First-time evaluation and characterization of “Šarišša” mudbrick ceramics and findings by SEM–EDX and XRF: chasing the traces of fire

Šarišša is one of the most important cities of Hittite Empire in the range of 16th–twelfth century BCE. The city’s importance comes from being the Empire’s summer palace as well as castle formation is seen around the city which gives the Turkish name “Kuşakli” means “Surrounded-Belted” in English. Šarišša is said to be destroyed by a fire/incendiary or battle and almost all mudbricks were given fire and their initial structures were deformed. The fired form of these ceramics could not be identified due to different degrees of fired ceramics and their identification may also favor the provenance analysis of the region’s soil structure that is suitable for the production of mudbricks. For the analysis of mudbricks, X-ray fluorescence (XRF) analysis was evaluated first to understand the principal, compound former, and trace oxides to compare with geological soil formation and rock types. By examining XRF, the oxides were characterized for compound formation even for mineral composition. As evaluated, main oxides are SiO2, CaO, Fe2O3, Al2O3, MgO, and K2O; compound former was the volatile SO3 that has the formation possibility of gypsum as Sivas’s most provenance soil type within illite-muscovite type clays. Besides, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDX) analysis were briefly evaluated and the firing temperatures were estimated. From SEM images and EDX analysis, a very good match with XRF analysis was found by means of elemental distribution and especially Na amount was approached as glassifier by sintering of materials in the range of 800 and 1200 °C due to the glassification, vitrification, sulfate removal, and low viscosity bubble formation due to glass melting.