The glaciers today... and yesterday
- 2 days
- April, May, June, July, August
- Natura & Benessere
Glacial pots (called Marmitte dei Giganti) dug out by the glaciers of 20 thousand years ago, lakes, gorges, the dolomite of the Brenta group and the great glaciers of the Adamello-Presanella range are the focus of this trip. Off we go! To discover the geology of the Western areas of the province of Trento, observing the traces left by glaciers during the ice ages to arrive to the glaciers of today, passing through a geological evolution of 300 million years.
• Departure in Vezzano, from the parking lot of the Valle dei Laghi theatre. Having left our car, we walk down the "Geological Path Antonio Stoppani" through the Marmitte dei Giganti southbound, visiting the "Bus di San Valentino" and the "Bus dei Poieti" glacial pots along the path.
• By car, we head to Sarche and from here we turn right on motorway SS237 to Tione - Madonna di Campiglio. At the fifth hairpin turn, we leave the car and for a short stretch we walk the trail SAT 427B, to admire the Limarò canyon from above. From here, we can also take a walk down the beautiful cycling track towards Tione and Val Rendena.
• At Ponte Arche, we continue right along the SS237 towards Tione.
• At Tione, we turn right on motorway SS239 of Val Rendena in the direction of Madonna di Campiglio and Passo Campo Carlo Magno. From Villa Rendena, Pelugo, Carisolo or Pinemonte, visitors can go for hikes on the Adamello-Presanella range. From Sant'Antonio di Mavignola and Madonna di Campiglio, instead, hikes head into the heart of the Brenta Dolomites, with different routes and levels of difficulty.
• From the pass, head down towards Dimaro and from there, to the left, take motorway SS42 that leads to Passo del Tonale, from where the lifts will take you comfortably to higher altitudes.
Of glacial origin, the Marmitte dei Giganti are holes in the rock that, owing to their moulded shape in depth and roundness, resemble huge kettles. According to tradition, Giants would drink from them to quench their thirst. The pothole-like formation is due to the whirl of water at the base of the glaciers which, mixed with pebbles and sand, has eroded the rock to form these great pits.
The spectacular geomorphological phenomena that characterise the area have always attracted the attention of many scholars, including noteworthy Abbot Antonio Stoppani, to whom the geological trail that starts off from here is dedicated. In 1875 the scientist, a scholar in geology, paleontology and glaciology, discovered the first Marmitte dei Giganti found in Italy near the village of Vezzano. He dedicated to this important discovery a whole chapter of his book "Bel Paese", a scientific divulgation masterpiece of the nineteenth century, written with a simple and colloquial language, that allowed anyone to get acquainted with the natural beauties of Italy.
It almost feels like we were in Colorado, in the United States! Among the resorts of Villa Banale di Stenico and Sarche, the waters of River Sarca have etched the Limarò gorge in the limestone rocks.
The river flows at the bottom of this impressive canyon, where we can observe ock excavation phenomena caused by the swirling movement of the water.
The Gorge is approximately 4 km long. The red and grey-coloured stratified rocks along its sheer walls are limestones formed in the Jurassic era (145-200 million years ago), when this part of Trentino was a shallow sea environment with a vast beach and inland lagoons. Just think of it: dinosaurs used to walk on this beach! Then, starting about 65 million years ago, due to the collision between the African and European Plates, the Alps began to form. Over the last millions of years, simultaneously with the upward rise of the mountains, the rivers have eroded and formed the valleys, digging deep and narrow canyons like this one into the rock.
Situated in the westernmost part of the Dolomite region, the Brenta Dolomites are an island bounded on the West by the Giudicarie valleys, on the East by Val di Non and on the North by Val di Sole. Among its highest peaks are Cima Brenta (3,150 m) and the Campanil Basso (2,883 m), one of the most famous mountains, which continues to attract mountain climbing fans. The "crode" (peaks) of the Brenta Dolomites are majestic and superb structures, moulded by erosion into spires and pinnacles of the most varied shapes. The exceptional importance of the nature, landscape and geology of this Dolomite range is protected by the Adamello Brenta Nature Park, which in 2008 became a geo-park.
The Brenta rocks cover a time span that ranges from the Triassic to the Cretaceous eras (about 185 million years). They tell the tale of a tropical archipelago, of rivers that eroded the emerged land, of a deep ocean and even of underwater landslides. Widespread is the Main Dolomite, which formed when the Brenta was a huge mudflat invaded cyclically by the tide.
The Presanella (3,558 metres high) is the highest mountain entirely located in Trentino. It is made of tonalite rock, a granite that formed from the cooling of magma within the earth's crust about 45-35 million years ago. From the earth's interior, the granite was then raised to these heights as a result of the collision between the African and European plates which led to the formation of the Alps.
In Trentino there are approximately a hundred glaciers. In the Presanella mountain range they are about 25, covering a surface of nearly 900 ha. The largest is the Presanella glacier that laps the spectacular North face of this mountain and can be seen from the road at Passo del Tonale. At the end of the Little Ice Age (1850), the front of the glacier was a good 1500 metres further ahead but now, like the rest of the Alpine glaciers, it is shrinking in size because of global warming. It is estimated to be retracting an average 20 metres each year.