Résumé
It appears that the moist phase of the Lower Holocene came early and aridity tended to disappear in the Late Ice Age. From this point of view, the chronology of the pre-Saharian Maghreb is considerably closer to that used for the tropical Sahara. Along the same lines, the short arid phase around 7500-7000 BP is similar to what has been observed in the Sahel.On the other hand, concerning the importance of the moist phase after 7000 BP, we must look toward the European Atlantic chronology. .Along the same lines, the accumulation of the lower terrace appears for the most part to be contemporary to the "main holocene fill" of the southern French Alps.For the Prehistoric Upper Holocene, the tropical Saharan chronology becomes evanescent, due to the increase in aridity. Clues indicating a more moist climate than today have been found, however, for around 2000 and 1500 BP, in different spots in the Sahara, notably around Tibesti and in Sudan. Furthermore, the small amount of evidence currently recognized in the pre-Saharan Maghreb is not yet sufficient for a systematic comparison with the European chronology, although the clues are promising.