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Geology and volcanoes

 

Geology

 Quarry of basalt at Fontès - JPEG - 21.9 kb
Quarry of basalt at Fontès
Crédit CC Clermontais

What makes the centre of the Hérault department so special, and notably the Clermontais, is that over some dozens of miles there is a great variety of fantastic kinds and colours of rocks, probably unique in Europe, that attract archaeologists and geologists from all over the world. In addition to the landscape, which owes much of its picturesque aspect to its mineral support, it is more the villages with their reds, yellows, blacks, whites … which thus show off their geological particularities. This wealth of nature is to be found in the most modest rural heritage, from the numerous dolmens to the very typical peasant, dry-stone cabins (“capitelles”), not forgetting the many miles of cultivated terraces (“restanques”) which have largely contributed to the profound remodelling of the secular agro pastoral perspectives. The limestone and the dolomite, white and light grey, contrast with the red earth of the Salagou valley and its characteristic “ruffe”. The chain of volcanoes from the beginning of the first quaternary era, that cut the department from the north to the south, left black deposits of mainly ash and basalt in entire villages and in the rural landscape.

The volcanoes

At first the volcanoes in the Clermontais territory were situated at Péret, Leiuran Cabrières and Aspiran. The Malhubert volcano is a good example of Strombolian dynamism. Born 1 200 000 years ago in a lagoon area, this volcano delivered hydro (“phréatomagmatiques”) explosions which propulsed a cone of 410 feet of slag and a flow that spilt out as far as Aspiran.

At Fontès the lake of fossilized lava, started through the extraction of basalt, is a rare curiosity in the Hérault, the other one is said to be near the motorway at Salleles du Bosc (le Gèbre).

In the regions of Clermont l’Hérault, Lacoste, Brénas, Salasc, Octon and Lodève there is a concentration of volcanic buildings such as dykes, necks and basaltic flows.

A geological map will rapidly show that the lake Salagou is surrounded by these vestiges.

Volcanoes and Wildlife

The great volcanic scenery of the Auvergne is not limited to the Massif Central. A long and narrow split which goes from the Cantal up to Brescou in Agde, has allowed for the emergence of volcanoes in the Escandorgue (Carlencas), in the Lodévois (Salagou), around Paulhan, St Thibéry, and the Cap d’Agde.

Paulhan is surrounded by the arc of a volcanic circle. To the south-west, the Nizas volcano that started near Fontès spread its lava towards Lézignan la Cebe and shaped the aerodrome. The more volcanic activity approaches the sea, the more recent it is (1.4 million years ago). We speak about the inversion of the relief following the moving of the tectonic plates coming from Africa. The trickling of the waters had pushed out everything around. Thus, the waters have since time immemorial sculpted the landscape, giving birth to limestone, sand and clay

The talking walls ...

Discover the Clermontais villages differently, through geology. Go searching for the stones that made our houses. Do an initiation course in geology and national heritage. Fun for all the family. Download the different brochures about the villages from this site :

http://cesmursquinousparlen.free.fr/

Pictures

Basalt quarry at Fontès - JPEG - 167.2 kb
Basalt quarry at Fontès

Crédit CC Clermontais

Volcanic flow at Fontès - JPEG - 165.4 kb
Volcanic flow at Fontès

Crédit OT du Clermontais

The Dyke of la Roque, near Liausson - JPEG - 143.4 kb
The Dyke of la Roque, near Liausson

Crédit OT du Clermontais

A basaltic cliff at Aspiran - JPEG - 111.5 kb
A basaltic cliff at Aspiran

Crédit CC Clermontais

A thousand layers of « ruffe » around Mérifons - JPEG - 161.2 kb
A thousand layers of « ruffe » around Mérifons

Crédit OT du Clermontais

The Neck of la Roque near Liausson - JPEG - 146.7 kb
The Neck of la Roque near Liausson

Crédit OT du Clermontais

The fairy Hole, volcanic vestige at Fontès - JPEG - 124.3 kb
The fairy Hole, volcanic vestige at Fontès

Crédit OT du Clermontais

 
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