Reconstruction Of Late Pleistocene-Holocene Deglaciation History In The Central Italian Alps

The analysis and reconstruction of glacial fluctuations after the Last Glacial Maximum allow us to better understand the environmental and climatic changes that have occurred since then but the knowledge about their timing and extent in the mountain areas of the Alps is still limited. Four study areas have been chosen in the Italian Central Alps to run the project: the Forni, the Gavia Pass, the Stelvio Pass, and the Viola Pass Areas. Multiple methods have been used in the areas in order to obtain deglaciation ages and past glacier extents: the Iron Crystallinity Ratio (CRF) of podzols and the Schmidt’s Hammer R-values (SH) on roches moutonneés and their calibration in absolute ages, the cosmogenic techniques dating, and the analysis of peatland cores. A multidisciplinary approach is suggested to reconstruct glacial events as both the CRF and the SH have been demonstrated suitable methods for dating the glacial history. While CRF calibration may be considered regional, the local variation in calibration for SH may be due to site-specific temperature and precipitation. Eleven glacial events have been identified before the LIA: 16.7-14.7ka, 13.7ka, 12.3-11.8ka, 11ka, 10.2-9.5ka, 9ka, 7.5ka, 5.5ka, 4.1ka, 3.2ka, and 1.9-1.5ka. These events were not ubiquitarian, and happened differently in each different study area. Comparisons with other glaciers in the Alps showed that the morphology of the catchments was more important than proximity in the glacial evolution during the Holocene.