The Marmitte dei Giganti in Franscia
The Marmitte dei Giganti. A majestic phenomenon, of ancient origin, but only recently discovered in Valmalenco by Giuseppe Nolli who, in 1907, found a number of singular holes in the rock along the trail from Monte dell’Ova to Franscia.
15,000 years ago, the great glaciers of Bernina flowed together into a giant tongue flowing down Valmalenco. During the summer season, the meltwater from the glacier created a number of streams, which, as they flowed downstream to the valley, carved their way through to the light.
The churning movement of the water, together with sand, pebbles and debris, worked like a giant lathe. Starting with a small weak point in the rocks, the process began a circular erosion of the area which, over time, created a number of glacier mills, also known as moulins.
The name, Marmitta dei Giganti, comes from the fact that these cavities look like large pots, and locals creatively saw them as huge casserole dishes [marmitte] used to warm up food for giants [giganti].
The Marmitte dei Giganti can be seen mainly in two areas in the Franscia basin. There is a lovely trail following the Cormor river, where this erosion phenomenon is still under way. Here visitors can see a number of rounded rocky shapes, smoothed by thousands of years of geological modelling.
Equally fascinating are the outcrops rediscovered only recently near the church of Santa Barbara, where the absence of surface water is proof that the Marmitte dei Giganti were created only by the movement of the ice around 15,000 years ago. One of the largest and most spectacular, over 3.50 meters deep, was rediscovered in 2009.
The Franscia basin and the mountains surrounding it are mostly made up of serpentine rock. This is a metamorphic rock, meaning it is derived from the transformation of another rock. With the formation of the Alpine chain, tens of millions of years ago, the collision of the continental plates (African and European), incorporated into the structure of the Alps a large fragment of the Earth’s mantle.