Méaudre From, head of the Domain ski Narcea. Follow the forest road until it intersects the basin of the Furon place called "Vira", where you can park. Move up the valley by the path (one that goes straight), to a large clearing. Continue on the right when we find the forest, then follows a small path that leads up the ridge. Weather permitting, the saddle is an extraordinary view over the gorges of the Bourne and the plain of Valencia. The hole lies at the foot of ledge (10m), access is visible from 50m on the left. It is better to change before heading down to the entrance (marked S2 PV).
History The cavity was discovered in 1973 and explored in 1974 by Deep Vercors (Autrans) and the GSV after unclogging the hose inlet. The topography shows a development of 1845m to -98 m depth. The siphons are explored by B. P. LEGER Dupille; one of the downstream is explored on 25m after crossing two squeezes, while the upstream is impenetrable to the rating-7m.
In 1992, Roland Tirard-Collet, Alain, and Sylvain Julien CAULLIREAU resume the input network and discover the network of Daltons. C. CLARY plunges the downstream trap in 1993 and stops at -34 m by lack of air.
In 1996, participants of the expedition 97 Melusine explore and search some of the headwaters of the river and make the crossing at the top of P31. They discover a large room and a large gallery which continues the headwaters of the river at the top of the P15 background. Gildas BRAZEAU Stéphane Cabrol and Florent DUPORT discover and explore the network's April Fools totaling 963 m development.
In 1999, Alain and Julien CAULLIREAU decide to take stock in order to understand this cavity. They resume the Topo
from the entrance, assisted by Sylvain Florent CAULLIREAU and Sophie and Serge Caillault. The network was aceto topography by Jean Charles Borel, Benedict and Nicolas Chocquet DELATY. The result is 4300 m for development - 156 m depth in late summer 2000, with more than 1200 m of new galleries found. Significant changes are made to previous surveys. A new dive
downstream of the siphon by Christopher EMERY results in failure because of large deposits of mud in the rolling start. The S5 is a siphon gur fed by the river and contains no more (It is empty by drought). The river just be very dangerous in case of flooding. A very significant rise in water was observed at the downstream siphon October 3, 1999. Also, the P31 has been retooled to allow for easier recovery in case of heavy water.
In 2002, Fred dives Poggia: See the link "an unexpected journey"
Geology 
Roche Shalva is situated in the layer of Senonian. This cavity closes on the siphon at the coquina. It appears that this is a fault that stops the network -157. Thanks to discoveries in the hole of the Heart, we now know that the trap spring 150m is a fracture in parallel, a dive by Fredo Poggia will prove this relationship. See Geology of the hole of the Heart. And in the "unexpected crossings ..."
Hydrology River Flow 5 l / s, low flow of 1 l / s. Staining on 11/24/1974 (5kg fluorescein diluted in 50% ammonia) was released 36 hours later at the source of the bridge Olivet (In La Martiniere) and then in a meadow at 30 m north-east of the temporary resurgence Olivet. The relationship between the S2 and S3 has been proven by staining with the old fluorescent June 4, 2000. The S4 is only allowed to water which dries very dry summers
... The relationship with the hole in the heart was established in 2002 by Fredo Poggia by immersing the trap ...
The result of the hydrology of the hole part of the heart ... See folder ...
s surprising inter-stratum and fault urgonian / Senonian. We now arrive at terminal 2005. Alain in the meander down on a deposit slip and fill joined a rock bridge stuck. I am, and we continue to the bottom of the meander 
