Geländeseminar Breinig nach Vicht
Recently we promoted the Lehmjoeres hike around Stolberg-Vicht on WDR TV. The village Vicht is located 2 km south of Stolberg and 5 km ESE Aachen and stretches along the river Vicht. It not only displays the strong relation of geology and industry development, but is the origin of Germany’s industrial culture, which from the Aachen-Stolberg region later moved to the Ruhr area and established the Ruhr district, Europe’s largest industrial center.
Geology: Vicht exposes yellowish Devonian carbonate rocks containing reef building stromatopores to the north, which are often used as bricks for buildings. A road cut exposes corals (cyatphyllum quadrigenium) in the quadrigenium formation in the footwall. Even older rocks can be found in siltstones along a footpath with Taeniocrada, which are remnants of a plant growing in low water. It contributed to the greatest oxygenation event in earth history which occured 400 Mio year ago (Emsian) and reflects the diversification of plants. These primitive plants by then spread from sea on land and greened the continents. They increased the oxygen content close to today’s of 21% while carbon dioxide was at app 0.3-0.4% (before industrial revolution it was app 275 ppm and now rised to app 375 ppm = 0.0375%). Hard matrix-supported conglomerates cross the village, their rough surfaces indicate sandblasting by desert storms. The age of this Vicht formation is Eifelium. These red colored, hard rocks of former wadi-type sediments are not only used as building bricks for houses but also for iron smelters in the valley. The rock bedding is now vertical at the most prominent exposure Kluckensteine, showing that the region was affected by plate tectonics. Rocks were bended and folded upright during the Variscan mountain formation in the Upper Carboniferous. Iron was mined only on the top of the surrounding hills, which was concentrated by weathering on a former peneplain in Tertiary times. Further on the Lehmjoeres hike, carbonate rocks host lead and zinc deposits and can be studied between the villages Vicht and Breinig around the Schlangenberg. Yellow Galmei violets indicate the high lead-zinc content of soil, and round holes (Pingen) point to the old mining activities. Ores deposited in the middle Devonian and lower Carboniferous carbonate rocks during extension in Jurassic and Cretaceous times.
Industry: Since medieval times the region was the center of iron production, with energy provided by charcoal from the surrounding woods of the Eifel, and further energy for air streams from the river mills. The river Vicht divided the property of the abbey of Kornelimuenster (founded in 814AC) from the duchy of Juelich (a state of in the Holy Roman empire from the 11th to 18th century) to the east. Because of better taxes and less religious restrictions, medieval iron smelters and production settled only on the eastern side of the stream. Many iron production plants were owned by the Hoesch family since medieval times, some still preserved. The family moved to the Ruhr area in the 19th century following the upcoming hard coal mining. The established Hoesch AG focused on steel and mining in the Ruhr district and Siegerland. It was taken over by Krupp AG, which later was merged to become ThyssenKrupp AG. Thyssen’s founder August also originated from the region, where his father Friedrich Thyssen managed Germany’s first wire rod factory in Aachen in the 19th century. Lead-zinc mining started before Roman times and continued until the 20th century. The region still hosts one of the world’s largest lead smelters, and is known as the world’s first brass district starting in the 16th century. While the zinc was derived locally in the Stolberg-Kelmis region, copper was imported from Mansfeld, Saxony-Anhalt. The copper yards (Kupferhoefe) established in Stolberg from 1575 onwards point to the importance of copper, the evaluation of the grade and the right mixture to make brass.
Wurm-Mulde von Roetgen nach Kohlscheid
We run a two day field trip for MSc students crossing the Inde- and Wurm-syncline near Aachen with a bicycle. On Saturday we start at the Miners Building, Aachen. Starting at Adalbert Church, built 1000 AD, we continue to Elisenbrunnen and climb the Lousberg. Further north towards Kaisersruh, we study some outcrops along the Wurm valley. After a short cut to a small exposure near Arminia Würselen’s football pitch, we continue to Teuterhof and walk up on the old railway track to our last exposure for today. Than we continue to Gouley summarizing today’s geology and discussing the old Wurm mining district. We jointly return to Kaisersruh, from which everyone makes his way home.
On Sunday we take the 8.45h line 66 from Aachen central bus station to Roetgen Wanderstation, where we start today’s field trip. On the way to Dreilaegerbach we study a road coat before continuing to the water reservoir. Further up to Struffelt Heath we have a short stop and then down to Rott we find our next exposure. Cycling through the forests we find some rocks behind Friesenrath church. Passing Friesenrath castle we continue to Walheim, which we enter from Hahn on the Eifelsteig track. Our next exposure is the small roadcut next to the parking lot of Walheim’s recreation area. We continue on the cycle path Vennbahntrasse towards Kornelimuenster. Half-way large road cuts offer a good insight into sediments and tectonics of the region. Just before reaching Kornelimuenster, another roadcut on both sides of the cycle path may offer to see varying rock types. Down to Kornelimuenster and along the Inde towards Brand we find today’s last exposure just across the bridge. After identifying the rock, measuring bedding and discussing the tectonics, we summarize the geology we’ve seen over the last two days in terms of stratigraphy, tectonics, depositional setting and economic relevance. We continue on the track, heading towards Krauthausen, but turning left on the paved road K13 Bilstermuehler Str towards Trierer Str, where we turn left to get back to the Vennbahntrasse along the Lutter Weg. Here the field trip ends and everyone makes his way home.