Investigation of ceramic findings from Early Byzantine Period obtained from excavations of Theodosius harbor by nuclear techniques

In present study, 33 ceramic findings dated to Early Byzantine ages excavated by Republic of Turkey Ministry of Transport, Maritime Affairs and Communications, and Istanbul Metropolitan Municipality within "Marmaray and Metro Project" were quantitatively analysed according to inner self-slip and ornaments by means of chemical composition using nuclear techniques. Ceramic findings provided by private permissions from The Ministiry of Culture and Tourism of Turkey General Directorate of The Istanbul Archaeological Museums. In Yenikapı, during the activities, which have turned into the most comprehensive archaeological excavations related to the history of İstanbul, in Yenikapı, where a central station is going to be constructed, between 1 and 6.30 meters below the sea level, the Port of Theodosius, the largest port in the Early Byzantine Period was unearthed. The purpose of this master thesis is to achieve analyzing inner lining, and ornaments of the ceramic finds which is found under the Port of Theodosius from the Early Byzantine period by using nuclear methods to characterize chemical composition, and to classify ceramics according to their origin by using statistical analysis method. By the obtained data, it is aimed to clarify that the materials which are used by the people that living in this area in their daily lives and to clarify the technology used to produce these materials. Chemical composition of the inner self-slip and pigments of ceramic samples were analyzed by instrumental neutron activation analysis (INAA) and energy distributed X-ray flourecence (EDXRF) spectrometer. Information about the ceramic technology of this period is to be achieved. The application of the instrumental neutron activation analysis (INAA) and energy dispersive X-ray flourecence (EDXRF) spectrometer in support of provenance research of archeological ceramics have been largely used over the past few decades. Both techniques are sensitive technique useful for quantitative multi-element analysis of major, minor, and trace elements. Among these, trace elements can be particularly useful to determine provenance of the mineral components in the paste of archaeological ceramics or to distinguish different ceramic groups, better differentiating diverse raw materials. According to results, it was revealed that nearly all Early Byzantine ceramic samples major element composition were %50-70 SiO2, %10-34 Al2O3, %2-6 FeO, %1-5 MgO, %1-5 K2O, %2-20 CaO. Ceramic samples, which have basic element such as K, Mg in chemical composition, classified as basic clay materials. It is known that glazing techniques are used for nearly all Early Byzantine ceramics and non-glazed ceramics were unpopular in Early Byzantine period. The glaze which is used for Byzantine ceramics is leaded-glaze and that glazing material consists of lead-oxide. The lead ratio of ceramics in the elemental composition of glazed surfaces were determined nearly 40 times bigger than the lead ratio of non-glazed surfaces. This result shows that possibility of lead poisoning in this period would be high. The sulphur (S) content which was detected after analysis an indication of the presence of minerals containing limestone and gypsum in the ceramic samples. Having the lower amount of sulphur in the ceramic samples of 31, 32, 33, 38, 40, and 42 as compared to other ceramic samples, it is an indication that the raw material and resource of these ceramic samples (31, 32, 33, 38, 40, and 42) differ from other ceramic samples. The content of calcite (CaCO3) of ceramic samples were different. It was detected that the calsium content in ceramic samples 2, 10, 12, 19, 20 and 24 were quite high. Magnesium compounds are due to presence of in ceramic structures with the formation of limestone and with the effect of the subsequent alteration of dolomite (CaMgCO3) and magnesite (MgCO3). The detected amount of MgO content of ceramics were differ from %1 to %6. This result show that there were different amount of limestone in the structure of ceramics. It can be said that, during this period (Early Byzantine Period), sintering technique that was still in development and still very low sintering temperatures (<700 °C) was common. The composition of inner self-slip and pigments of the study collection ceramic samples were statistically analyzed by clustering methods and identified of similiar characteristic by using Minitab 17.0 statistical program. Cluster analysis or clustering is the task of grouping a set of objects in such a way that objects in the same group (called a cluster) are more similar (in some sense or another) to each other than to those in other groups (clusters). It is a main task of exploratory data mining, and a common technique for statistical data analysis, used in many fields, including machine learning, pattern recognition, image analysis, information retrieval, and bioinformatics. There are numerous ways in which statistical clusters can be formed. Hierarchical clustering is one of the most straightforward methods. In this study, hierarchical method was chosen as clustering method. According to statistical analysis and evaluations, six clusters have identified. It was seen that, two ceramics for Cluster 1 and Cluster 2, twelve ceramics for Cluster 3, four ceramics for Cluster 4, two ceramics for Cluster 5 and five ceramics for Cluster 6 categorized themselves and the relationship for each cluster, amongs other clusters and themselves have been shown. After carefully evaluating results, the highest similarity level was found between Ceramic 31 and Ceramic 33 with the %96 ratio. Moreover, Ceramic 30, Ceramic 35 and Ceramic 40 had a triple connection with the similarity of 92% ratio. Ceramic 2 and Ceramic 20 were remarkable clusters which had %94 ratio of similarity. However, in terms of clustering with the 63% ratio of similarity level and the lowest linkage level were Ceramic 11 and Ceramic 32 consisting of Cluster 5. From the obtained data, raw material compositions and properties, calcination temperature, glazed composition and properties of the ceramic findings were evaluated to clarify the technology and characterizing of the related period.