Tree stumps were found buried by the landslide debris

Tree stumps were found buried by the landslide debris

This occurrence can produce accurate radiometric dating of the landslide event, if the stump is still durante place. An example of this type of recovery is that of Cinquecerri: the dated stump was growing on the alluvial terrace, when it was buried by the toe of the earth flow. It was recovered with its roots still placed sopra the bedrock under the sliding surface.

Gathering together all these information, it could be affirmed that the ple of how radiocarbon dating could be crosschecked with the available historic references, leading puro the conclusion that, by more chances, landslide occurred in Medieval time

Logs were found mixed with the original earth flows that constitute the landslide body. This is the most frequent case durante the archivio elettronico of Table I. Con per few cases, whole logs were found due to excavations carried out for remedial works or sicuro river erosion. Sopra the case of Romanoro landslide, several buried tree logs were found mixed with the landslide debris. These were placed at the same level within the landslide debris, and thus they belong onesto the same landslide event that, from radiocarbon dating, took place con verso period 3195–2845 cal y BP. Mediante the Cavola landslide event, mediante verso controllo borehole, five different organic levels were found. From radiocarbon dating, it was possible esatto reconstruct the activity of this landslide starting from its first event (the deepest sample was recovered on the sliding surface) and lasting over per period of 1000 years. An interesting relation between the position of organic levels and their ages can be established: the deepest level, placed 45 m beneath the landslide surface, is the oldest, the shallowest, placed 9 m beneath the landslide surface, is the youngest. This particular situation could be explained with per mechanism of several earth flow movements that piled up the present landslide body, each time burying the vegetation that was growing on top of the material displaced by the previous movement.

The landslide took place during February 1996 per Marano (BO) causing the partial blockage of the Reno river

The landslide provoked verso damming event of per river and sometimes datable elements were found in the peat bogs that formed upstream from the dammed river section. This recovery case permits only verso minimum age for the landslide event. However it must be underlined that the results are very useful esatto date those types of landslides (di nuovo.g., rockslides) for which it is difficult preciso find organic matter within the landslide body. Good examples of this type of occurrence are the Crespino rockslide [ID10] and the Marano earthslide that is briefly described. From geomorphologic surveys it was established that this landslide was a reactivation of an ancient movement. The only available historical reference is that of Calindri (1781) who affirms that durante an unknown time (maybe Medieval) per landslide intersected the confluence between Marano Creek and Reno River provoking the destruction of an antique thermal spa. Con a controllo borehole drilled through the toe of the landslide an organic level, located under the debris and maybe displaced by the last movement, was recovered. It seemed reasonable esatto correlate this level to the presence of a peat bog that probably developed durante that site as verso consequence of a blockage of the Reno river. The radiocarbon dating of verso charcoal fragment from the organic level gives the minimum age of the landslide movement at 850 cal y B.P., sopra agreement with Calindri’s information. However the charcoal fragment could be also older than the landslide and its radiocarbon dating could represent its maximum age.

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