Yenikapı Kazı Buluntularındaki Neolitik Ve Erken Bizans Dönemi İnsan Kemiklerinin X-ışını Floresans Yöntemi İle Karakterizasyonu

Abstract

2004 yılında başlayan Yenikapı Marmaray metro inşaatı sırasında günümüz deniz seviyesinden 13 metre aşağıya kadar olan 52 bin metrekarelik alanda İstanbul'un tarihini değiştirecek Neolitik Çağa ve Bizans Dönemine ait arkeolojik buluntulara rastlanmıştır. 8500 yıldır uykuya yatan İstanbul tarihini uyandırıp gün ışığına çıkaran bu buluntular üzerinde yapılacak ilgili çalışmalar, İstanbul'un geçmişini yeniden yazmaya yardımcı olacaktır. Bu çalışmada, Yenikapı metro Marmaray kazıları sırasında çıkarılan Neolitik ve Bizans Dönemine ait arkeolojik insan kemikleri incelenmiştir. X-ışını floresans yöntemi ile kemiklerdeki Al, Ba, Ca, Cu, Fe, K, Mg, Mn, P, Pb, S, Se, Si, Sr, V, Zn elementleri analizlenmiştir. Sonuçlar, günümüz insan kemikleri ile kıyaslanarak Neolitik ve Bizans dönemlerine ait yeme-içme alışkanlıkları, olası hastalıkları, kullandıkları teknolojiler ve günlük yaşantıları ile ilgili dönem karakterizasyonu yapılmıştır. Elde edilen sonuçlara göre, Ca/P oranının yüksek olması sebebiyle kemiklerdeki diyajenize sürecin ileri düzeyde olduğu tahmin edilmektedir. Bitkisel kaynaklı elementler olan Ba, Mn ve Sr ve hayvansal kaynaklı elementler olan V, Cu ve Zn konsantrasyonlarının değişimleri günümüz insan kemiğindeki element konsantrasyonları ile normalize edilmiş ve paralel koordinatlar grafiği ile değerlendirilmiştir. Neolitik dönemden Bizans dönemine geçiş döneminde kemiklerde Ba, Mn ve V miktarının azaldığı, Sr miktarının çok az arttığı ve Cu ve Zn miktarının daha çok arttığı görülmüştür. Neolitik Çağ, Bizans Dönemi ve günümüz insan kemiklerinde Pb değerleri arasında Bizans dönemine ait kemiklerde 100 kat fazla Pb miktarı tespit edilmiştir. Neolitik ve Bizans dönemi insanları günümüz insan kemiği ile normalize edildiğinde Al, Fe, K, Mg, S ve Si miktarlarında düşüş görülmektedir. Ca ve P'un yaklaşık olarak aynı kaldığı ve Se miktarının ise arttığı görülmüştür. Bu elementlerdeki değişimlerin beslenme alışkanlıkları, çeşitli hastalıklar ve kullanılan teknolojilerle açıklanabilmesinin yanında, dönem arkeojeolojisi hakkında bilgi vermektedir. Bu çalışma, Neolitik Çağa ve Bizans Dönemine ait arkeolojik kemik buluntular hakkında merak uyandıran soruların cevaplandırılması kapsamında Yenikapı Marmaray Metro Projeleri Arkeolojik Kazılarının değerlendirilmesi için gerek duyulan laboratuvar incelemeleri ile desteklenmesi ihtiyacını karşılamıştır. Bu nedenle, sonuçlar bu kapsamda yapılacak diğer arkeolojik çalışmalar için veritabanı oluşturacağından önem arz etmektedir.

