At the end of the Carnic (220 Ma ago - Noric), the sea cyclically covered the dry lands originating flood plains where carbon rich mud deposited. These sediments, that would later form the rocks of the “Principal Dolomia”, enveloped large bivalves, called megalodonts and preserved many dinosaur prints. The deposition of sea muds and the slow drop in the sea level, prolonged over millions of years, gave origin to the accumulation of thick layers of rock which would give origin to the towering peaks of the Dolomites (Tofana, Cristallo, Sorapìs)
A slow but relentless drop of the sea-bed (ca 195 Ma ago) formed deposits of powerful limestone banks (Lias). In the mid Jurassic (182 Ma ago) the sea bed dropped as deep as one thousand meters. This was the marine environment most suited to large shelled animals like ammonites. Therefore the sediments of this period are known as “Ammonite Red”. These were later covered by friable grey rocks, unaffected by subsequent erosion cycles, which outcrop sporadically only in some Dolomite areas: the so called “Flysch of Ra Stua” (Early Cretaceous - 120 Ma) in which shark's teeth and other fossil remains of selachians were found.
Following the thrust of the African plate, the European plates started a period of strong earthquakes and uplifting of the earth crust, which gave origin to the “Alpine Orogeny”. Few sediments were deposited in the Dolomite area since the uplifting began, but traces are found on Col Bechéi, with the “Conglomerate of Mount Parei” (25 Ma - Tertiary) the last and most recent lithologic formation of the Dolomites.