| dc.description.abstract | Chemical characterization of archaeological common wares is important in
order to make quantitative explanations about history and trade relations of nations.
Chemistry uses a microscopic point of view by applying spectroscopic methods
rather than macroscopic studies that archaeologists usually deal in the structural
analysis. The present study is done on the common ware samples which were made
of raw clays from Demirci, Sinop, Black Sea Coast of Turkey, because of the
geopolitical importance of this region having trade routes.
Elemental and mineralogical analyses of the clay-originated common ware
samples found in the archaeological excavations and of the clay taken from Demirci
region, which locates at almost 15 km southern of Sinop, were made. While the
elemental compositions of the samples were obtained by the spectroscopic method,
X-Ray Fluorescence (XRF), the mineral structures were investigated by Powder XRay
Diffraction (PXRD) and Fourier Transform Infra Red (FT-IR) spectroscopic method. Furthermore, the characteristic reactions (dehydroxylation, decomposition,
transformation) that the clays experienced between the temperatures 50 and 1000 o
C
were determined by Thermal Gravimetric Analysis (TGA). Characterizations of the
Sinopean samples were made and the similarity and differences between other
samples from different regions were investigated. Besides the provenance
characterization, the distinctions between the production and firing techniques were
observed.
In addition to the experimental studies, chemometric techniques using
statistical methods such as the standard clustering method and principal component
analysis (PCA) was also applied to identify the groupings in the set of samples.
As a result of this study, it is observed that the raw clays and ceramic samples
have minerals of montmorillonite, quartz, feldspars, pyroxene, calcite and hematite at
different amounts. From the mineralogical and elemental data, it is concluded that the
color variations are resulted from the calcium element occurring in pyroxene mineral.
In the light colored samples, amount of this element and mineral is high whereas it is
low in red colored ones.
From the interpretation of elemental data by statistical methods, it is observed
that a classification among the Demirci samples is possible according to the function
of the pottery. In addition, classification among ceramics from two different regions
is possible by the interpretation of chemical analysis, even though the ceramics have
the same morphological properties of the same period. | en_US |
