In Roman times, the town of Thamusida (Morocco), located along the Sebou river, was an important centre for the distribution of cereals over the empire.

The purpose of the geoarchaeological investigation conducted in 2002 for the University of Siena was to establish the paleoenvironmental framework, to identify the natural resources, to determine the agricultural land potential and to reconstruct the historical course of the river.

View over the Wad Sebou (Morocco)
View to the north from Thamusida over the Sebou river.

The site is located on the extreme northern edge of the sandy hilly landscape of the Mamora, gradually descending towards the clayey floodplain. Cereal cultivation was considered possible in the plain, and the growth of olives and grapes in the marginal areas of the hills.

The course of the river Sebou in Roman times was reconstructed by following on the aerial photographs the traces of lateral migration of the river bed, and by field survey. On the photographs, two abandoned river meanders were visible downstream of the site, of which the oldest could be assigned to Roman times. Field data showed that, over historical times, just downstream of the town there would have been a discrete erosion of the southern river shore and a corresponding advancement of the northern one, implying a lateral shifting of the Sebou of about 80 meters.

The reconstructed paleoenvironmental framework showed a landscape very similar to the present: a hill forming the northern outpost of the Mamora landscape, slightly raised above the level of the floodplain, and located along the Sebou river, whose course has since then changed in some essential points. Directly north of the site one could easily cross the floodplain, passing by an array of less swampy land, which thus formed a kind of  “valley ford”.

Thamusida (Morocco) river meanders
The two abandoned meanders downstream of the Roman town of Thamusida, the southern one is the oldest and existed probably in Roman times; in green the evident traces of river course shifting.
Thamusida (Morocca) reconstruction of the river course in Roman times
Thamusida (red star), reconstruction of the river course in Roman times, overlain on the geological map; a red line indicates the “valley ford”, following an array of less swampy land units (yellow stars).

The program Bryce was used for a 3D reconstruction of the original site, before the construction of the Roman settlement.

Reconstruction of the hill of Sidi Ali Ben Ahmed, seen from the north; vertical exasperation 6x. The trees indicate the location of the first permanent settlement. The river harbour is visible to the left. Image processed with ArcView 3.2 and Bryce 5.0.

The Roman ruins of Thamusida


Earth Sciences for Archaeology