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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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    Geochemical Methods to Investigate the Hydrocarbon Seepage Samples in Adiyaman a Southeastern Province of Turkey
    (Springer International Publishing Ag, 2015) Onen, K.; Yilmaz, M. A.; Dicle, Y.; Kavak, O.; Temel, H.
    The southeastern part of Turkey is quite rich, fertile and mature in terms of hydrocarbon seepages. While the use of the related sources meet the energy demand, it damages the environment and human health. In this study, several geochemical methods were applied to analyze the hydrocarbon sepage samples obtained from seven towns in the province of Adiyaman where is very close to the oil production areas and located in the Southeastern part of Turkey. First of all, Total Organic Carbon (TOC), Rock Evil Paralysis, Gas Chromatography (GC) and Gas Chromatography Mass Spectrometry analyses (GC - MS) were performed for the samples in question. In the light of these results, oil/bitumen mechanisms, source rock correlations, formation and migration mechanisms of the related geological environments were found. Then, Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) analysis of Fe, Al, Mn, Mn, Zn, B, Pb, Ni, Cu metals were performed. Chemical and mineralogical features of the samples were investigated by IR and combined with ESR spectra. The samples display typical ESR spectra of Mn+2 ions hyperfine sextet whose last line was used to check the stones homogenity with respect to manganase content. In this study, heavy metal pollution and hydrocarbon compounds were determined to damage the environment and several suggestions were made to overcome the pollution and to enhance the productivity
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    The geochronology and origin of mantle sources for late cenozoic intraplate volcanism in the frontal part of the Arabian plate in the Karacadag neovolcanic area of Turkey. Part 1. The results of isotope-geochronological studies
    (Pleiades Publishing Inc, 2012) Keskin, M.; Chugaev, A. V.; Lebedev, V. A.; Sharkov, E. V.; Oyan, V.; Kavak, O.
    This paper considers results from isotope-geochronological (K-Ar) studies of the products of Neogene-Quaternary volcanism in the Karacadag area, which is situated within the northern frontal part of the Arabian plate. It was found that magmatic activity has been evolving at this location for at least the last 11-10 Myr and was distinctly discrete in character. Three stages of volcanism have been identified: (I) Early or Miocene, similar to 11-6.7 Ma; (II) Middle or Pliocene-Early Quaternary, 4-1 Ma; and (III) Late or Late Quaternary, 0.4-0.1 Ma. The most recent manifestations of magmatic activity in the region date back to about 100000 years ago. An analysis of the spatial distribution of volcanic centers of different ages in the Karacadag neovolcanic area shows that the magmatism of that region involved a lateral migration of activity from northwest to southeast along a major regional tectonic fault. The migration was caused by the movement of local tension zones where the lithosphere was thinner and deep-seated mantle magmas were ascending.
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    The geochronology and origin of mantle sources for late cenozoic intraplate volcanism in the frontal part of the Arabian plate in the Karacadag neovolcanic area of Turkey. Part 2. The results of geochemical and isotope (Sr-Nd-Pb) studies
    (Pleiades Publishing Inc, 2012) Keskin, M.; Chugaev, A. V.; Lebedev, V. A.; Sharkov, E. V.; Oyan, V.; Kavak, O.
    A geochemical and isotope-geochemical (Sr-Nd-Pb) study has been carried out for the Karacadag neovolcanic area, which is situated within the frontal part of the Arabian plate. The obtained data and the results of petrological modeling show that the petrogenesis of parental magmas in the Karacadag neovolcanic area involved two compositionally different mantle sources; one consisted of garnet-bearing peridotites of the asthenosphere mantle and the other was spinel-bearing peridotites of the enriched subcontinental lithosphere mantle. During early stages in the evolution of the magmatic system, deep-seated asthenospheric magmas were ascending to the surface while intensively interacting with the melts that had been generated at upper mantle depths. The interaction gradually diminished, so that the later effusive rocks mostly have compositions that are similar to those of the primitive asthenospheric magmas. It is shown that a significant (up to 17-18 wt % of the mantle melt) assimilation of crustal material could take place only during the initial phases of the magmatism. Periodic replenishment of the magma chambers by primitive magmas, which resulted in an observable high degree of homogeneity in the composition of young effusive rocks, was also of importance in the petrogenesis of lavas during the evolution of volcanic activity.
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    GEOLOGICAL AND ARCHITECTURAL INVESTIGATION OF REUSED ROCK COLUMNS IN THE GREAT MOSQUE IN DIYARBAKIR OLD CITY (TURKEY)
    (Univ Agean, Dept Mediterranean Stud, 2011) Kavak, O.; Dalkilic, N.; Toprak, V.
    Cylindrical rock columns in the Great Mosque in Diyarbakir Old City are investigated for their lithology and architecture. The columns belong to four different rock types, namely pre-Tertiary meta-ophiolites, Eocene limestones, Miocene limestones and Plio-Quaternary basalts. The columns from the first three lithologies are reused during the construction and/or renovation of the Great Mosque. Thin sections prepared from 18 columns of this building confirm they are derived from the rocks exposed in the region. The reuse of the columns is approved by inconsistent column lengths, multi-segment column shafts, lithologically mixed columns and presence of thin wedges at the bottom of column bases. These columns are not used to support the main body but rather either for partial support or only for decorative reasons.
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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.