Stratigraphy of late-Holocene deposits of the ancient harbour of Marseilles, southern France

The late-Holocene stratigraphy of Marseilles harbour is presented together with archaeological evidence and radiocarbon data. An anthropogenic oyster midden, dated between c. 4260 and 3400 C-14 yr BP is followed by a period of siltation that ended the accretionary growth of an algal (marl) deposit. This event was caused by early human settlement. Subsequently the coastline was subject to progradation. It is argued here that the development of the first town of Marseilles, c. 2600 years ago, accelerated soil erosion and sediment deposition in the harbour area.