Morphogenèse et impacts anthropiques sur les rives du Lacydon à Marseille (6000 av. J.-C. - 500 ap. J.-C.)

The North shore sediments of the ancient harbour of Marseilles reflects a complex history. As early as the Neolithic period, a noticable scouring of soils is identified and related to an extension of anthropisation. The first environnmental crisis occured arround 3 860 +/-130 B.P. (1 990-1 730 cal. B.C.). The silting of the maërl bio-accumulation and the oisters anthropic deposit will stop the maërl growth. It is a biological crisis linked with human coatal settlements. No morphological crisis is detected on the interland's hills. When Greeks colonized and founded Marseilles around 600 B.C., marine biocenosis of the north shore of the antic harbour, were strongly degraded. The successive urbanization of Marseilles' hills will lead to a major detritic crisis. The impact of anthropization is therefore determining after 600 B.C., not only on the shores but also on the hinterland. In comparison, the East shore of the harbour reveals a detritic crisis between 600-350 B.C. and a sedimentary pause during roman times. These events occured more gradually because of both the presence of coastal swamps and the peri-urban location.