An Ice Age Superhighway
During the Last Glacial Maximum, around 20,000 to 26,000 years ago, the landscape of the Alps was unrecognizable. The average annual temperature was as much as 10°C colder than today, allowing a vast ice sheet to cover the mountain range. One of its most powerful components was the Adige Glacier, a massive river of ice that flowed south through the Adige Valley. At its peak, the ice in the main valley reached a thickness of 800 meters, and in some areas of the central Alps, ice thickness exceeded 2,000 meters. This immense glacier was a dynamic mass; it was a powerful agent of geological change, scraping, sculpting, and transporting rock.
As the Adige Glacier ground its way south from the high central Alps, it quarried enormous blocks of rock from the mountainsides. These rocks, frozen into the base and sides of the glacier, became passengers on a slow-motion journey. The glacier was a continental-scale conveyor belt, carrying its rocky cargo far from its origin. When the glacier reached the lower elevations where the Lessinian Alps meet the Po Valley plain, it fanned out, slowed down, and began to melt. The ice dropped its load of sediment and rock, creating a massive series of ridges called a morainic amphitheater. The Amphitheater of Rivoli Veronese is one of the most significant of these formations.