Archaeological soils as archive of pedogenesis and human-landscape interactions: Classification issues and research challenges

Current knowledge about archaeological soils comes from a long-standing but sporadic collaboration between soil surveyors and archaeologists, who focused mainly on the geoarchaeological interpretation of sites stratigraphy and soil-based environmental reconstructions, whilst the classification of these soils was less approached. The aim of this work was to evaluate the ability of the current WRB system to classify archaeological soils, considering their particularities and capacity to store information on both environmental characteristics and man-landscape interactions during the pedogenesis. The focus in this paper is on the Archaic qualifier, which was introduced in WRB ten years ago specifically to describe and classify soils in archaeological context. The study was based on a single archaeological site situated in north-eastern Romania, which has a twofold historical significance: it was inhabited about five millennia ago during Cucuteni culture and it was heavily affected by warfare during WW II. The results indicated that, although the current Technosols and Anthrosols Reference Soil Groups (RSGs) are generally suitable for classifying archaeological soils, the Archaic qualifier has a narrow applicability and has been very rarely used since its allocation to the Technosols RSG. Accordingly, we proposed the supplementation of the Archaic qualifier definition, reconsideration of cambic and argic diagnostic horizons in Anthrosols and Technosols, as well as the inclusion of a new Militaric qualifier to classify warfare soils in WRB. We conclude that the classification inconsistencies are mainly related with the lack of sharply defined taxonomic criteria and research methods, which hampers the understanding of their development and spatial distribution, as well as their inventory and a better representation in the soil policy instruments.