Thermal-induced changes of organic temper in archaeological ceramics visualisation with helical trajectory and high-quality X-ray CT

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1. Introduction Ceramic is a prominent archaeological material that carries a lot of information on questions ranging from the socio-economic relations of the past societies to the cooking and food storage practices [1]. The various admixtures such as sand, crushed shells, hay or cut straw [2] added to the clay material are important components that change the properties of the ceramic paste. They are therefore informative on the use of the recipient [3]. Hay straw was not often analysed as the organic material mostly burns out during the firing but the morphology of the ceramic pores can give an appreciative clue on the additive organic material (Fig. 1). Depending on the firing conditions, temperature and atmosphere, the remains of organic material can be occasionally found within the ceramic body. The hay voids morphology, volume, and quantification can give information on the firing conditions [4]. It is challenging to distinguish fired organic parts from the air and to quantify them which is why higher quality CT is needed for this exercise than common laboratory micro-CT. This work shows the correlation of the hay residues with the firing conditions in a 3D volume and in a non-destructive manner. 2. Materials and Methods The raw and fired ceramics (Fig. 1) with the hay are prepared and provided by the geological institute from Masaryk University. The X-ray CT measurements are done at CEITEC with micro-CT Heliscan from Thermofisher Scientific. The segmentation is done with VG studio. 3. Results and Conclusion The challenge of this study lies in the contrast between the organic material and the air for proper segmentation and quantification. The Heliscan resolution and enhanced contrast is a step-through for the visualization and quantification of the organic matter in the matrix. The determination of the pores morphology of known material offers the possibility to determine the admixtures used and the firing conditions in original artefacts. 4. Acknowledgements We acknowledge CzechNanoLab Research Infrastructure supported by MEYS CR (LM2018110). Jozef Kaiser gives thanks to the support of the Grant FSI-S-20-6353. 5. References [1]I. S. Zhushchikhovskaia (2012), DOI: 10.2753/AAE1061-1959510103 [2] D. Riegert et al. (2011), DOI: 10.2478/v10172-011-0019-7 [3] A. Hein et al. (2018), DOI: 10.1016/j.prostr.2018.09.031 [4] N. S. Müller et al. (2015), DOI: 10.1016/j.jeurceramsoc.2014.09.025

Thermal-induced changes; Organic temper; Archeological Ceramic; Computed tomography

JAQUES, V.; BLAŽEK, P.; PETŘÍK, J.; SLAVÍČEK, K.; ZIKMUND, T.; KAISER, J.

27. 6. 2022

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https://ictms2022.sciencesconf.org/data/pages/poster_programme_vf2.pdf