FERRUGINOUS WATER FROM THE THURAS VALLEY

Where to find petrified limestone springs

THE THURAS VALLEY, AMID WATER AND ROCKS

A pleasant, well-tended place suitable for children of all ages

In the Thuras Valley immersed in breathtaking natural scenery from which you get an idea of the complex geology of the area between Mount Courbion and Mount Chaberton and some beautiful views in the distance.

Once past the hamlet of Rhuilles, down the road leading to Thuras and Ponte Dou Turà, you will encounter the hot water springs (10°C) all year round, their waters characterised by minerals and crystals that colour the rocks they flow over red, the so-called ferruginous springs.

The particular deep red colour of the Thuras Valley springs is a natural phenomenon. Rainwater infiltrates the subsoil and circulates through permeable rocks (gypsum). The tortuous route that the water follows pushes it down into the depths; from here pressure forces it up to the surface. 

During its journey underground, the water transforms the rocks through which it flows and absorbs compounds such as calcium sulphate (gypsum) and iron, of which the subsoil is particularly rich. On the surface, the iron precipitates into the spring water in the form of oxides and hydroxides, hence the evident reddish colour. The concentration of calcium sulphate favours the reconstitution of gypsum in the form of small crystals on the iron-rich rocks themselves.