Excursion: Breitscheid | October 14, 2024
On October 14, 2024, the Panel went on an excursion with the ‘Planetary Times’ fellows to explore the geological history of a region close to Giessen: the opencast clay mine of Iphigenie Bergbau GmbH in Mahlrain, the Herbstlabyrinth Advent cave system in Breitscheid, and its neighboring Karst and Cave Trail. As our fellows specifically focus on Earth’s formation through time in their projects, the excursion marked a clear highlight in their residency.
First, we visited the Iphigenie Bergbau GmbH in Mahlrain to explore its clay mining process with a guided tour offered by its Managing Director, Mr. Berthold Müller and his wife Andrea Müller. Introduced to the raw clay deposits, the production facility with crushing and mixing units and silos, as well as through a laboratory for quality control, we were educated on the process of transforming mineral clay into defined ceramic clay mixtures. Mr. Müller informed us on the strategies they apply to mind sustainability aspects in their mining practice, such as, backfilling and recultivation of the depleted opencast mines, ensuring us that they are trying to work with the land, not simply extract from it.
On our way to the next stop, we had to wait and adjust our schedule, to make way for a herd of cows who were heading home at their own pace after a day of grazing, demonstrating to us how little they cared about the rush of the humans.
Next, the team visited the Breitscheid Cave (Breitscheidhöhle), the publicly accessible part of the Herbstlabyrinth Advent Cave System, the largest cave system in Hesse that spans 13,128 metres (as of 2024). To learn about the geomorphology of the system, we descended 125 steps down under. Mesmerized by the speleothems stalactites that were hanging down like icicles from the cave ceiling and stalagmites that were protruding from the rocky ground, illuminated by LED lights, we gained a unique insight into parts of Earth’s history.
Our guide, an avid cave explorer, informed the team on the geomorphology of the cave system. 380 million years ago, during the Devonian period, the area was located in the middle of an ocean south of the equator. With the tropical climate conditions, reef-building organisms such as corals lived on the coastal edges of volcanic islands. Thus, appeared limestone from the remains of these calcareous organisms. For millions of years, the rain and surface water enriched with carbon dioxide dissolved the limestone and weathered the rocks in a process known as karstification. This resulted in the impressive cave system and stalactites. An eight-meter long sinter curtain formed by water trickling from an overhanging rock face clearly demarcated Earth’s warm and cold periods that included two Ice Ages. We were also able to see up close fossilized teeth and bones of cave bears who were hibernating in the cave some 30,000 years ago.
Afterwards, we hiked for a while in the rain through the Karst & Cave Trail where sinkholes appeared which dissolved the limestone over thousands of years and created access to the extensive cave system.
A special thanks to Mr. & Mrs. Müller for the tour of Iphigenie Bergbau GmbH and for the delicious cakes as well as to the tour guides of Herbstlabyrinth Advent Cave System. The valuable input from the excursions would come to fruition during our fellows’ colloquium and workshop that would take place Nov. 26-29.