During the Cretaceous (145 – 65 Mya) the environment in western Trentino is always of a very deep sea (pelagic). The Majolica and Scaglia Rossa formations are deposited. Both are made of flint-rich limestones. At the same time, Africa’s migration towards Europe begins, due to the opening of the southern Atlantic Ocean. The ocean of the Tethys gradually closes. The formation of the Alps begins (Alpine orogeny). The seabed becomes unstable. Scaglia Rossa deposits generate submarine landslides due to seismic events. Still recognizable today at the Sasso Rosso, northern Brenta Dolomites.
In the more recent Cretaceous, the northern Alps (Austroalpine) begin to emerge from the sea and suffer erosion by atmospheric agents. Discharging the sediments deriving from the erosion of these rocks (Flysch) inside the submarine basins. In the Park area there is the Valagola Formation. Constituted by this type of deposits, formed later, between Cretaceous and Paleogene. While the similar rocks of the Bregn de l’Ors and of the Coste di Grual were formed in the Upper Cretaceous.
The transition from the Cretaceous to the Paleogene is marked by a mass extinction that leads to the end of the reptile domination on Earth.