Der Solnhofener Plattenkalk — ein Blaugrünalgen-Laminit

SEM-investigations of the Solnhofen Lithographic Limestone show a cyclic change of primarily calcitic sedimentation. Layers with mainly coccoid blue-green algae as rockformers change regulary with bedding planes, partly enriched with nannoplankton with a high diversity of species. The nannoplankton is mainly deposited coprogenously. The interpretation of this specific distribution of organisms, together with paleogeographical, sedimentological and biostratinomical observations, indicate a new model of the environment of the Solnhofen-Eich-stätt area. The rhythmic cycle is established by a change of hypersalinity without H₂S-conditions (the forming of single layers) and normal marine milieu (the forming of bedding planes).