The beech forests of Kellerwald National Park near Kassel belong to the largest contiguous beech forests in Central Europe. Their origins date back to the time after the last ice age, about 12,000 years ago, when the glaciers retreated northward and the forests once again conquered Europe.
Yet beneath the autumn leaves lies a far older story, a journey into the depths of Earth’s history. The rocks on which this forest grows formed more than 380 million years ago during the Devonian Period at the bottom of the long-vanished Rheic Ocean. At that time, what is now Germany lay far south of the equator in a tropical marine world between the supercontinents Laurussia and Gondwana.
An extraordinary animal world lived in this warm sea. Among coral reefs, armored fish hunted with their bizarre bony plates, alongside early sharks, coelacanths, and numerous other prehistoric fish. Some of these animals belong to the ancestors of almost all vertebrates living today, including humans.
Plate tectonics shifted the landmasses over millions of years. The Rheic Ocean disappeared as Laurussia and Gondwana approached each other and eventually collided. This collision created the Variscan Mountains – a mountain range that once reached dimensions comparable to today’s Himalayas.
The former ocean floors became deeply incorporated into this mountain-building process. The sediments of the Rheic Ocean were folded and uplifted, carrying with them the fossilized remains of its inhabitants. Thus, fossils of this prehistoric marine world can be found today in the Kellerwald – right in the midst of a German beech forest.
Over millions of years, the once-mighty mountain range was eroded by wind, water, glaciers, and weathering. The enormous mountains were transformed into today’s Rhenish Slate Mountains with their forested ridges.
Anyone walking through the fog forest of the Kellerwald today is therefore moving through several geological ages at once: across the floor of a tropical ocean whose rocks are older than the dinosaurs, and over the traces of a long-vanished mountain range.
A journey through hundreds of millions of years.
