Apport des dépôts endokarstiques à la reconstitution des paléo-morphologies d'un endokarst épigène : l'exemple de la grotte de la Mine de Jbel Es Serj (Tunisie centrale)

The karst of central region of Tunisia is well known by the presence of many active or fossile underground caves. However, these caves are poorly studied from a geomorphological perspective, mainly because of the requirement of specific equipment for their exploration. La Mine cave located at Jbel Es Serj represents one of the most spectacular examples of underground karst landscapes in this region. It serves as a good example of an «epigenic cave» formed through water percolation from the surface. “Epigenic speleogenesis» in the middle and lower levels of la Mine cave has resulted in four phases of carbonate deposition (speleothem), which probably correspond to humid climatic periods. The first speleothem generation (C1) dates back to the lower Pleistocene, the second speleothem generation (C2) corresponds to the middle Pleistocene, the third speleothem generation (C3) is associated with the late middle Pleistocene/ recent Holocene, and the fourth speleothem generation (C4) relates to the historical to subrecent phase. Thus, the successive phases of speleothem’deposition interspersed by several collapse generations, namely the first generation of collapsed blocks (e1), the second generation (e2), and the third generation (e3). These phases of collapse are associated with significant collapse processes related to mechanical readjustment of the cave’s ceilings and walls.