Aven du Ruisseau de Castanviels

The entrance opens onto a narrow Un P 10 for 8 metres. A crawl leads to the top of a Un P 20 that ends in a large vertical fault, along which shafts follow one another, separated by short meanders, down to -130. You are then in the Salle des Douze Apôtres. From there, via a 45-metre climb, you reach a 100-metre-long meander enlivened by very narrow passages. After a 10-metre climb, you emerge into a magnificent decorated alcove: the « Géagéode ». It continues as a sandy crawl currently being dug open. After -130, the main conduit continues as a Un R 4, a Un P 22 and a Un P 10. You reach an imposing 150-metre-long meander, cut by a Un P 14 and a few small steps. At -190 you arrive at the top of the imposing shaft « Dilou », 54 metres of vertical drop followed by a fine 150-metre-long meander ending at -254 m. At the top of the P 54, another descent route allows you to reach the other side of the shaft and emerges into a complex of galleries, chambers and chimneys (more than 1.5 km surveyed). The low point of the pit lies in this sector at -270 m, at the bottom of more or less convenient and often very muddy descents.

The « Géagéode » is a magnificent decorated alcove.

Sumpings of a few metres at this flooded zone.

Gothlandian (or Silurian): black platy limestones.

Source: Article from the collaborative encyclopedia Wikipédia, in French (and access to other languages) > Silurien: https://fr.wikipedia.org/wiki/Silurien