EN
The article describes genesis and evolution of a tectonic depression in which there is the largest seasonal lake of Tunisia - the Chott Jerid. Gelogical setting of the depression and its morphometry was described with respect to geology of the whole country. The region is characterised by strike-slip faults running NW-SE, therefore the depression is of the "pull-a part" structure type. The structure began forming in upper Carbon, later it was filled with Permian and Mesozoic sediments which were folded in Neogene. At the end of Pliocene and during Pleistocene the region was probably covered by sea two times, however the second sea transgression (Tyrrhenian II) is questioned by several researchers. Evolution of the depression has been associated with many local tectonic movements which are thought to be at least 0.01 mm/yr (based on thickness of Miocene and Pliocene sediments), and later (Pleistocene and Holocene) even up to 0,26 mm/yr. Denudation rate during the whole post-orogenesis period must have been relatively high due to the arid or semi-arid climate, which favoured intensive surface wash.