"Binsenlache" (rush tarn) in the Hasental, Pfulb
Dry valleys such as the Hasental are typical karstforms of the Swabian Alb. They developed due to flowing surface water during the Pleistocene. The Hasental valley originally drained in the direction of the prevalleys Ur-Lone and Ur-Donau (Danube). As erosion of the base level occurred inside the fragmented rocks of the Upper Jurrassic, the groundwater level fell so deep that the valleys became the dry valleys that can be seen today. All the more astonishing is to see the small wetlands with tarns (small lakes) when walking through the Hasental. This tarn (Binsenlache) is a valuable biotope which serves as a refugium for endangered ora and fauna which is therefore designated as a „Natural monument“. The development of this small wetland is a result of the volcanic vent below, on which the impermeable soil from volcanic tu retains water. The tarns you see today were installed in the frame of the land consolidation in 1976.
The Binsenlache is a Geopoint since April 2017.