Altmühltaler Kalksteine e.V.

Solnhofen Stone


History of Origin

Geological history places Solnhofen natural stone slightly later than the Jura limestone. Solnhofen stone was formed roughly 150 million years ago. Formed of pure lime alluvium sediments of various thicknesses ranging from 2 to 300 mm the stone is made up of 96-98% carbon acidic lime. These usable layers are called flinz, and they can reach  a total height of up to 20-50 meters in the  Solnhofen area. Those found in the Eichstätt area measure only 5-15 meters.

The sedimentation and stratification in White Jura is mainly made up of clay and lime of various thicknesses.  Flinz is defined as a technically useable layer of flagstone with a minimum thickness of 6-7 mm giving off a high pitched tone when hammered. Not usable foul stone, however, comes with a dull sound and weathers easily. Such layers are not used in production.

The biogenic elements of the stone can be seen as well preserved fossils within the layers.  As opposed to Jura limestone, in which sediments of sponges, algae and ammonites are found, the  Solnhofen stone houses the fossils of larger species of tertiary plants and animals. Aside from plants, sea animals and fish,  the well known Archaeopteryx  was found in this area. The Archaeopteryx was a dinosaur that confirmed one aspect of Darwin's theory of evolution describing it as the link between reptile and bird.