Geologie – englisch

Origin of the Swabian Alb

Geology: Swabian Alb, karst rock, caves, etc.

It all began in the Jurassic period, the period from about 200 to about 140 million years ago. Today’s Europe was part of the supercontinent Pangaea and was largely covered by the Thetys Sea. Our region belonged to a tropical shallow branch of it, the Jurassic Sea. The limestone mud formed from the remains of sponge reefs, snails, mussels and other sea creatures, formed the marine deposits (sediments) as the basis for the rocks of the white Jurassic, which today make up the Swabian Alb.

From the following Cretaceous period until 65 million years ago (extinction of the dinosaurs), no traces have survived on the Alb. The area was probably mainland most of the time, temperatures were high, and the rock was worn away by natural erosion. Therefore, no traces or relics can be found of the dinosaurs that most probably roamed the landscape.

With the formation of the Alps, i.e. the submergence of the African land plate under the European land plate in the Tertiary period (65 to 2.5 million years ago), both the Black Forest and the Swabian Alb began to rise. The Alb tilted slightly to the southeast, as it still appears today. The climate was tropical, rocks were further eroded and the Alpplateau was pierced by about 350 volcanic vents. Especially in the area of Kirchheim u.T. and Bad Urach, witness mountains and craters from the period 11-17 million years ago are still clearly visible in the landscape. 

In the Pliocene, the transition from the Tertiary to the Quaternary, the age of the ice ages, the present landscape of the Swabian Alb as we know it finally emerged about 5-2 million years ago. These are deep karst valleys, karst springs such as the Blautopf, waterfalls and rugged cliffs. Not to forget, of course, the many caves, of which the Swabian Alb has around 2,700. They were formed, on the one hand, by the erosion of water and, on the other hand, by the dissolution of limestone by acidic CO2 (corrosion), the so-called karstification. During this period, the Sontheim Cave formed as a river cave system roughly parallel to the Tiefental. Today’s cave is a remnant of this system. It still impresses with its large, wide halls, interesting fissures, high shafts and impressive dripstone formations.

Norbert Klotz 

Further information in the brochure on Sontheim Cave, available at the cave ticket office.