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:
- alluvial deposits,
- sebkha deposits,
- aeolian deposits, which form a nebka-type veil over the underlying terrain throughout the Saharan platform. They are particularly well developed in the west, where they form the sand dune fields of the Grand Erg Oriental, and in the northern province in the Matmata-Beni Khedache region, where they constitute significant accumulations of peridesert loess.
