Geismar GeoPath

From 1590 to 1818 (with an interruption during the Thirty Years' War, 1618-1648), copper and silver-rich ores were mined in the "copper marl" of the Lower Zechstein ("Geismar" Formation) in the area around Geismar. The ore-bearing seam was hewn by hand in tunnels up to 70 meters deep and transported to the mine shafts in wooden mine carts ("Rullwahne"). In this way, 16 tons of copper and 40 kilograms of silver could be extracted annually.

Visible landmarks still visible today are the approximately 100 well-preserved spoil heaps, which appear as small hills in the landscape. One still-open heap can be found in the Gernhauser Bach valley at the "Weißen Berge" (White Mountain), south of the "Zechenhaus" (Mine House) farmstead. Here stood the "Krallwäsche" (claw washing plant), which operated until 1818. This structure processed the ore chunks for smelting by storing, washing (in vats with rotating iron prongs powered by water), and sorting by hand. After this elaborate processing, only about 5% of the original material remained as "wash ore." The enriched, high-quality ore (the "Graupen," ore groats) was then transported for smelting. Around 1800, approximately one ton of raw copper was produced per month. On the spoil heap where the low-grade waste rock was deposited, one can still occasionally find ore fragments with copper glaze, green malachite, and fossilized Ullmannia needles (called "fly wings"). Besides Ullmannia bronni ("Frankenberg ear of corn"), finds of Pseudovoltzia and Peltaspermum from earlier times have also been recorded (see "Hohenäcker" quarry). Many plant fossils are partially preserved in calcareous concretions.

Age of the rocks: Geismar Formation: Lower Zechstein, Upper Permian (approximately 255 million years ago)