The former quarry at Steinschab gives the visitor a good insight into the rock formation of the Upper Devonian (about 380 million years before today), which was uplifted by the mountain building of the Rhenish Slate Mountains and tilted by folding. Exposed are fine-grained sandstones, which form 30 - 40 cm thick rock banks. This sequence of strata is also called Nehden sandstone. Thin clay shales are partially intercalated between the benches. The sandstones show structures on the bedding planes, which were formed during deposition. Mostly wave-shaped ripple marks can be recognized. They are formed by the action of flowing water on the layer boundary of a sandy sediment. Occasionally, however, fossil plant remains can be found on the bedding planes.
Age of rocks: Nehden Sandstone: Nehden Stage, Upper Devonian (380 million years before present).