Monte Mongioie summit and western slopes are made of tabular, marmoreal limestone, dating back to Jurassic; on its eastern part also emerge Triassic layers of dolomitic limestone, located in a belt oriented fron North to South passing through the Bocchino dell'Aseo. On the sub-vertical cliffs near the summit and on the SW ridge of MOnte Mongioie can be noticed blackish schistose limestones, fine-grained grey dolomias and red and yellow shists.