Greywacke Zone (from greywacke, paleozoic sandstone), structural element of the Eastern Alps between the Northern Limestone Alps in the north (of which it is the geological basis) and the Central Alps in the south. It is made up of relatively soft rocks prone to weathering; the mountains are therefore round in shape, scarcely wooded and largely covered with grassland and pastures ("Grasberge", Austrian for "grassy mountains"), which makes them particularly suitable for cattle grazing and skiing. The Greywacke Zone is also home of most of the mineral resources in Austria: iron ore and copper, magnesite, graphite, talc, etc. On the Arlberg Mountain, around the town of Landeck and in the Oberinntal Valley the Greywacke Zone forms only a narrow strip, but widens at the Wipptal Valley to include large parts of the Tux Alps, the Kitzbuehel Alps and the Salzburg Slate Mountains (Dienten Mountains), the base of the Dachstein Mountain (Ramsau plateau) and other mountains in the upper Ennstal Valley as well as the Eisenerz Alps. It then runs along the Muerztal Valley, crosses the area around the Semmering Mountain and stretches out into the Vienna Basin.