Eberfinger Drumlinfeld

from Wikipedia, the free encyclopedia
Jenhausen lies in a Drumlin valley and stretches up the slopes
Small drumlin landscape near Wolfetsried
The Osterseen and the Isar foreland glacier, August Rothpletz, 1917. The Eberfinger Drumlinsfeld is located southwest of the Starnberger See

The Eberfinger Drumlinfeld is a geotope in the Upper Bavarian district of Weilheim-Schongau , southwest of Lake Starnberg . It is described as "one of the most important and extensive" or "the best known and largest" of the Drumlin fields in the Bavarian Alpine foothills and was important for research into the formation of the landscape by glaciers . It was named in 1917 by August Rothpletz after the place Eberfing .

geography

The Drumlinfeld owes its formation to the Isar-Loisach glacier from the last ice age known as the Würm Ice Age. According to its direction of movement, it is oriented roughly southeast to northwest and is located in a sub-basin between its two most important glacier tongues , which were responsible for Lake Ammersee in the west and Lake Starnberg in the east. It has a length in the direction of movement of the glacier of around 12 km and a width of around 6 km. To the north it continues as the Andechser ridge and shows the typical structures of a terminal moraine . In the south, the field is limited by terminal moraine structures that originate from the retreat phases of the glacier. In the south-east they can be assigned to the Starnberger-See-Zunge and the Seeshaupter- Terrasse , in the south and south-west various terminal moraine effects overlap to form a confused moraine landscape. The highest elevation of the Drumlinfeld is the Leitenbichel with a height of 707 m near Eichendorf.

The drumlins emerged from the marl boulder of the ground moraine of the glacier, which was given a wavy structure due to the movement of the glacier and the resulting deformation of the subsurface. The underground consists of Flinz . Drumlins occur particularly in places where the glacier broke open with crevasses because the ground relief forced it to change direction, as here with the separation of the foreland glacier into the two main tongues. Each individual drumlin has an elongated streamlined shape , the drumlins are offset from one another. The total number of hills is given as around 360, many are only very small in size, less than 100 m in length and a maximum of 60 m in width, or are fused with others in twin forms or, more rarely, even larger clusters. The distinctive structures have a length of 200 to 800 m, some of them reach considerably larger values ​​of up to 1900 m, and a width of typically 50 to 300 m, in one case even 442 m. The small forms are no longer recognizable as prominent elevations, but around 40 specimens are over 5 m and up to 46 m high. The majority of the drumlins in the Eberfinger area are now forested, however, especially in the center of the area around Magnetsried and Jenhausen , a number of knolls are exposed and are particularly easy to recognize due to their individual shape and their position in relation to one another. The location of the Drumlins on the outskirts of Jenhausen is outstanding, on which the town's church, which can be seen from afar, is located; other particularly well recognizable Drumlins are located a little south around the Wolfetsried farm.

The valley structures between the drumlins are characterized by small, often silted up lakes and moors . In them, wet meadows that are valuable in terms of nature conservation have often developed, including litter meadows with transitions to wet meadows on the one hand and small, semi- arid grasslands on the other. In some valleys there are orchids, of which the marsh stendellus is particularly important. There are moor birch and alder stocks by the waterfront , which are bordered by the pipe grass communities . The Nussberg ponds have been artificially expanded for the purpose of fish farming. The valleys drain in two main streams, the Grünbach and the Hardtbach to the Ammersee. Further, smaller valleys occur in the edge structures, including the only transverse valleys. The valley of the Grünbach is the only place in the Drumlinfeld that is deepened so deep that the flinz sands of the Upper Freshwater Molasse from the Tertiary are exposed here.

The landscape is used for small-scale agriculture and forestry, mainly in the valleys there are villages, some of which also extend to the crests of the Drumlins.

Landscape protection

The whole Eberfinger Drumlinfeld is classified as a geotope by the Bavarian State Office for the Environment . Large parts of the landscape are designated as the “Hardtlandschaft and Eberfinger Drumlinsfelder” nature reserve with an area of ​​5819.922 hectares. The Magnetsrieder Hardt is individually protected as a nature reserve because the plant communities of an extensively used pasture landscape have also been preserved on this Drumlin ridge .

A part of the Eberfinger Drumlinfeld including the Magnetsrieder Hardt with the Bernried Filzen to the east was combined as a Natura 2000 area and reported with a size of approx. 1115 ha according to the Habitats Directive . The reason given was as follows: "The area comprises the core zones of the largest Bavarian drumlin field with all of the near-natural and natural habitat types that occur in this drumlin field: various types of bog and grassland, beech and bog forests."

To the southeast of the Drumlinfeld, in the south of Lake Starnberg, the Osterseen adjoin . As ice crumbling landscapes, these are also designated as geotopes and nature reserves.

literature

  • Ludger Feldmann: The geological development of the landscape around Eberfing . In: Luise Hohenleitner: Eberfinger Heimatbuch , published by the municipality of Eberfing, 1998. Pages 255–263
  • Rolf KF Meyer, Hermann Schmidt-Kaler: Walks into the history of the earth - Volume 9: On the trail of the Ice Age south of Munich, western part . Pfeil Verlag, 2002. ISBN 3-931516-10-5 , pages 73-89
  • August Rothpletz: The Osterseen and the Isar foreland glacier . In: Communications of the Geographical Society Munich . Volume 12, Issue 2 (November 1917), pages 99-314
  • Edith Ebers: The Eberfinger Drumlinfeld. Geological and morphological study . In: Geognostic annual books . Munich 1926. Pages 47-86

Web links

Commons : Eberfinger Drumlinfeld  - collection of images, videos and audio files

Individual evidence

  1. ↑ a b Bavarian State Office for the Environment: Eberfinger Drumlinfeld (PDF; 172 kB) , Geotope Cadastre Bavaria: No. 190R039
  2. ↑ Hermann Jerz : The ice age in Bavaria . From: Geologie von Bayern , Volume 2. Schweizerbart'sche Verlagsbuchhandlung, 1993. ISBN 3-510-65157-X , pages 24 f.
  3. ↑ a b c d Ebers, 1926
  4. ↑ Rothpletz 1917, page 103
  5. ↑ Feldmann, page 260
  6. ↑ Biotope mapping Bavaria: Object 8133-0088-001. Bavarian State Office for the Environment, as of August 28, 1992
  7. ↑ Bavarian Specialized Information System for Nature Conservation: Environmental Object Catalog Bavaria LSG-00371.01 [WM-17]
  8. ↑ Bavarian State Office for the Environment: Magnetsrieder Hardt (PDF; 185 kB) , Geotope Register Bavaria, No. 190R036
  9. ↑ Natura 2000 catalog: 8133-302 Eberfinger Drumlinfeld with Magnetsrieder Hardt u. Bernrieder Filz (PDF; 20 kB), Bavarian State Office for the Environment, as of February 2008
  10. ↑ Bavarian State Office for the Environment: Osterseen ice break-up landscape , Bavaria's most beautiful geotopes

Coordinates: 47 ° 49 '  N , 11 ° 15'  E