During the Paleogene (65 – 23 Ma), about 42-30 million years ago, the four magmatic bodies that make up the Adamello Batolite rise from the depths of the earth. And they cool below the surface, about 10 km deep in the Earth’s crust. The origin of this magma is to be attributed, according to some authors, to the fusion of the European crust. This was slipping below the Adriatic (African) crust during the Alpine orogeny. The four magamatic bodies (plutons) have decreasing ages from south to north. The oldest is the plutone of the Re di Castello (outcropping in Val di Fumo, Val di Breguzzo and Val Borzago). While the most recent is the Presanella one. The rocks outcropping today are called Tonalite and Granodiorite.