Tertiary hill country
The Tertiary Hill Country , also Tertiary Hill Country , is a climatically moderate hill country of the northern Alpine foothills , which extends north to the Danube . It is divided into two simply connected areas, which are separated from each other by the (mostly not counted) valley of the Lower Inn . In Germany (Bavaria) lies the Lower Bavarian hill country as the larger northwest part, in Upper Austria lies the Hausruckviertler mountain and hill country (also: Upper Austrian hill country ). In terms of natural space , it represents one or two large third-order regions , depending on the definition .
The tertiary hill country is framed to the west, south and south-east by old moraine gravel plate landscapes , which also represent large regions of the 3rd order of the (northern) Alpine foreland:
- the Donau-Iller-Lech-Platte in the west
- the Isar-Inn gravel plates in the western south
- the Traun-Donau-Enns gravel plates in the east, south and east.
Emergence
While the Alps formed in the Tertiary , deposits ( molasses ) collected to the south and north of them . The area only got its hilly shape during the Pliocene .
During the Tertiary, shallow inlets repeatedly pushed into the area via the Burgundian Porte and the Vienna Basin, depositing sand and marl here. The sediments of the Upper Freshwater Molasse , which were deposited 18 to 10 million years ago, form the undulating surface of the hill country. In addition to marl, there is also Nagelfluh , from which the mountain ranges often consist.
The area remained ice-free during the ice ages . Glacier downdrafts blew the fine particles out of the gravel and deposited them on the higher parts of the tertiary hill country, which is where the fertile loess comes from, the basis of today's agriculture. The fodder farms predominate among the farms .
Soils and use
The core hill country Danube-Isar hill country , Isar-Inn hill country and Hausruckviertler mountain and hill country have a lower soil quality than the Dungau and Lower Isar valley in their slipstream as well as the confluence of the Lower Inn Valley and the Lower Traun Valley . The yield indicators often fluctuate in small areas between 40 and over 60. In the Hallertau there are brown soils with high to medium base saturation, otherwise mostly pseudo-gleyed variants of brown soils that are relatively acidic and poor in nutrients predominate. In some places there are also podsol brown earths with local stone formation , such as in the stone cart near Ortenburg .
The conquest of land penetrated the interior of the hill country from the end of the 5th century. The first clearing period was around 700, the main phase of clearing followed around 1000. After 1100, numerous hamlets emerged , some of which still characterize the area today.
Today the hill country is characterized by the predominant agricultural use, to a large extent for fodder farms , by only a small proportion of forests, hedges or fields. The original beech forests have largely disappeared. Due to the forestry use, the spruce forests predominate today, in the southeast there are also pine forests on gravelly soils. Remains of near-natural vegetation can only be found in floodplains. Overall, the forest in the tertiary hill country only takes up a fifth of the area.
Web links
- The tertiary hill country as a hydrogeological sub-area (PDF file; 172 kB)