GEOMORFOLOGIA E POPOLAMENTO ANTICO NELLA MEDIA VALLE DEL FIUME CESANO (MARCHE- ITALIA)

Abstract

Dall’Aglio P. L., Marchetti G., Nesci O., Pellegrini L., Savelli D., Calderoni G., Geomorphology and ancient settlement in
the middle Cesano river valley (Marche, Central Italy). (IT ISSN 0394-3356, 2004).
This paper reports the preliminary results obtained by comparing geomorphologic, historic and topographic data with the aim of highlighting the most significant geomorphic changes which occurred in the landscape configuration. The study area embraces the middle Cesano River valley (Adriatic side of the Marche Apennines), an area where distinct fluvial evolution stages pointed out by individual terrace levels have been identified. Starting from the so-called “3rd order” terrace alluvium (upper Pleistocene-Holocene pp. in age), several cut-and-fill stages have been recognised on the basis of field evidence, 14C dating of wood remnants and archaeological findings. Specifically, braid-plain aggradation stages characterise the most part of the upper Pleistocene terrace alluvium, whereas both late-upper Pleistocene and early Holocene deposits and terrace-surface morphology hint at a flluvial activity related to an overall meandering channel pattern. It is only in post-Roman times that braiding was at first restored and then replaced by entrenching single straight channels. Analogously, it has been verified that the physical features of the territory strictly controlled the settlement of the ancient population. Both historical and geographical constraints account for the location of the Roman town of Suasa atop a Pleistocene terrace on the right side of Cesano River. As for man-environment interaction, it is worth stressing that through the V-VI centuries a.D. a marked climatic cooling triggered an aggradation pattern in the river valley whose effectiveness was boosted because the population drop was obviously paralleled by a progressive abandonment of agriculture as well as by hydraulic workings.