The lithologies of the basement rocks are mainly gneisses, schists and amphibolites. These were in some places intruded by Permian granites after the Variscan orogeny, called Aare granite. During a late phase in the Alpine orogeny in the Tertiary the Aarmassif was uplifted in the form of a large elongated dome structure. The overlying limestones of the Helvetic nappes now have a very high dip angle, forming a ridge that appears at the Eiger and south of the Jungfrau mountain.