Gouffre Géant de Cabrespine is part of a vast karstic system stretching from Citou to Lastours, and comprising numerous ramifications (Grottes de Trassanel, Limousis...), in which Gaougnas appears to be the major element of this vast underground system.

The lands in which develop the karstic group of Cabrespine are narrow Palaezoic limestone strips: Dilomitic limestones with golden patina dating back to Lower Devonian, Black limestones with flags and calcitic limestones with entroques dating back to Devonian Gothland. These are ancient primary lands which can be said to be between 380 to 420 million years old.

Gaougnas system developped when in contact with both lands which accounts for the difference in the morphology of the vault of the great chamber of the Gouffre Géant. It is massive and not much concretioned in the Devonian, and much concretioned in the limestones with flags more favourable for the
circulations of limestone solutions. All these rocks had more or less metamorphosed and transformed into marble.

All the karstic lands are surrounded with impermeable schists or sandstones bounding the carving out areas of caves.