Tettnang geo-hiking trail
The Geowanderweg Tettnang is a geological educational trail in the Tettnang Forest , which was inaugurated in June 2009 in the area of the Baden-Württemberg city of Tettnang in the Lake Constance district in Germany . At ten stations, the hiker is shown insights into the geological layers of the Tettnang Forest. The geo-hiking trail is part of the Upper Swabian geographic information network.
idea
In the course of a gravel mining permit that was extended in 2006, the geo-hiking trail was planned as part of the recultivation that became necessary and inaugurated on June 18, 2009 in the presence of District Administrator Lothar Wölfle and representatives of the application group, the Tübingen regional council and the Freiburg regional council.
location
The geology theme path is located southeast of Tettnang hamlet Hagen Book , in the Tettnang forest between the corridors Salzweg , nettle Fang , Buchbrunnen sheets , rough sheets and White Arches (gravel extraction). The easiest way to get to the first station is via the main hiking trail from the Hagenbuchen car park, past the two ponds .
course
On the board at the first station, an overview map of the route is shown and the various uses of the Tettnang Forest are explained. Stations 6 to 10 will only be set up in the near future in the area of gravel mining.
Station 2 - About dying glaciers, a giant Lake Constance and the old Argen
The ice of the Glacial Alps - glaciers melted about 17,000 years ago and formed rapidly in the deepest basin of the southern German Alpine foreland the Bodensee . The lake level, about 70 meters higher, extended into the Allgäu and far into Upper Swabia . Sands and gravel brought along by the Argen were deposited between the ice and the bank, the so-called "Tettnang Terrace".
Station 3 - wind blows over bare land
For 500 years it was once again significantly colder 12,000 years ago. The average annual temperature fell by about 5 degrees Celsius . In the area of the Tettnang Forest, the sand exposed by the lowering of the lake level was blown together in many places by the cold winds to form a dune . As the temperature rose, so did the vegetation , and the dune was stabilized by the humus layer that had formed .
Station 4 - The Tettnang Terraces
Here, at the edge that is visible today, the Upper Terrace , was the shores of Lake Constance 17,000 years ago. The Würme Ice Age glacier cleared a deep basin into which the sediments of the Argen poured out. The ice cover began to crumble as the ice warmed up and there was no supply of ice. When a barrier broke away, the water level of the lake fell and the middle terrace on which one stands here was created.
Stations 5 and 7 - Large Dead Ice Hole
Due to the increasing warming, the glacier disintegrated. The alluvial material brought by the Argen surrounded the chunks of ice and covered them. When the ice finally melted, it left holes in the landscape known as dead ice holes . The larger of the two dead ice holes that can be seen here on the geological trail is about fifteen meters deep.
Station 6 - What follows after gravel mining?
The damage caused by the gravel mining should be almost completely eliminated by the recultivation, i.e. the landscape and vegetation should resemble the original state.
Station 8 - gravel extraction and recultivation
The board at station 8 uses a map to provide information about the gravel mining in the Tettnang Forest that has been taking place since 1963. 120 hectares (ha) were approved, in 1996 a further 18 hectares were released. The last change for the time being took place in 1996: The district office granted further gravel mining under the terms of extensive recultivation measures.
Station 9 - groundwater
In this part of the Tettnang Forest, the falling precipitation can seep away through the layers of gravel. Part of it is taken through wells as drinking water for the surrounding communities, the rest flows, following the natural gradient, into the Argen and to Lake Constance. The quality of the drinking water is monitored through regular water samples.
Station 10 - Geological Window - A look inside the Tettnang Forest
Table 10 shows the different stratifications of the overburden area on a photo: At the top two meters of horizontally stored gravel and underneath it, layers of finer material that are now sloping into the former Lake Constance from the Argen.
Individual evidence
- ↑ Schwäbische Zeitung, Tettnang: New educational trail explains geology ; June 19, 2009, no.238
Coordinates: 47 ° 38 ′ 46.9 " N , 9 ° 34 ′ 43.7" E