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 con 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 con 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 to the conclusion that, by more chances, landslide occurred con 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. Mediante per few cases, whole logs were found paio preciso excavations carried out for remedial works or puro river erosion. Mediante 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 puro the same landslide event that, from radiocarbon dating, took place mediante a period 3195–2845 cal y BP. Durante the Cavola landslide event, con a test borehole, five different organic levels were found. From radiocarbon dating, it was possible puro reconstruct the activity of this landslide starting from its first event (the deepest sample was recovered on the sliding surface) and lasting over verso period of 1000 years. An interesting relation incontri swingingheaven 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 verso mechanism of several earth flow movements that piled up the present landslide body, each time burying the vegetation that was growing on apice of the material displaced by the previous movement.

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

The landslide provoked per damming event of per river and sometimes datable elements were found mediante the peat bogs that formed upstream from the dammed river section. This recovery case permits only a minimum age for the landslide event. However it must be underlined that the results are very useful to date those types of landslides (ed.g., rockslides) for which it is difficult puro 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 per reactivation of an ancient movement. The only available historical reference is that of Calindri (1781) who affirms that sopra an unknown time (maybe Medieval) per landslide intersected the confluence between Marano Creek and Reno River provoking the destruction of an antique thermal spa. Per per esame 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 sicuro correlate this level sicuro the presence of verso peat bog that probably developed mediante that site as per consequence of per blockage of the Reno river. The radiocarbon dating of per charcoal fragment from the organic level gives the minimum age of the landslide movement at 850 cal y B.P., durante 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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