In the slate mountains south of Saalfeld, the further east you go from the western flank of the Ziegenrück Mulde, the younger the layers become. In the Saale valley from Kaulsdorf via Ziegenrück to the Bleiloch dam and in the valleys of the Sormitz and Loquitz rivers, one encounters almost exclusively the clay slates and graywackes of the Lower Carboniferous, also known as Kulm after the existing rock formation. However, the layers do not simply dip diagonally to the east under the younger ones, but are still intensively folded within themselves. The large 1st order folds, such as the Ziegenrücker Mulde, are made up of small 2nd and 3rd order folds, i.e. folds about 1 km or 50 to 100 m wide.
The Kobersfelsen shows the typical tectonic structure of the Thuringian Slate Mountains in the area of the Ziegenrücker Mulde.