Characterization of ceramics found in kuriki mound (Batman, Turkey) archaeological excavations

This study covers an archaeometrical characterization of 36 ancient ceramic pieces belonging to four different settlement layer unearthed in Kuriki Mound archaeological excavations carried out since 2009 with the permissions of Culture and Tourism Ministry, General Directorate of Monuments and Museums (05.06.2009 dated and No. 107818) and with the financial support of General Directorate of State. For that purpose, X-ray fluorescence (XRF), X-ray diffraction (XRD), ceramic petrography, scanning electron microscopy (SEM) in combination with energy dispersive spectrometry (EDX), Fourier transform infrared spectroscopy (FTIR), micro-Raman spectroscopy and thermal gravimetry-differential thermal (TG-DTA) analysis were performed. In context of applied methods, it is aimed to elucidate decisive parameters in discovering production processes such as microstructural characteristics, initial raw materials used and firing conditions (temperature, atmosphere, firing technique etc.). According to XRF results Na2O, MgO, Al2O3, SiO2, K2O, CaO and Fe2O3 quantities change between % 0.11-2.93, % 2.63-7.04, % 8.53-16.40, % 36.71-65.64, % 1.27-3.53, % 3.55-43.24 and % 5.05-9.45, respectively. Quartz, calcite, illite/muscovite, alkali feldspar, plagioclase, hematite, pyroxene (disopside/augite) and gehlenite are the minerals identified in various samples. Minerals like quartz, feldspar, plagioclase, illite/muscovite, calcite and dolomite which have been encountered in chemical and mineralogical phase analyses results are observed in FT-IR spectrums. Quartz and calcite which are frequently identified in XRD patterns, and also iron minerals such as hematite and magnetite which have a significant role in formation of coloring shades of the ceramics are established in micro-Raman analyses. From the back scattered electron images achieved in SEM analyses it is figured out that samples have low vitrification degree, and results of EDX analysis, which is simultaneously used with SEM, are compatible with the XRF results. As a consequence of petrographic analysis generally illitic clay mineral content is determined in samples; also quartz and plagioclase are the minerals that take place in most of the ceramics. In TG-DTA analyses, endothermic effects at the temperature range of 50 ? 150 oC that occur depending on removal of hygroscopic water, and exothermic effects at the temperature range of 150 ? 600 oC that occur due to decomposition of organic matters are detected. Additionally in some samples, that include calcite and/or dolomite, endothermic effects at the temperature range of 700 ? 850 oC which appear owing to decomposition of these carbonate minerals, and correspondingly, a significant weight loss are observed on TG curves. For all the excavation layers, in general, it is concluded that formation of new crystals or decomposition of the current crystal structures are limited due to absence of a prominent exothermic or endothermic effect on DTA curves at the temperature range of ~900 ? 1000 oC and higher temperatures. Within the framework of the obtained results, it is observed that generally illitic clay resources, quartz and plagioclases have been used in manufacture of the ceramics. It is concluded that, in all layers, the firing temperature of the ceramic bodies has not reached high temperatures such as 1000 oC ? 1100 oC, and in general, it is considered that they have been exposed to a maximum firing temperature varying in range of 700 oC ? 950 oC and therefore they have a narrow firing temperature range. Since most of the samples have no specific colorings or patterns, the occurrence of red-brown and black-gray color shades on the ceramic fractures have been interpreted as they would probably happen as a consequence of firing of iron and other organic compounds in the bodies, respectively (especially based on FT-IR and TG-DTA results). The results of the first archaeometrical research on ceramics of Kuriki Mound concluded production methods about ceramic findings dated to Late Chalcolithic period and I. millennium (Anno Domini), and provided knowledge about the socio-economic structure of archaeological settlement layers in the excavation area.