Br 5 (Br encerclé) Trou de la Pipelette

The entrance is a descending meander, narrow down to -3, then widening into a pretty sloping gallery with concretions, ledges and downcutting. Two steps and an inclined plane lead to -14 in front of a fairly narrow meander, which opens onto a blind shaft, descending to -25. Passing above this shaft, one reaches a low conduit which, after a clayey squeeze, opens into a niche with concretions; a tight crawl was then followed for 5 m, soon becoming impassable.

In the meander at -14, an enlarged passage allows the shaft to be bypassed, and by a short downclimb, to reach a ledge at -19, leaving the blind shaft which is met again at this point; one must enter a narrow step, which opens onto a short meander; calcite ledges are bypassed to reach -24 at the top of the squeeze opening onto the P 9.

The shaft, in a joint, ends in a small step; below, a joint rises to the North, leading to a small loose shaft; at the bottom of a chimney climbed for 5 m, a passage is visible 2 m higher, through a squeeze that has not been enlarged.

This whole first part of the cavity develops in blue-tinted limestone, with pebbles present in many places. The conduits of the "forced conduit" type and these pebbles suggest that the cavity may have functioned as a sinkhole.

Below the step, a loose shaft opens onto a "chamber" one wall of which is still made of blue-tinted limestone, the other being made of polygenic breccia.

Between the two, a filling of viscous clay remains in places, and in particular above a small orifice which, enlarged, opens onto the continuation, after having unpleasantly mired the caver on the way. The narrow shaft entered is made uncomfortable by an erosion blade that cuts it in two.

At the bottom, the long digging out of a very ventilated passage opened onto a P 9 through a meander that remained tight. At the bottom of the shaft, one arrives beneath a fine chimney, climbed for 17 m. At the top, two leads were explored; in both cases, the blue-tinted limestone and much more or less broken-down concretion are found again; these conduits drew air in summer, as did the lower part of the cavity.

At -55, a clayey fissure opposite the arrival of the P 9 opens onto a small shaft; a downcutting, enlarged at the bottom, opens onto two small steps with concretions; finally, a P 5 along a fault mirror was descended, followed by a 4 m downclimb. There, despite the presence of air, the cavity was abandoned at a lead barely a decimetre wide.