The Écrins massif, whose landscapes with high and rugged reliefs result from the long and varied processes that have shaped them, is a real open book on the geological history of planet Earth. La Meije (photo), for example, is a crystalline massif overlapping the Jurassic terrains (Liassic marls) of its own cover. Its upper part formed of the crests from the Bec de l'Homme to La Meije consists of granitized gneisses of the old Hercynian chain of the Paleozoic (541 to 251.9 million years ago) that have been pushed above their old cover. This overlapping happened in the Tertiary era (66 to 2.6 million years ago) during the different phases of the Alpine folding.