The Alpine orogeny occurred when the continents Africa and India and the small Cimmerian plate collided (from the south) with Eurasia in the north. Convergent movements between the tectonic plates (the Indian plate and the African plate from the south, the Eurasian plate from the north, and many smaller plates and microplates) began already in the early Cretaceous, but the major phases of mountain building began in the Paleocene to Eocene. Currently the process still continues in some of the Alpide mountain ranges.
The Alpine orogeny is considered one of the three major phases of orogeny in Europe that define the geology of that continent.
he Alps form a part of a Tertiary orogenic belt of mountain chains, called the Alpide belt, that stretches through southern Europe and Asia from the Atlantic all the way to the Himalayas. This belt of mountain chains was formed during the Alpine orogeny. A gap in these mountain chains in central Europe separates the Alps from the Carpathians off to the east. Orogeny took place continuously and tectonic subsidence is to blame for the gaps in between.
The Alps arose as a result of the collision of the African and European tectonic plates, in which the western part of the Tethys Ocean, which was formerly in between these continents, disappeared. Enormous stress was exerted on sediments of the Tethys Ocean basin and its Mesozoic and early Cenozoic strata were pushed against the stable Eurasian landmass by the northward-moving African landmass. Most of this occurred during the Oligocene and Miocene epochs. The pressure formed great recumbent folds, or nappes, that rose out of what had become the Tethys Sea and pushed northward, often breaking and sliding one over the other to form gigantic thrust faults. Crystalline basement rocks, which are exposed in the higher central regions, are the rocks forming Mont Blanc, the Matterhorn, and high peaks in the Pennine Alps and Hohe Tauern.
