Évent de Saint Rome

The cavity lies a few tens of metres from the Villerouge-Albas fault, which separates the Primary massif from the Eocene of the Carcassonne basin. It comprises 3 parts linked to the structure of the massif.

The entrance gallery lies on a WNW-ESE fault parallel to the major fault bounding the massif. The north-east wall consists of more or less cemented scree; a fine slickenside is visible on the opposite wall.

It continues at right angles as a fine gallery inclined at 40°, with an elliptical or even pentagonal cross-section, cut along a bedding joint; the ceiling is heavily corroded and the floor is covered with sand and pebbles.

One then reaches the main collector, a practically straight gallery (except for a small offset in the first part) oriented ENE-WSW. It develops in a fold limb (dip varying from 20 to 70°) parallel to the general direction of the beds. Narrow, rising branches, one of them 28 metres high, join the main collector. The syngenetic-type gallery displays very fine corrosion forms.

Seepage-related speleothems are observed on the south-east wall (microgours) and on the gallery floor (gours, calcite rims).

The inclined gallery ends at the first body of water, whose level is variable. The low points of the main collector are occupied by wet vaults.

The entrance gallery continues at right angles as a fine gallery inclined at 40°, which gives access to the main collector; it ends at the first body of water, whose level is variable. One then reaches the main collector.

Geology: Devono-Dinantian limestone.