 The eastern third of Franconia is dominated by the Jurassic rocks of the Franconian Jura, with the dark shales of the Black Jura, the shales and ferruginous sandstones of the Brown Jura and, the weathering-resistant limestones and dolomitic rocks of the White Jura, which stand out from the landscape and form the actual ridge of the Franconian Jura itself.In the Jura, mostly siliciclastic sedimentary rocks formed in the Cretaceous have survived.The Mesozoic sediments have been deposited in largescale basin areas.