Vue géologique depuis la tour d'observation (Stöffel-Park)
| Geological view from the Stöffel-lookout tower (Stöffel-Park) | |
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| Geo view at the GeoRoute Tertiär - Industrie - Erlebins Stöffel-Route | |
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| usable QR-Codes | |
| direct QR-Code: | www.qltr.de/qrka0222 |
A View into Earth's History
The view from the Stöffel Tower spans over 400 million years of Earth's history. The origin of the Westerwald lies at the bottom of the sea: during the Devonian period, massive layers of sand and mud were deposited on the floor of a sea about 300 km wide – brought in by large rivers from the supercontinent Laurussia (Euramerica), which was located to the north at the time. In the subsequent Carboniferous period, the southern continent Gondwana – to which present-day Africa belonged – moved northward and collided with the northern continent Laurussia after millions of years. During this collision, Gondwana pushed the rock layers between the continents forward like a bulldozer.
Around 320 million years ago, the Devonian sea deposits were further compressed by pressure, folded, broken, lifted above sea level, and eventually pushed onto the northern mainland. Laurussia and Gondwana together formed the new supercontinent Pangaea. The collision of the continents created a mountain range, part of which had a high mountain character. Through pressure in the Earth's crust, quartzites and schists – in part developed as slate - were formed from the sandstones and mudstones of the Devonian sea, giving the name to the Rhenish Slate Mountains, to which the Westerwald belongs.
The Rhenish Slate Mountains are a high region that has constantly been subject to weathering and erosion since its formation. A weathering cover up to 150 meters thick formed in the process. During the Mesozoic and early Cenozoic eras, these clayey weathering soils were partly re-deposited and settled in river plains and lake landscapes – the present-day clay deposits.
In the Cenozoic era, during the Tertiary period, the Westerwald began to seethe again – volcanic eruptions were frequent. Dating of the volcanic rocks shows that eruptions occurred between 28 and 5 million years ago, during which approximately 4,000 km³ of volcanic rocks were produced. The basalt of the Stöffel hill, about 25 million years old, also formed during this time.
However, the current landscape shape was not formed until the Quaternary period, also known as the Ice Age. Warm and cold climates alternated multiple times, which had lasting effects: erosion and weathering took place, and rivers and streams carved deep into the landscape. The hard volcanic rocks resisted erosion more strongly and today form the distinctive mountain peaks. The eroded debris was transported by rivers into the valleys and plains and deposited in river terraces. This process is still ongoing, as the Rhenish Slate Mountains are still slowly rising.