Paleoclimatic reconstruction based on studying of soils of the short-term chronosequence, buried under different constructions in the big Boldyrevo kurgan

Abstract

<p>In 2019, kurgan 1 in the Boldyrevo IV kurgan cemetery in the Orenburg region, Russia was studied. The kurgan was built by the population of the Yamnaya culture of the Early Bronze Age (about 5500 years ago). Within the kurgan, four earthen structures built-in succession have been revealed. Under each of the kurgan structures, the buried soil has been studied. According to archaeological data, the kurgan was built over several decades; radiocarbon dating showed an interval of 300 years.</p><p>During the construction of the kurgan, the morphology and physicochemical properties of the soils and materials of the kurgan structures changed, namely, the content of organic matter decreased, while the content of carbonates, gypsum, exchangeable sodium in the composition of exchangeable bases and the value of magnetic susceptibility increased. It can be suggested that the studied interval of the kurgan building, like the entire early (Repino) stage of the Yamnaya culture, was characterized as more arid in comparison with the present.</p><p>Based on the micromorphological analysis and physicochemical properties of the materials of the kurgan structures and buried soils, it can be assumed that the monument was built from local soils using anthropogenic material. The construction technology consisted of rough kneading and tamping of raw sandy loam material with the addition of river silt, rare coal dust, and bones. For facing the ritual site around the main burial river silt was exclusively used.</p><p>Previously, in the study of short-term pedo-chrono-sequences under the structures of big kurgans of the Early Bronze Age of different ages in the Stavropol and Krasnodar Territories, it has been also compared the properties of paleosols and earthen structures. It allowed confirming the use of local soils in the construction of the monuments and carrying out paleoclimatic reconstruction. In addition, for all three studied big kurgans, a comparison was made of technical and technological approaches used by ancient builders for the construction of monumental facilities of earthen architecture.</p>