Saturday, 14 January 2017

Light Rock in Tenerife

Tenerife, in Spain's Canary Islands archipelago, is the second largest ocean-island volcano on Earth after Mauna Loa in Hawaii. Only a 4 hour flight from the UK's provincial airports, and on the same time zone, it is a popular winter holiday destination due to its warm, sunny, sub-tropical climate.
Less than 200 miles from the African coast, Tenerife is dominated by the volcano Mount Teide, whose 3,718-metre (12,198 ft) summit is the highest point in Spain and the highest point above sea level in the islands of the Atlantic. If measured from its base on the ocean floor, it is at 7,500 m (24,600 ft) the third highest volcano on a volcanic ocean island in the world. It remains active, its most recent eruption being in 1909, and last October there were ill-informed scare stories that a major eruption was imminent.
Teide is the most visited national park in Spain and Europe and, by 2015, the eighth most visited in the world with some 3 million visitors yearly. If you can cope with the altitude the amazing lunar landscape is great hiking territory.  
Hiking in Teide National Park in 1997, under Mount Teide
The light coloured "lunar" rock in this area is ignimbrite, which is common in southern Tenerife. It has a characteristic pale yellow-orange colour and can be seen all around the southern coast, overlain with the later lava flows. 
Deposits of lava and ignimbrite above a typical basalt beach
A fine example of ignimbrite
Barbara and I returned yesterday from a week at Costa Adeje in southern Tenerife, topping up our vitamin D reserves, and it is evident in this area that just as a landscape is moulded by local geology, so is the local architecture. The UK 's beautiful Cotswolds area is famous for its buildings, made from the creamy Jurassic limestone, and southern Tenerife has ignimbrite, its Cotswold stone equivalent. As it is lightweight and easy to cut and shape, it is quarried and used locally as a building material.
A dry stone wall composed of ignimbrite
Tenerife's Ignimbrite is a pumice-dominated pyroclastic flow deposit formed from the cooling of pyroclastic material ejected from an explosive volcanic eruption around 600,000 years ago. As pyroclastic material settles it can build up thick layers, and if the temperature is sufficiently high (> 535°C) it can weld into rock, in a similar fashion to that which preserved the shapes of countless corpses after the 1st century eruption of Vesuvius. The pumice and basalt rocks that can be seen in many of the the outcrops were most likely picked up by the ground-hugging pyroclastic flow while it was cascading down the volcano's flanks.
All in all, Tenerife is a great escape from the winter blues and, if you are so inclined, also a great place to read the story of the island in the rocks.

2 comments:

  1. Great description, Barry; it seems a Geologist's paradise.
    All the best.
    Rao,T.C.

    ReplyDelete
  2. Nice write up. Thanks for sharing it.:)

    ReplyDelete

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