IL PALEOAMBIENTE SUBBOREALE E L'IMPATTO ANTROPICO NELLA CONCA DI CAMPOCATINO: STUDIO MULTIDISCIPLINARE DI UN GEOSITO GLACIALE DELLE ALPI APUANE

The Campocatino glacial basin is one of the most emblematic and representative geosites in the Apuan Alps, regarding the evidence of glacier activity developed during the Last Glacial Maximum. This contribution aims to provide a geological-stratigraphic and paleoenvironmental evolutionary model for the Campocatino geosite, resulting from a multidisciplinary study that integrates sedimentological analysis, radiocarbon dating and anthracological analysis. The main results indicate that the Campocatino basin deposit is represented by glacial till, resedimented during the Holocene after a short transport due to surface runoff. In particular, the investigated sediments are narrowly constrained by radiocarbon dates to the time interval between 4,500 and 3,400 years ago. The composition of the analyzed deposits, characterized by the diffuse occurrence of iron-manganese nodules, support the hypothesis of their formation during a previous phase of hot and humid climate, referable to the Holocene Climatic Optimum. In the northern Apennines the development of termophilous mixed forests dominated by silver fir (Abies alba Mill.) can be traced back to the same period. As schown by the studied charcoals shown in the Campocatino area, this coniferous still persisted in the central phase of the Subboreal (3.5 ka cal BP) corresponding to the Middle Bronze Age, during the cool and wet Löbben oscillation (3.8-3.4 ka cal BP), perhaps opposing the fast rise of the beech (Fagus sylvatica L.). The abundance in the sampled deposits of small charred plant remains, allowed to introduce the discussion on the natural and/or anthropogenic origins of the repeated fires affecting the silver fir woods, which have contributed to first the rarefaction and then to the almost complete extinction of this tree in the Apuan Alps during historical times, more significantly than the colder and wetter climate changes of the Neoglaciation.