Geology of Fountains Of Escot

Thermal spa

Young Pyrenees

Geologically the whole Aspe valley is very interesting and is well documented. Fountains Of Escot is one of the highlights in the fascinating «Transpyrenean Geological Route».

The Pyrenees are a young mountain belt, and the buried igneous rocks are still warm, so water circulating deep in the granite is heated naturally.

Fountains Of Escot

As explained in the above geological tour, here at the Fountains Of Escot there is also another unique factor: At a depth of 2 and 3 km, there is the formation of hydrocarbons i.e. chemical reactions generating a great deal of heat and also warming up the circulating water.

The Fountains Of Escot is situated on a rare deep vertical Jurassic strata (see diagram above). Consequently a «geological fault line» is formed between the two different (Jurassic and Cretaceous) rock types thus allowing the formation of a unique selenitic thermal spring.

Thermal Waters Cycle

a) Water falls as rain at the Pyreneean peaks of the «Roumendarès» and «Trône du Roi» (east and west of Fountains Of Escot respectively).

b) Water then filters for hundreds of years until it reaches the 2-3 Km depth under Fountains Of Escot To give you an idea 3,000m is almost as high as the highest pyrenean peak! (Pico de Aneto 3,404m)

c) Here the water is naturally heated and under presure starts rising rapidly along the «geological line».

d) Finally the water resurfaces after hundreds, if not thousands, of years at a perfect temperature of 25°C ready for you!

Speleology & Archaeology

These «geological fault lines», which are the natural rising channels of the thermal springs, have recently been explored by speleologist/divers (photo above is from actual exploration).

Ample underwater caves with stalactites and stalagmites have been discovered, at the Pisciculture Spring, to a depth of 150m so far (in theory they still have, at least, another 2,000m to explore!).

The cave system and passage found has been named Apons after a local prehistoric site. See videos of the 2007 and 2008 explorations:

• Apons les Crapouillaux
• Apons 007
• Apons 011

Some of the Roman wells have also been explored and cleaned by the local speleology group. There is still a lot to be explored and discovered around these natural springs.

Note: There are guided geological tours of the Aspe valley organised by Geolval. They publish a yearly calendar of events.