Alps: Encyclopedia II - Alps - Geology

Alps - Geology

The Alps arose as a result of the pressure exerted on sediments of the Tethys Ocean basin as 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 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 landscape seen today is mostly formed by glaciation during the past two million years. At least five ice ages have done much to remodel the region, scooping out the lakes and rounding off the limestone hills along the northern border. Glaciers have been retreating during the past 10,000 years, leaving large granite boulders scattered in the forests in the region. As the last ice age ended, it is believed that the climate changed so rapidly that the glaciers retreated back into the mountains in a span of about 200 to 300 years.

Adapted from the Wikipedia article "Geology", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki