The Helvetic nappes are thrusted over the Infrahelvetic complex and the external massifs of the Alps (like the Aarmassif or Mont Blanc Massif). In Switzerland, Germany and Austria they are also thrusted over the Molasse basin of the Alpine foreland. In turn, the Helvetic nappes were overthrusted by the Penninic nappes from the south. In Switzerland these have been eroded away at most places but in Germany and Austria they are still covering the Helvetic nappes. Due to this the Helvetic nappes only crop out as a thin band in those countries, which forms the Northern Limestone Alps.