The potential of using scanning electron microscopy with an energy dispersive analyzer for the study of the Bronze Age metal: on the problem statement

Abstract

The article is aimed at approbation of the scanning electron microscopy technique to analyse the inclusions and phase components of metallographic specimens using the results of spectral, XRF, atomic emission spectrometric, and metallographic analyses. The comparison of microstructural data with electronic images and XRSMA results in separate phases allowed identification of chemical composition of the inclusions and determination of the nature of the ores used for metallurgical processing. The article presents the results of an analytical study of the metal of the Petrovka Culture (19th–18th c. BC) of the Southern Trans-Urals using Tescan Mira 3 LMU scanning electron microscope with Oxford Instruments Analytical Ltd. Energy dispersive analyzer, implemented for determination of the elemental composition of the phases in the samples. For the analysis, metallographic specimens with the revealed microstructure of the metal were used. In the process of SEM-EDS analysis, visualisation of the surface of the specimens was performed, and the topology and structure of the metal were examined. The possibility of successful reduction of the oxide-carbonate ores without the introduction of sulphide minerals in the beginning of the 2nd mil. BC has been confirmed. It has been concluded that the presence of oxides and sulphides in the structure of pure copper is consistent with the determination of the character of ores used for smelting — oxidized or oxidized in a mixture with sulfides. The technique of identifying marker elements for the types of ores used, including As, Ni, Sb, Fe, Se, Te, has been tested. With a certain degree of probability, the types of minerals used in smelting have been determined. For the sites of the Southern Trans-Urals, where the main metallurgical centre with mines and settlements of metallurgists was located, characteristic was the use of chalcosine-covellite ores in furnace charge, apart from smelting oxide-carbonate ores. In the territory of the Middle Tobol River, in the settlements where metal processing was carried out, copper was used, obtained both from oxide ores and using chalcosine-covellite minerals from the zone of cementation of pyrite deposits.

Keywords

• southern trans-urals
• petrovka сulture
• metallurgy
• metallographic analysis
• scanning electron microscopy