Tufa Staircase
The small stream flowing down the valley along the Idesbach Trail reveals a geological rarity. A closer look reveals a fragile, stepped limestone structure. This tufa staircase was created by the water from the higher-lying Leitersteiner Spring. It extends horizontally for about 120 meters and vertically for 15 meters, covering both the lower part of the Lower Muschelkalk and the Voltzien Sandstone of the Upper Buntsandstein. The spring water originates from the Lower Muschelkalk and is very calcareous. It contains 1133 mg of CaCO3 per liter. As it emerges from the spring, it experiences a release of pressure and simultaneous warming. This causes the carbon dioxide (CO2), which is also dissolved in the water, to escape. This shifts the chemical equilibrium toward the limestone, which initially floats in the water in the form of tiny particles and quickly adheres to obstacles in the watercourse. As a result, limestone crusts form as the spring flows, encasing stones, plant fragments, twigs, and leaves in the streambed. This process is called calcareous sintering, and the resulting deposit is called calcareous sinter or tufa. The Leitersteiner Born is, incidentally, the source of the Itzbach ('Idesbach') stream. This tufa formation is a natural monument. Source: (Text adapted from: Wolfgang Kremer, Gisingen).