Sunken Roads and Palaeosols in Loess Areas in Lower Austria: Landform Development and Cultural Importance

Loess, a light-yellowish sediment composed of silt-sized material, takes up a large proportion of the northeast of Lower Austria and is full of surprises of cultural and scientific importance. On the one hand, the presence of loess results in a particular set of landforms such as loess dells, gullies, sunken roads and sinkholes of both natural and anthropogenic origin. On the other hand, the many outcrops of loess with several metres of height still reveal unprecedented insights in the climatic and settlement history of Lower Austria. Both, sunken roads and palaeosols may be seen as silent witnesses of past landscape changes but on a very different time scale. Originating from a natural gully erosion process, sunken roads evolved from gullies by their transformation in access paths leading to agricultural fields. Many driving forces influenced the vertical and lateral erosion of sunken roads, which showed increasing erosion rates of up to 15-30 cm per year until the mid-twentieth century. Nowadays, many sunken roads have disappeared and many remaining ones are paved or protected from further erosion and are transformed to cellar lanes (sunken roads with wine cellars dug next to each other into the loess wall). Results from analysing the ages of palaeosols found in Lower Austrian loess profiles are internationally important. Still to the day, with upcoming new dating methods and the chance for more detailed analysis, new insights into the stratigraphy, the related ages, palaeorelief and climate oscillations are found in close collaborations of geographers and archaeologists. Many internationally important archaeological artefacts and presumably the oldest loess of Europe were found in Lower Austria.