Grotte de la Calmette

The entrance (1.5 m x 2 m) is a small porch located about twenty meters above the stream. a low corridor followed by a crawlway (1.5 m x 0.6 m) gives access to the main network of the cavity. This consists of a large corridor formed at the expense of a NE-SW joint (blocked to the NE by a collapse cone, elevation + 8) intersected by a N-S joint. The intersection forms a crossroads from which depart: to the left, a small network that brings us not far from the surface; to the right, the N-S joint (corridor 6 x 10) ends in a large room of fine dimensions (10 x 10 x 10).

The small massif beneath which the cave runs is located between the monotonous plateau of Fons-sur-Lussan and a collapse zone marked by the E-W cliffs of Allègre, the rocks of Peyrol, of Matte Aglans, a zone whose influence it has undergone (fractures, dip of the strata).

In the terminal low points, crumbled and agglomerated in a matrix of clay, concretions attest to the violence of ancient floods.

Draining part of the plateau, the neighboring stream has used and enlarged these fractures. La Calmette is a typical sinkhole. Currently this network is entirely fossil, the surface stream itself flowing only temporarily.

The first network is accessible by a small 2-meter climb on the left; it will allow us to reach the lowest point of the cavity (- 14 m). a descending corridor of section 2 m x 2 m and SE-NW direction, intersected by two roughly perpendicular joints, opens at the ceiling of a large room (L = 7 m, W = 4 m, h = 6 m). a 4-meter step and a straight corridor (SW-SE) allow reaching the bottom of the cavity.

The second network, on the right, is formed of an ascending corridor (NW-SE) of section 3 m x 3 m, intersected perpendicularly by a second one (SW-NE) nicely decorated with concretions, at the bottom of which a digging attempt was made without great results.