 It is named after the Iullemmeden, a federation of Tuareg people who live in the central region of Niger.Its geographic range is largely coincident with the Azawagh region.The area of the Iullemmeden Basin seems to have started to subside in Permo-Triassic times, and to have experienced gradual downwarping during the Late Cretaceous to Paleogene times, while steadily filling with sediment.