Actualité volcanique, Articles de fond sur étude de volcan, tectonique, récits et photos de voyage
Par Bernard Duyck
Leaving Auvergne, on the road back to Belgium passing between Issoire and Besse, the visit of a troglodyte fortress dug in the heart of the volcanic tuff allows a beautiful discovery: the caves of Jonas.
The Jonas fissural volcano, with its aligned cinder cones, and the nearby volcano, Saint-Pierre peak, have mixed pyroclasts with the lava to form a red tuff soft enough to be dug down to a depth of 5 meters.
The cliff is 500 meters long and 100 meters high; it is the result of volcanic activity that took place between -18 and -3Ma.
The fissural Jonas volcano, with its aligned cinder cones and Saint-Pierre peak - photo © J-M M. - one click to enlarge
The cliff was first dug in the 4th century BC by the Celts, who established a sanctuary there. The Romans took over the place, then Christian monks made an oratory there.
The caves served as a refuge during the Barbarian invasions, between 850 and 915.
At the beginning of the 12th century, the knight Anet Dalmas de Jaunac, owner of the land, had a stronghold built there, capable of resisting invaders and controlling the valley.
From generation to generation, the site will prosper to pass in 1683 to the Montal-Nozières family.
The caves were classified as Historic Monuments in 1886.
Troglodyte site of Jonas - In the 10th century, an oratory became a chapel, now called Saint-Laurent church. - photo © J-M M. - one click to enlarge
Jonas' frescoes are the oldest known in Auvergne. (9°-11° century) They represent the episodes of the end of Christ's life. In a cul-de-four, a Virgin in majesty with long hands and slender fingers, seated on a cathedra, holding the child in her lap - photo © J-M M. - one click to enlarge
The frescoes of Jonas date from the 9th to the 11th century. They represent episodes from the end of Christ's life.
Only a few pigments were used: red ocher, yellow ochre, black and white (lime).
Sources:
- Sacred places – Canalblog – Saint-Pierre-Colamine – Jonas caves
- Auvergne Center France – the troglodyte site of Jonas
- Wikipedia - Caves of Jonah
Thème Magazine - Hébergé par Overblog