THE MOUSTERIAN-ATERIAN TRANSITION

The data about the Mousterian and the old Aterian in th Moghreb are ra re. We know however that the Mousterian looks like a Charentien of Fer rassie facies, made, as well as the Aterian which succeeds to it, by a n Homo sapiens who was not neanderthaloid. In the Aterian, known betwe en 22 000 and 45 000 years B.P., stemmed artefacts are added to a, mou sterian tradition. The geological and cultural context in which the su ccession of these two cultures happened wasn't until now known precise ly. Two interesting areas, discovered in Eastern Morocco, have given a rchaeological, geological and palaeoenvironmental data to approach thi s problem. The first, on the northern Limit of the steppic Hauts Plate aux, allowed to study three open air sites in the upper part of a Solt anian alluvial terrace. The second, in the Tetraclinis formation of th e Oujda Mountains, is the Rhafas cave, where a lone sedimentary and ar chaeological sequence belonging to the same period was found. The tran sition between Mousterian and Aterian happens during the beginning of the warm and humid interstade of Inter-Soltanian II-III (= Inter Wurm II-III) and it seems related to this climatic event, The way of life t he small groups of nomad hunters-gatherers doesn't change, nor does th eir territory; the raw material economy, the knapping of the artefacts and the retouching of the tools remain mainly the same. But the choic e of the raw materials improves, as well as the workmanship of the art efacts. Besides, stemmed artefacts appear progressively, and this tech nological mutation will cause a modification in the percentages of the main groups of tools, the cultural context remaining however the same . The Aterian appears first as a facies of the Mousterian, then as a c ultural stage.