Today’s picture shows the view from Bettlachstock Mountain to the north. The fossil-bearing limestone formations named ‘Wandflue’ at the upper image margin are made of stacks of flat-lying sedimentary rock layers. This is the current knowledge about their origin:
More than 200 million years ago the area of the Jura Mountains was flooded by the primeval ocean Tethys. In the course of the following 65 million years over 1’000 m of fossil-rich sediments were deposited here. The layer structure of this process can still be seen in the cliffs in my photograph.
The formation of the Jura Mountains began in the Cenozoic Era [the ,Age of Mammals’ is Earth’s current geological era, representing the last 66 million years]. The mountain ranges were thrust forward in giant sheets in front of the rising Alps.
The fossils of the Jura were extensively studied at the end of the 18th century. The fossil-bearing limestone formations, which Alexander von Humboldt called the ‘Jura Limestone’, are the basis of the name ‘Jurassic Period’.