What questions can be answered by chemical analysis of recent and paleosols from the Bell Beaker barrow (2500–2200 BC), Central Moravia, Czech Republic?

Abstract

Mehlich 3 (M3) is the universal extraction procedure used for the analysis of plant available concentrations of many elements in agricultural and forest soils. We used this method for archaeological soils. As a huge amount of M3 background data exists, it can be used for a wide spectrum of soils and enables extraction of many elements. Using M3 together with multivariate statistics, we demonstrated the range of questions that can be answered by analysing soils from a prehistoric barrow. In soil samples collected from different barrow layers and contemporary oak wood and arable soil controls, we determined pH, organic C and total N contents and M3 concentrations of P, K, Ca, Mg, Zn, Cu, Cd and Pb. We used standardized Principal Component Analysis (PCA) to analyze the data.The dark layer beneath the barrow represented the Chernozem soil present on the site before the construction of the barrow. Natural concentrations of elements in this paleosol indicate that the area was not used for settlement, metallurgy or pottery production activities before establishment of the barrow. Chernozems were probably more widespread in the lowland regions of Central Europe in the Late Neolithic than they are today. The fertility of the paleo-Chernozem was similar to contemporary arable soil. Soil horizons characteristic of Albeluvisols and the gradual increase in soil pH and Ca concentrations with depth indicated the natural character of the barrow layers. In oak wood, Albeluvisols develop over a period longer than a century, as indicated by missing characteristic horizons in the grave pit excavated a century ago. Recent wood and arable soils were more contaminated by Pb and Cd than the paleosol, indicating modern Pb and Cd deposition.M3 extraction can be used as an international standard method for analysis of archaeological soils. Analysis of soil properties enables many questions to be answered, and therefore it should be an integral part of any archaeological research effort.