Since their emergence in the Quaternary, about 1.8 Ma, the whole depth of Dolomite sediments has been strongly attacked by erosive agents which have shaped a diverse landscape not only on the surface, but also deep underground. Several glaciations have alternated with warmer periods and climatic changes are still ongoing. Therefore, the moulding action of the glaciers has alternated with the more incisive action of running waters.
The Ampezzo Dolomites feature several testimonies of these events: glacial cirques, some of which still bear traces of the former glacier as on Mt. Sorapis and “rock glaciers”, that is ice flows hidden by detrital layers, still dynamic as found in the Croda Rossa massif. Travenanzes and Fanes valley are among the deepest and the most eroded. Nowadays, many high waterfalls cascade down their slopes. In the same valleys, during thaws, torrents have carved deep gorges that add greatly to the charm of the scenic landscape.
In the “Ampezzo Highlands” (Fòses, Senes, and Fanes) with the outcrops of Calcari del Lias, the Karst has evolved in a spectacular way. There are many Karst formations or “Karren”, notable are the “water carved furrows” on the southern slabs of Croda del Béco. A deep, articulated system of potholes and meandering caves has been explored in the last decades. With its underground development of several kilometers and depths lower than 500 meters , the Fòses Karstic hypogean system is among the most developed.
Even in the Principal Dolomia are some caves (Tofana, Cime di Fanes), which are of considerable interest, not for their depths but for the presence of spectacular calcite concretions, the famous “Dolls of Travenanzes”, and for the fossil remains of great carnivores from the Quaternary, like the Cave Bear which made the Grotta delle Cunturìnes so famous.