometres long. 800,000 years ago there were two gravitational landslides that led to the emergence of Orotava valley and Guímar. 200,000 years began the eruptions that built Pico Viejo-Teide in the centre of the island on the Caldera de Las Canadas.