Baierbrunn climbing garden
The Baierbrunn climbing garden is a rock face near the municipality of Baierbrunn in the Upper Bavarian district of Munich in Bavaria .
location
The geological outcrop is located in the southern district of Munich about 1.3 kilometers northeast of Baierbrunn. It is part of the landscape protection area ordinance of the district of Upper Bavaria on the protection of parts of the landscape along the Isar in the districts of Bad Tölz - Wolfratshausen, Munich, Freising and Erding as LSG and of the fauna-flora-habitat area Upper Isar Valley .
description
Ice-age gravel on the edge of the Isar valley is exposed in the climbing garden . Except for climbers and nature lovers, this rock face is particularly important for geology . It is an important site in ice age research. In the area of the climbing garden, high-terrace gravel is laid over solidified gravel ( Nagelfluh ) from the Günz to Minde Ice Age. Low terrace gravel is just west of it. Geological organs and paleo floors are clearly visible here .
Three ice ages and two warm periods have left their geological traces here in the climbing garden. The lowest and well-consolidated ballast was first referred to in 1909 by Albrecht Penck and Eduard Brückner as "Munich ceiling ballast ". At least three ballast bodies lying one above the other must be distinguished in terms of their degree of weathering and solidification. They are interpreted as meltwater gravel from different ice ages.
While there is currently a humid and temperate climate, it was 20,000 years ago an annual average of over 10 ° C colder and much drier. This led to year-round frozen ground and enormously enlarged glaciers . In the last 2 million years this cold state alternated at least ten times with the moderate conditions.
The glaciers of the last ice age had bound a lot of rainwater in their ice, so that the water level in the oceans was up to 130 meters lower than today. From valleys in the Alps , glaciers over 1000 meters high flowed out into the Alpine foothills . They carried large masses of debris with them, which were planed from the ground and dragged along. The glaciers expanded into large, flat "ice cakes" and extended as far as the Baierbrunn area. During the ice ages, parts of the glaciers also melted in summer. The resulting floods of meltwater transported large amounts of debris towards the Danube . The rock face in the climbing garden consists of the cargo of such meltwater rivers.
The middle part of the wall lies under the light, even gravel band in the uppermost section. The upper section consists of slightly solidified melt water deposits, which is characterized by many small overhangs and horizontal niches. Underneath there are vertical, tube-like cavities. These so-called geological organs were created by weathering soft, fine-grained material.
Only the lower part of the wall is so stable that it is suitable for climbing . The increased stability is based on the lime coatings , the so-called sintered wallpapers , which are located on the rock surfaces. They come from leaking and lime-rich waters. In addition, the cementing of the individual pebbles is better overall in the lowest part of the wall. Due to the higher strength, these layers are also suitable as building material and were probably dismantled for this purpose at times.
Ice Age researchers assumed that the Munich gravel was formed during the third last Ice Age ( Mindel Cold Age ). The two gravel above originate from the next most recent of cracks or recent Würm . This structure was later reinterpreted several times and classified as older overall. The lower gravel body is now assigned to the green ice age .
hazards
The weathering can lead to stones or entire slopes falling at any time. As the boulders at the foot of the slope show, there is a risk of falling rocks or even rock falls.
Geotope
The rock face has been designated by the Bavarian State Office for the Environment (LfU) as a geoscientifically particularly valuable geotope (geotope number: 184A001). It was also awarded the official seal of approval for Bavaria's most beautiful geotopes by the LfU .
Individual evidence
- ↑ Location of the outcrop in the Bavaria Atlas (accessed on October 29, 2017).
- ↑ World Database on Protected Areas - Ordinance of the district of Upper Bavaria on the protection of parts of the landscape along the Isar in the districts of Bad Tölz - Wolfratshausen, Munich, Freising and Erding as LSG (English)
- ↑ 8034-371 Upper Isar Valley. (FFH area) Profiles of the Natura 2000 areas. Published by the Federal Agency for Nature Conservation . Retrieved November 28, 2017.
- ↑ World Database on Protected Areas - Upper Isar Valley (English)
- ^ Bavarian State Office for the Environment, Geotop Climbing Garden Baierbrunn (accessed on October 29, 2017).
- ↑ Bavaria's most beautiful geotopes, Baierbrunn climbing garden (accessed October 29, 2017)
Web links
Coordinates: 48 ° 1 ′ 41.4 ″ N , 11 ° 29 ′ 55.3 ″ E