Radiocarbon data on lateglacial and Holocene landslides in the Northern Apennines

The Emilia Romagna slope of the Northern Apennines is strewn with over 32,000 landslides, 5,000 of which are larger than 1 million cubic metres. They represent the remains of geomorphic agents that shaped the Apennines during the Holocene. Dating them by means of radiocarbon methods adds a contribution to the knowledge about the last period of the geological geomorphological history of the Apennines. They can also be used to examine the influence of Quaternary climatic changes on the instability of slopes and, for practical or planning functions, to assess the periodicity of activity phases of the landslides. The dating has been carried out on wood remnants buried under the landslide bodies. In some cases the entire tree trunk was found. In this paper we present radiocarbon dating of 20 case studies in the Northern Apennines. Results range approximately from 13790-13670 cal y BP to 950-790 cal y BP. The oldest case is that of the Morsiano earth-flow, while the younger dated event is represented by the Marano case that represents an example of how radiometric analyses can further enhance the available historical data. In the Cavola case, wood remnants of different ages were found at different depths (from 9 to 45 m), allowing the dating of the first and following periods of activity of the landslide. The results are discussed and some considerations on the correlation between landslide occurrence and Holocene climate changes are proposed.