The Black Forest has a very interesting geological history. Its bedrocks are among the oldest in Germany.
Its formation began about 250 million years ago. Originally, the area of today's nature park was part of a large, shallow central European basin that was repeatedly flooded by the sea.
The bedrock of granite and gneiss that had been formed by volcanic activity during the palaeozoic era was thus covered 150 million years ago by mighty layers of red sandstone, shell limestone and keuper of up to 100 metres in thickness.
At the beginning of the cenozoic era 65 million years ago, today's mountain range was formed when the bedrock was pushed up to a height of 1000 metres. At the same time, today's upper Rhine valley was formed.
During the lifting process, the upper layers of sandstone and lime were broken up. They were then eroded by glaciers, rivers and wind or lateral landslides - with the effect that about 2.5 million years ago the bedrock was pushed up to the surface again in some parts of the Black Forest.
Today, granite and gneiss are still the characteristic rocks of the south and south-west of the nature park. At the centre, the upper geological layer consists mainly of red sandstone. In the eastern and northern nature park, this sandstone is overlaid by shell limestone on which good soil suitable for agricultural use has developed.
Geology of the nature park - Enlarge