Cultural layers and a paleosol of a Late Medieval settlement as proxies of environmental change and anthropogenic influence – A case study of Tula Kremlin, Russia

Abstract

An archaeological pit with a buried paleosol overlain by four cultural layers was studied at the site of Tula Kremlin (Central Russian Upland) using macro- and micromorphological, microbiomorphic and physicochemical methods. As a result, we obtained a paleoenvironmental reconstruction of landscape changes, characteristics of early human occupation stages and an explanation of why this large cultural and economic center of the late Middle Ages was located within the floodplain of the Upa River. The absence of fluvial deposits and gleyic features within the profile of the buried soil indicates that the site, confined to the basement terrace, has never been flooded. The buried soil of Tula Kremlin and the surface soils on the adjacent uplands are formed in similar loess sediments and have similar profiles. Prior to the construction of fortifications, the study site was used as a ploughland or a garden for a short period. Pedogenic features that were preserved within the cultural layers showed that cultural layer 1 (17th-18th centuries) was formed under relatively humid climatic conditions, whereas cultural layer 2 (16th-17th centuries) developed under slightly drier and cooler conditions. The paleosol buried under those cultural layers at the end of 15th- beginning of 16th centuries, as compared to the surface soil, showed clearer signs of humus accumulation and weaker greyzemic features, what allows us to reconstruct a warmer climate with drier summers during the Medieval Climate Anomaly.