Corsica is part of Alpine Europe, but has two component parts. The west is an enormous piece of metamorphosed granite and other rocks metamorphosed by during Hercynian mountain-building, then much later, during the Eocene, Western Corsica was incorporated into Alpine Mediterranean structures. Western Corsica, with neighbouring Sardinia, was originally part of the Iberian massif, became thrust towards the east (more or less contemporaneously with the formation of the Pyrenees). Eastern Corsica comprises mostly Jurassic and Cretaceous low-grade metasedimentary rocks together with oceanic crust igneous rocks, all deformed by Alpine (‘Mid-Tertiary’) structures. This unit is related to the Italian Appenines and was thrust in from the east against western Corsica, during the Miocene. It was then subject to further rift-like extensional faulting creating a complex N-S fault belt through the centre of the island. Corsican landscapes include in the west rugged granite landscapes on which locally there is evidence of penultimate glacial action. The east is less rugged, but in both areas the rivers are entrenched. Locally, especially in the west on the margins of the mountains are alluvial fans. The Corsican coasts, especially in the west are erosional, dominently cliffed coasts.