Quaternary terrains deposited on the Saharan platform, whether on the Dahar plateau or to the east in the continental Jeffara plain, cover a time interval ranging from the Lower Pleistocene to the present. They are controlled by climatic conditions and essentially correspond to three types of deposits:

Due to the uplift it underwent starting from the end of the Cretaceous and the subsidence of the maritime Jeffara, the emerged Saharan platform was the site of intense erosion during the Cenozoic.

Thus, the only Tertiary terrains known on the Saharan platform are Neogene sands encountered by drilling in the Nefzaoua region near Chott el Jerid in Southwestern Tunisia.

Above the essentially clay-sandy "Continental Intercalaire" series lies a 500-meter-thick carbonate layer, dating from the Upper Albian to the Campanian. This forms the backbone of the Dahar plateau and represents the last marine sediments deposited on the Saharan platform before its final emergence. These carbonate deposits, largely transgressive over the underlying Mesozoic and Paleozoic series, materialize the widest expansion of the Tethys.

The Lower Jurassic and early Middle Jurassic (205 to 175 million years ago) are represented by the same gypsiferous series which, in the Tataouine graben, can reach a thickness of up to 1,000 meters. This is one of the most significant gypsiferous series known in the Earth's geological formations. Remarkable for its thickness and evaporitic nature, this series covers a time interval of about 40 million years (215 to 175 Ma) and marks the transition from the Triassic to the Jurassic.

At Kef Touareg, one can observe the most complete and representative Triassic series at the foot of the Jebel Rehach cliff (type section). It features three main facies:

The Sandy Triassic, at the base, is represented by a thick 900-meter series, essentially consisting of sandstones with fossil wood and red clays with some Myophoria-bearing carbonate levels. These indicate a coastal depositional environment and allow for a Lower to Middle Triassic age (Scythian to Ladinian) for this series. Of these 900 meters, only the uppermost part, known as the Kirchaou formation, outcrops. This formation begins the Mesozoic outcrops of the Saharan platform and constitutes the substrate for the Erg el Makhzen sebkha and the Smar plain as far as the right bank of Wadi Fessi.

The oldest outcrop and the only Paleozoic terrain in Tunisia is the Jebel Tebaga range in Medenine, dating to the Upper Permian. It consists of a series approximately 500 meters thick, formed by a succession of clay, sandstone, and fossiliferous carbonate layers, featuring two significant massive reef limestone bars built by sponges and corals.

These two bars, prominent in the topography, outline the monoclinal structure of Jebel Tebaga with a 30° southward dip and show an east-west alignment inherited from an ancient orogeny (Hercynian orogeny) dating to the end of the Paleozoic, about 245 million years ago.