Istanbul is believed that it has been always the center of life during known the history and its history go back to the mythological ages. However, known history about Istanbul were limited to BC 7 centuries based on ancient findings. In order to find a solution for Istanbul traffic jam, the subway and tunnel project, Marmaray, construction were started in 2004. During the construction excavation of Yenikapı station, some archaeological remains of belonging to Ottoman were found. By decreasing in altitude, discovering of new archeological remains continued and Subway and Marmaray tunnel project construction were converted into archeological excavation and 58000 m2 areas of Yenikapı was uncovered and archeological findings belonging to layers of Neolithic, Roman, Early Byzantine, Byzantine and Ottoman were found at the end of excavation. This excavation is seen as revolution for history of Istanbul because it reflects the cultural history of the city and its changing. Moreover, it shows the importance like a library considering both city and world heritage. Archeological findings especially bones are key of the ancient human lifestyle. In this study, human bones belonging to Yenikapı Marmaray and subway excavation were analyzed and dietary habits, possible illness, physical properties, technologies and daily lives of human from Neolithic and Byzantine period were characterized by comparing these results with modern human bones. Part of obtained samples are dated BC 6500 Neolithic Age. Neolithic age is seen as a first step of civilization of human, so this age is seen as a one of the most important age among the whole history of humankind because human discovered the fire, started to agriculture, domesticated animals for the first time. Therefore, they began to control the nature. In Yenikapı excavation, four grave belonging to the Neolithic age has been discovered from the sea level between 6-8 m. The other part of investigated samples are dated (330-726) for Early Byzantine Age and were found in below between 1 and 6,30 m from sea level. There are 2 grave types for Early Byzantine age. First type, generally around the church, made of soil, tile and brick and there were found 23 graves. The second type is called hipoje graves like grave room thought to belong to royal people. However, there was not informed about the types of the obtained samples in this study. Samples were milled freezer mill but the some samples could not be milled because of hardness and vibrating ball mill was used for mill the Neolithic and Early Byzantine samples. After samples became powder, pelleting procedure was applied. X-ray florescence analysis is one of the most used elemental analysis methods in metallurgy, criminal science, polymers, archeology, electronic, environment, geology and mining. Pelletized samples were analysed by this nuclear analytical method. Regarding the determined Al, Ba, Ca, Cu, Fe, K, Mg, Mn, P, Pb, S, Se, Si, Sr, V and Zn concentrations in bones the following considerations were examined: • Fingerprints of Neolithic and Early Byzantine bones According to chemical fingerprints, it is determined that elements of Al, Ba, Fe, K, Mg, Mn, S, Si, V are decreasing, whereas elements of Cu, Pb, Se, Sr ve Zn is increasing from Neolithic age to Early Byzantine period. • Change of Ca/P ratio Several researches agree in the using of Ca/P ratio to get information about evaluation of bone integrity and diagenesis process. Glancing at the results, Ca/P ratio is changing from 10,9 to 13,2 in investigated samples. Considering that modern human bones have average 2,25 Ca/P ratio, Ca/P ratio in modern human bones is highly low. Therefore, it is predicted that either the bones become diagenesis or bone maturity in ancient times is very good. • Change of Sr/Ba ratio According to the information that bone and dietary habits showed a relation for societies which feeding with seafood it is determined that people of Early Byzantine period (have high Sr, low Ba in bones) have marine-based feeding instead of terrestrial, plant-based feeding. • Change of Sr/Zn ratio The Sr/Zn ratio in bones can give information whether a society is feeding with plant-based or animal-based. According to average Sr/Zn ratio results from Early Byzantine period and Neolithic age (the Sr/Zn ratio is 8,0 in Neolithic age and 5,3 in Early Byzantine period) it can be commented that animal-based feeding in Early Byzantine is more than one in Neolithic periode. • Change of Mn, Sr, Ba and V, Cu and Zn concentrations Mn, Sr and Ba are the plant-based elements and V, Cu and Zn are animal-based elements. Elementel concentrations in this study was normalized by Ca concentration in modern human bones, the ratio about plant-based to animal-based in Neolithic age is 141/2. This shows that Neolithic human mainly fed with plan-based foods. Moreover, the ratio about plant-based to animal-based in Early Byzantine age is 2. This result shows that plant-based feeding is sharply decreasing with respect to Neolithic age. From the same results, compared the plant-based feeding in both period, the ratio of plant-based elements accumulating in Neolithic bone to that in Early Byzantine Age is 11,5; however, the ratio of animal-based elements accumulating in Neolithic bone to that in Early Byzantine Age is 0,2. As a result, people in Neolithic age fed with plant-based food, whereas, the people in Early Byzantine period were made quick and a sharp transition to the consumption of animal origin. It is known that people in Neolithic age started the agriculture activities and in the light of this information, getting results and comments have a coherent and make a sense. • The importance of lead concentration in Bones It is predicted that Romans produced 36% of lead of during ancient times and roman times and also predicted that annual produced lead was more than 100000 tons. This study also confirms the rising of lead in Early Byzantine Age with respect to Neolithic and modern times. The possibility of existence of lead in using ceramic both construction material and the coating material and also construction of the water pipe by lead from history knowledge can explain the rising 100 times from Neolithic to Early Byzantine period. • The importance of Al, Cu, K, Mg, Si, Sr and Zn concentrations in bones It is predicted that Neural disorders such as Alzheimer and Parkinson, bone softening and anemic might be observed because of the high level of Al in Neolithic bones. It is also predicted that the excess of Al in Early Byzantine bone results from ceramics whose dyes had been fixed by using Al. It is thought that the handicaps of rigidity in Early Byzantine bone might be result from the excess of Ca during milling the bones. However, the results of Ca level in Neolithic or Early Byzantine have not a significant difference. Now, this handicap of rigidity in Early Byzantine bones is predicted as the excess of lead. It is known that the deprived of Cu causes the Alzheimer, osteoporosis and some heart problems. Besides this, it is known that copper causes to raise the consumption of Zn and comparison of the Zn level results in Early Byzantine, Neolithic age and modern human confirm this information. K analytical results for Neolithic age are concluded the abnormalities of bones and existence of bones based on the lack of K. Mg analyzes results of Early Byzantine period are concluded that Early Byzantine people might have major depression, mental disorders, low IQ level and addiction based on the lack of Mg. Since the Si is soil origin element, the deprived of Si in Early Byzantine, bone can be commented either people did not use pot anymore in Early Byzantine age or the amount of Si in soil was highly low. The reason of increasing of Sr in Early Byzantine can come from the using of carbonate-rich soil besides the plant-rich diet. Additional studies will enlightened the reason increasing of Sr in Early Byzantine properly. This study met the requirements of need for the evaluation of the intriguing questions to be answered about the archaeological finds from the Neolithic and Byzantine bones from Yenikapı Marmaray Metro Project by supporting laboratory inspection of bones. Hence, it can be said that the results are important for establishing a database for further arkeologic studies.