Layer by layer – Dismantling a Yamnaya kurgan by geochemical, pedological and statistical approaches (Wallachain Plain, Romania)

Abstract

• Geoarchaeological approach combining pedological and archaeological data enhances the understanding of the construction of Yamnaya kurgans. • Palaeosoil buried at the end of the 4 th millennium BC transmits pedological information on the contemporary steppe environment. • Archaeological and geoarchaeological sources reveal and provide details on the ‘cultural re-use’ of Bronze Age Yamnaya kurgans. Kurgans are peculiar, human-made formations of the endless steppes of Eurasia. These burial mounds are not only monuments of notable botanical, zoological, pedological and geomorphological values, but as elements of the cultural heritage they also represent unique aesthetical and cultural historical significance in the landscape. Moreover, the soils under the mounds are the messengers of ancient landscape forming factors and soil generation processes. A ca. 3 m high kurgan located near the village of Boldești-Grădiștea (Romania, Prahova County) was excavated in 2019 and the cross-section, unfolding all relevant layers and buried horizons, were sampled for geochemical and pedological investigation. The sampling resolution was 5 cm. On-site soil macro-morphological description and basic soil physical and chemical methods were applied to describe the recovered (cultural) layers and soil horizons. In addition, MP-AES and ICP-MS methods were used to identify the elemental composition of the layers and horizons. Via Principal Component Analysis (PCA) and hierarchical cluster analysis patterns of the multivariate space were explored. Linear discriminant analysis (LDA) was then used to assess the probability of cluster memberships. Finally, the LDA model was applied to categorize the background samples collected from the vicinity of the mound. The information retrieved was not only used to identify construction phases, but also to distinguish various material choices during the erection and the later enlargement of the kurgan.