The detailed sedimentary study of the deposit sequences of the ancient hominid sector (SahelanthropustchadensisalisToumaï) of Toros-Menalla, presented here addresses new aspects of the sedimentary geology of the Chad Basin through an original field study of Moi- sediments. Pliocene of the northern basin of CHAD. This is an original contribution that sheds light on new knowledge of sedimentary series of fluvio-lacustrine and aeolian origin in the Djourab desert which are essential for understanding the paleoenvironments and paleoclimates of Chad, the Sahara and Africa. Aged from the Terminal Miocene to the present day, these deposits which constitute the last stages of the filling of this basin are exclusively of the continental type and concern in the broad sense the following four major sedimentary systems: fluvial, deltaic, lacustrine and aeolian. From a lithological point of view, these sedimentary series are very heterogeneous and include sandstones, sands, clays and diatomites.

Keywords: Sedimentary deposit, Djourab, Toros-Menalla, Chad, fluvio-lacustrine, aeolian