Аннотация:Jurassic phosphate nodules contain in fact the entire spectrum of organisms inhabiting the Jurassic sea basin (macro- and microfossils, traces and others). Decomposition of organic matter, mineralization and partial dissolution of the phosphorus in the pore waters occur in the most geochemically active upper layer of sediment, with the participation of microorganisms. Deposition centers are zones of organic remains accumulation with a high content of microorganisms which are able to accumulate and retain significant amounts of phosphorus as intracellular polyphosphate granules, while the other decomposition products - carbon dioxide, methane, etc. - are removed to the external environment. Best preservation of fossils is a result of combination of numerous factors which inhibit decay and enhance preservation, like limited permeability of sediment around the decaying organism together with precipitation of carbonate cement or clay matrix.