In the chamber at -308m, a reascent of about 15m gave access to a fairly wide fossil canyon which blew a detectable draught. After 30m, this passage opened onto the enormous Puits de Naufragés (The Castaway's pitch), with a cross section of 15 by 25 metres and 242m deep. Near the bottom of this pitch, several inlets appeared to come from the first branch explored. The bottom of the pitch contracted to a joint-guided rift, exploration in 1976 ending at the head of a pitch estimated at 40m. (Depth 587m).
The cave continued predominantly vertical in 1977, with pitches of 54, 88, 53 and 25m to two siphons at -854m. The altitude of these sumps is 756m - the valley level.
The description is translated mainly from reference 78.2003 by Andy Waddington and Jill Gates.