Holocene soil formation and soil erosion at a slope beneath the Neolithic earthwork Salzmünde (Saxony-Anhalt, Germany)

Abstract

Abstract Phases of formation and erosion of Holocene soils were reconstructed based on a sequence of buried soil horizons and colluvial layers at a lower slope section beneath the Neolithic earthwork of Salzmunde, Germany. The chronology is based on eight radiocarbon ages of charcoal, soil organic matter as well as on archaeological age estimations of embedded artefacts. Until ca. 2200 BC, a chernozemic A–C-soil developed in fluvially redeposited loess. The occurrence of charcoal, the darker colour, and a shift of soil matrix radiocarbon age indicate an alteration of the upper part of the humus horizon probably related to anthropogenic activities at ca. 2200 BC. This soil was probably buried rapidly by a colluvial layer (at ca. 2200 BC). Until ca. 900 AD, a phase of less intensive land use with slope stability followed. During this phase a pedogenetic alteration — probably under forest cover in the watershed and the deposition area — of the upper part of the loess, the buried soil, and the prehistoric sediment occurred (formation of chernozem cambisol). The upper part of a dated humic crotowina fill was involved in pedogenesis as well. Soil formation is indicated by changes in soil colour (brown), pedogenic iron, clay content, the mineral assemblage of the clay fraction, and magnetic susceptibility. During medieval times (ca. 900–1500 AD), two colluvial layers with a cumulative thickness of about 1 m buried this soil. The partial destruction of the archaeological remains at the plateau started at this time. During modern times (since 1500 AD), the deposition of two colluvial layers of a cumulative thickness of about 1 m completed the sequence of Holocene slope deposits. The results imply that the chernozem at the site might have been altered by prehistoric land use and altered further into a chernozem cambisol during a phase of slope stability of about 3000 years between the Bronze Age and medieval times. The detected brunification processes took place at unexpected high rates.