Black soils, sediments and brown calcic luvisols: A pedological description of a newly discovered neolithic ring ditch system at Stephansposching, Eastern Bavaria, Germany

Because soils reflect past physical and chemical formation conditions, they are valuable geoarchives, but the knowledge of past soil patterns is restricted. Thus, buried soils of different ages are often used to reconstruct soil development stages. Soils were analyzed at a newly discovered and excavated Neolithic ring ditch system that was constructed some 6700 years ago in east Bavaria, Germany. Sediments and newly formed soils trapped in the former 2.5 m deep ditch are compared with adjacent sediments and in situ soils. Field descriptions, thin sections and extensive laboratory analysis, together with some geophysical measurements were applied for material characterization. At the bottom of the ditch are the remnant sediments of a fully developed Calcic Luvisol, which was the main soil type about 6700 years ago at the study site. Black sediments in the upper parts of the ditch, identified as Luvic Phaeozems, might be the result of anthropogenic fire management techniques. They are termed anthropo-thermal Luvic Phaeozems. No evidence of former Chernozems, other than in positions close to the floodplain of the Danube River, were found. The formation of black soils and black sediments adjacent to brown Calcic Luvisols is documented.