New insights into the last glacial cycle in the south-eastern European Alps from the glacial geomorphological record of the Monte Cavallo (NE Italy)

Abstract

<p>Recent studies have shown that during the last glacial cycle the extent, timing and style of glaciation was not uniform across the European Alps but influenced by local topographic or climatic factors. In the south-eastern part of the mountain range, for example, glaciers not only developed in the inner-Alpine sectors but also along the pre-Alpine chains, probably fuelled by high orographic precipitation in these regions. Despite their high climatic sensitivity, the evolution of these glaciers throughout the last glacial cycle is still not fully understood and more field data are needed to enable comparisons among different sites. To address this issue, we present new results from the Monte Cavallo Group (Venetian Prealps, NE-Italy), based on detailed geomorphological mapping, glacier reconstructions and Equilibrium Line Altitude (ELA) modelling; then we compare our findings to other paleoglaciers that existed along the fringe of the southern Alps.</p><p>The oldest sediments in the Monte Cavallo Group are deposits of a small lake basin, rich in organic macrofossils such as branches and bark remains. These sediments likely date back to at least the earliest part of MIS 3, or potentially even previous interglacial periods. As climate deteriorated towards the Last Glacial Maximum (LGM), glacier tongues advanced from the peak regions into the main valleys. While towards the west, some small tributaries merged with the large Piave glacier, most of the glacial system of the Monte Cavallo remained independent. Its maximum extent is marked by prominent lateral and frontal moraine ridges that allowed reconstructing the geometry and ELA of the glaciers during the LGM. Besides the valley glaciers, also mid-altitude plateaus were at least temporarily covered by ice, however these plateau glaciers probably quickly vanished after the LGM acme, due to their restricted elevation range. Glacial retreat in the valleys, on the other hand, was intermitted by phases of stagnancy or readvance, as indicated by smaller moraine ridges up-valley. Comparing these Late Glacial moraines with other regional records may reveal important patterns regarding the early stages of post-LGM deglaciation in the south-eastern Alps.</p>