Potential of Scanning Electron Microscopy in the Study of Earthen Archaeological Sites of the Steppe Zone of Russia

This article aims to test the scanning electron microscopy (SEM) technique for studying earthen archaeological sites of the steppe zone of Russia. The earthen material of the Maikop culture kurgan (the 4th–3rd millennia BC) in the Western Caucasus and two “black platforms” of the Sintashta culture (the 19th–18th centuries BC) in the Southern Pre-Urals are examined using a JEOL JSM 6060 A SEM with an EX-2300 BU energy-dispersive spectrometer (JEOL, Japan). The elemental composition of the surface was determined in each instance, and variations in the structure of earthen structures were exposed based on their visibility during SEM investigations. The samples from earthen structures are unique because nearly all of their interior surfaces are covered with a clay coating of various thicknesses. The earthen “cement” used by the Maikop people to hold the stoneworks on the kurgan slopes and the cromlech at its base was characterized by particularly smoothed clay forms, consolidated structure, and a comparatively high content of Al and a low content of Si in the clay coating. In contrast, the material inside the kurgan had a higher Si content, a looser structure, and a fragmented clay coating. It is revealed that the two “black platforms” of the Suntashta culture have different structures; one of them was looser, while the other was consolidated and essentially monolithic (“stone-like”), and the elemental composition of its substance has shown an increase in Al and Fe concentration. In terms of building technology, the SEM studies have allowed us to assume that the sedimentation process contributed to the formation of smooth (clay-based) surfaces of earthen structure fragments in the Maikop kurgan and that the application of specific compaction techniques produced an artificial stone-like body of the black platform of the Sintashta culture. The use of all these techniques preserved earthen burial structures for several thousand years.