The Neolithic site of Maddalena di Muccia (Umbria-Marche Apennine): a tip to reconstruct the geomorphological evolution and human occupation during the Late Pleistocene and the Holocene

The geomorphological evolution of the upper Chienti river basin, during the late Pleistocene and the Holocene, was characterized mainly by numerous landslides, strongly affecting the river dynamics, that produced falls, deviations and in some cases total obstructions with the formation of lakes sometimes extending for some kilometres. Moreover, particularly during the Holocene, phytoclastic and phytohermal travertine deposits were deposited in correspondence of steps along the river bed; one of these deposits, by means of radiocarbon dating, has been dated between 8260 100 yr BP and 7740 80 yr BP. Stromatolithic travertine is also present at the base of Holocene channels, slightly incised on the top of the upper Pleistocene alluvial plain. The Neolithic site of Maddalena of Muccia is located on an upper Pleistocene alluvial terrace, at the confluence of the two main tributaries of the river, about 400 m a.s.l. Human presence in this alluvial plain zone lasted from the ancient Neolithic to the Roman period, surely in relation to its strategic position, connecting the Adriatic and the Tyrrhenian slants of the chain. The richest and most important remains, found at just 50 cm under the field level, belong to the ancient and recent Neolithic and to the Aeneolithic, and have been collocated between the VII and the V millennium BC, using C14. During the archaeological excavations carried out by the Archaeological Superintendence of the Marche region, testimonies reveal a local economy that was primarily based on animal breeding, cereal cultivation, fishing and deforestation. The study has evidenced that the river incision process, usually started in other areas at the beginning of the Holocene, was strictly limited by the presence of steps and barrages that reduced sedimentation flows towards the initial sectors of the valleys within the calcareous Apennine ridge. The generalized deposition of travertine along the riverbeds and within the minor channels that developed at the top of the upper Pleistocene alluvial plains also produced a sort of armature of the riverbed thus limiting further erosion processes. The resumption of linear erosion coincided with the natural erosion of the dams previously caused by landslides, and above all, (starting from about 4500 yr BP) with the rapid decline of the travertine deposition due mainly to climatic conditions.