The Molasse basin (or North Alpine foreland basin) is a foreland basin north of the Alps which formed during the Oligocene and Miocene epochs. The basin formed as a result of the flexure of the European plate under the weight of the orogenic wedge of the Alps that was forming to the south. In geology, the name "molasse basin" is sometimes also used in a general sense for a synorogenic (formed contemporaneously with the orogen) foreland basin of the type north of the Alps. The basin is the type locality of molasse, a sedimentary sequence of conglomerates and sandstones, material that was removed from the developing mountain chain by erosion and denudation, that is typical for foreland basins. Geographic location The Molasse basin stretches over 1000 kilometers along the long axis of the Alps, in France, Switzerland, Germany and Austria. The west end is at Lake Geneva, where the basin's outcrop is just 20 km wide. Further to the northeast the basin becomes wider. It forms the subsurface of the Swiss Mittelland and reaches its widest (circa 130 km) in the Bavarian foreland of the Alps. From Amstetten to Sankt Pölten the basin forms a narrow band, just 10 km wide. After that it widens again to the east. North of the Danube River it connects with the Vienna basin, and is thus connected with the Pannonian Basin further east. The region where the molasse crops out is divided into two: the Subalpine Molasse zone along the Alps and the Foreland Molasse zone further into the foreland. In the Foreland Molasse zone the molasse sediments are relatively undisturbed; in the Subalpine Molasse zone the beds are often tilted, folded and thrust over each other. Tectonic history Before the development of the Molasse basin, in the Mesozoic era, the region was covered by a shallow sea that was the northern margin of the Alpine part of the Tethys Ocean (Valais Ocean in the west, Tethys Ocean proper in the east). The Molasse basin was formed when the orogenic wedge of the forming Alps was pushed north over the European continental margin, due to the convergent movement of the European and Apulian plates during the Paleogene period. The weight of the orogenic wedge made the European plate bend downward, forming a deep marine foredeep. In the Eocene epoch (55 to 34 million years ago) the basin became deeper until north of the