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The Alps form part of a Cenozoic 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 to the east. Orogeny took place continuously and tectonic subsidence has produced the gaps in between. The Alps arose as a result of the collision of the African and Eurasian tectonic plates, in which the Alpine Tethys, which was formerly in between these continents, disappeared. Enormous stress was exerted on sediments of the Alpine Tethys 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 Alpine Tethys 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 . The formation of the Mediterranean Sea is a more recent development and does not mark the northern extent of terranes originating within the African plate. ==Geologic boundaries== The Alps form a northward convex arc around their southeastern foreland basin, the Po River basin (to be precise the south is in fact their hinterland). Quaternary and Neogene sediments in this basin lie discordant over the southernmost thrust units. In the northeast, southward dipping and internally thrusted Cenozoic foreland deposits (flysch and molasse) are found. This Bavarian and Swiss foreland basin is called the Molasse basin. The foreland basin deposits are overthrusted from the south by the thrustfront of the Alpine nappes. In Switzerland the Molasse Basin is rimmed to the northwest by the Jura mountains, an external fold-and-thrust belt, which can be seen as part of the Alps geologically. The western part of the Molasse basin forms the plateau of the ''Mittelland'' between the Alps and Jura Mountains. The Jura Mountains' location is still a topic for debate. A possible tectonic factor is the north-south extensional Rhine graben to the north. The Alps continue fairly smoothly into the following related Alpine mountain ranges: the Apennines to the southwest, the Dinarides to the southeast and the Carpathians to the northeast. In the east the Alps are bounded by the Viennese Basin and the Pannonian Basin, where east–west stretching of the crust takes place. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Geology of the Alps」の詳細全文を読む スポンサード リンク
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