Geology of the Alps (300 Ma), the Hercynian or Variscan orogeny, in which the supercontinent Pangaea formed from Gondwana and Laurasia, was ended. East of the terranes that now form the Alps was the Paleo-Tethys Ocean. The effects of wind and water were able to chemically and mechanically erode and destroy the Hercynic mountain ranges. In the Permian, the main deposits in Europe were sandstone and conglomerate, products of erosion in the Hercynic mountain range. At the same time, crustal extension took place because the mountain range was isostatically unstable (this is called orogenic collapse). Due to extension, basins formed along the axis of
Matterhorn plate, a small continent which broke up from Africa before the Alpine orogeny. For this reason the Matterhorn has been popularized as an African mountain. The Austroalpine nappes are mostly common in the Eastern Alps. The Swiss explorer and geologist Horace-Bénédict de Saussure, inspired by the view of the Matterhorn, anticipated the modern theories of geology: The formation of the Matterhorn (and the whole Alpine range) started with the break-up of the Pangaea continent 200 million years ago into Laurasia (containing Europe) and Gondwana (containing Africa). While the rocks constituting the nearby Monte Rosa remained in Laurasia, the rocks constituting