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    The bituminous mixtures of Kavusan Hoyuk (SE Turkey) from the end of the 3rd millennium (2000 BC) to the Medieval period (AD 14th century): Composition and origin
    (Pergamon-Elsevier Science Ltd, 2013) Connan, J.; Kozbe, G.; Kavak, O.; Zumberge, J.; Imbus, K.
    Bituminous mixtures were observed on potsherds at Kavusan Hoyuk, one of the rescue excavations along the Upper Tigris River in southeastern Turkey. Analysis of 26 samples from six periods spanning from the end of the 3rd millennium BC to the Medieval period (AD 14th century), has shown that bituminous mixtures possess the classical gross composition of most bitumen-bearing mixtures analysed in many archaeological sites of the Near East and the Gulf of Arabia. To search for the geological sources of bitumen, oil seeps, oil stained rocks and crude oils from Turkey and Northern Iraq were analysed as reference using the same geochemical tools: biomarkers and stable isotope composition. The principal conclusion is that the bitumen has been imported from the Eruh outcrop, 120 km east of Kavusan Hoyuk. Additionally, the bitumen from Eruh was imported to Kavusan over a long time period, from the end of the 3rd millennium BC to the AD 14th century. (C) 2012 Elsevier Ltd. All rights reserved.
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    Identification and origin of bitumen in Neolithic artefacts from Demirkoy Hoyuk (8100 BC)
    (Pergamon-Elsevier Science Ltd, 2006) Connan, J.; Kavak, O.; Akin, E.; Yalcin, M. N.; Imbus, K.; Zumberge, J.
    Two ring-like artefacts from the aceramic Neolithic site of Demirkoy Hoyuk in southeastern Turkey were analysed using geochemical techniques in order to determine whether they were prepared using a bitumen amalgam or not. The artefacts, dated 8 100 BC, are early evidence of the innovative use of a petroleum-based material to prepare pieces of ornaments (beads, rings, etc.) for the elite of a Neolithic settlement. In order to trace the source of the presumed bitumen, two oil seeps, Bogazkoy and Yesilli, were sampled. To complete the genetic references, geochemical data on crude oils from the main oil fields from the area were compiled. Basic geochemical data show that bitumen is present in the artefacts. Sterane and terpane patterns, as well as carbon isotopic data on C15+ saturated and C15+ aromatic hydrocarbons, allowed us to conclude that the Demirkoy Hoyuk bitumen and the Bogazkoy oil seep were generated from a Silurian source rock. The detailed geochemical characteristics show, however, that the Demirkoy Hoyuk bitumen does not correlate perfectly with the Bogazkoy oil. This discrepancy suggests several explanations: the real bitumen source may be elsewhere in the vicinity and has not been discovered or was at the Bogazkoy oil seep location but with slightly different properties in Neolithic times, or has disappeared. Another possibility is that the slight molecular differences are due to weathering effects, which affected the pristine bitumen within the archaeological sample. (c) 2006 Elsevier Ltd. All rights reserved.
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    ORGANIC GEOCHEMICAL CHARACTERISTICS OF SIRNAK ASPHALTITES IN SOUTHEAST ANATOLIA, TURKEY
    (Estonian Academy Publishers, 2010) Kavak, O.; Connan, J.; Erik, N. Y.; Yalcin, M. N.
    In this study, the organic geochemical properties of asphaltites in,Sirnak region in Southeast Anatolia are given in detail. Total organic carbon, Rock-Eval pyrolysis, gas chromatography of saturated fractions, gas chromatography-mass spectrometry and stable carbon isotope (delta(13)C in parts per thousand/PDB) analysis were conducted on the,5irnak region asphaltite seams. Some of these analyses were performed for the host rocks as well. It is suggested that a live oil seep occurs within asphaltites, which themselves may be formed in a multiple phase system. The amount of total organic matter in asphaltites is high as would be expected, ranging from 12 to 73%. In contrast, this amount is low in the host rocks (0.6-6.3%). The T(max) values are generally between 428 degrees C and 451 degrees C. The hydrogen index (HI) values vary between 270 and 541 mg HC/g TOC. The hydrogen index values and T(max) of the host rocks are significantly lower. The GC analyses have shown that the saturated fractions of all asphaltite samples were not biodegraded. Consequently, organic geochemical parameters such as Hopane/Hopane+Moretane, T(s)/T(m), 22S/22S+22R and the values of %C(27), %C(28), %C(29) steranes obtained as a result of GC-MS analysis were used for maturity assessments. Although the organic geochemical parameters provided some data for the origin and placing mechanism, it is concluded that they are not sufficient for an overall conclusion, especially concerning placing mechanism. Therefore, new studies particularly on local and regional geological aspects need to be undertaken.