İstanbul Neolitik Çağ canlılarının nötron aktivasyon analizi ile ıncelenmesi

In the study, the shells of Gastropods, Mytilus galloprovincialis, Acanthocardia spinosa, Ostrea edulis, several fish vertebras as well as a tortoise shell were analyzed by Neutron Activation Analysis. Results were compared to those from the literature to contribute some subjects such as Istanbul's oldest animals lived in Neolithic age by evaluation of the results. Findings were collected from various depths on Marmaray Site from Marmaray-Metro Project Archaeological Excavations at Yenikapı, Istanbul. Neutron Activation Analysis technique was applied by irradiation of samples at the TRIGA Mark II Research Reactor of the Atominstitut of Vienna Technical University. In this frame concentrations of Na, K, Sc, Cr, Fe, Co, Ni, Zn, As, Rb, Sr, Zr, Sb, Cs, Ba, La, Ce, Nd, Sm, Eu, Tb, Yb, Lu, Hf, Ta, W, Th and U elements were determined. The distribution of the elements in the shells was categorized into three groups. Of these, first 7 elements (Na, K, Fe, Co, Cr, Ni, and Zn) were grouped together because of their contribution to living organisms. Their average concentrations changes from 0,243 to 11,33 mg/kg. Second ten elements (Sc, As, Rb, Sr, Zr, Sb, Cs, Ba, Hf, and Ta) are not essential to living organisms, nevertheless may provide additional information regarding e.g. pollution of the sea with further discussion. Their concentrations are between 0,016 and 3,142 mg/kg. The remaining ten elements consists from Lanthanides and Actinides (La, Ce, Nd, Sm, Eu, Tb, Yb, Lu, Th and U) which often called "Rare Earth Elements (REE's)" are the most commonly investigated elements with NAA. Their average concentration varies between 0,078 and 5,523 mg/kg throughout species. The main contribution of Zn and U comes from fish bones and tortoise shell in accordance with the differences in chemical composition between shells and bones of marine animals. The characteristics of the 27 elements were studied separately in samples. It is known that, in mollusk taxonomy, the elements have unique values. In other words, element concentrations in various mollusk shells depend mainly on the taxonomic characteristics of mollusks. In different bionomic environments, various element distributions of the same species are attributed to the different geochemical characters of the each environment. Considering that the organisms are the most active and deterministic factors of the environment, data obtained in this study will serve as a database for future research.