Investigations of the Neolithic potteries of 6th millennium BC from Goytepe-Azerbaijan by vibrational spectroscopy and chemometric techniques

Abstract

This article presents the results of the vibrational spectroscopic and chemometric analyses of Neolithic pottery remains excavated in Goytepe (Azerbaijan), a typical Shomutepe-Shulaveri culture settlement. Fifty-five pottery fragments, that were unearthed in the excavations of Goytepe during the 2009-2013 years, were investigated using Fourier Transform Infrared (FTIR) and micro-Raman spectroscopy. X-Ray Diffraction (XRD) was used as a complementary technique. The firing-temperature and -conditions were inferred from the mineral phases obtained from the vibrational spectra of the samples and were estimated to be between 600 degrees C and 750 degrees C in oxidizing atmosphere. As chemometrics, Principal Component Analysis (PCA) followed by Linear Discriminant Analysis (LDA), were applied to the FTIR spectral data, in order to examine the possible classification of those findings, and to extract the most discriminant features. Pottery fragments were identified and characterized, depending on the excavation levels, by PCA-LDA analysis.