Devonian in Turkey - a review

The Devonian Period is represented in Turkey by almost complete non-metamorphic sections of more than 1000 meters, which exhibit varying lithofacial associations. They are parts of thick Paleozoic sedimentary successions in the Pontides, Taurides and Arabian Plate. The tectonic setting and the paleogeographical origin of these terranes is different. Therefore, the litho- and biostratigraphy and facies characteristics of these Devonian successions would enable a comparison and a paleogeographical assignment of these tectono-stratigraphic units. Devonian successions of the Arabian Plate and of the Taurides are represented by facies associations ranging from tidal flat to a deep shelf. Whereas, those of the Istanbul and Camdag-Zonguldak areas in the Pontides by a deepening upward sequence front a shallow shelf into a basin and a stable shelf, respectively. The Devonian of the Arabian Plate and the Taurides can surely be assigned to Gondwana. A Peri-Gondwanan (Avalonian) setting is suggested for the paleogeographic position of the Devonian of the Pontides

New evidence for a mixed inorganic and organic origin of the Olympic Chimaera fire (Turkey): a large onshore seepage of abiogenic gas

The Chimaera gas seep, near Antalya (SW Turkey), has been continuously active for thousands of years and it is known to be the source of the first Olympic fire in the Hellenistic period. New and thorough molecular and isotopic analyses including methane (approximately 87% v/v; delta C-13(1) from -7.9 parts per thousand to -12.3 parts per thousand; delta D-13(1) from -119 parts per thousand to -124 parts per thousand), light alkanes (C-2 + C-3 + C-4 + C-5 = 0.5%; C6+: 0.07%; delta C-13(2) from -24.2 parts per thousand to -26.5 parts per thousand; delta C-13(3) from -25.5 parts per thousand to -27 parts per thousand), hydrogen (7.5-11%), carbon dioxide (0.01-0.07%; delta C-13(CO2): -15 parts per thousand), helium (approximately 80 ppmv; R/Ra: 0.41) and nitrogen (2-4.9%; delta N-15 from -2 parts per thousand to -2.8 parts per thousand) converge to indicate that the seep releases a mixture of organic thermogenic gas, related to mature type III kerogen occurring in Palaeozoic and Mesozoic organic-rich sedimentary rocks, and abiogenic gas produced by low-temperature serpentinization in the Tekirova ophiolitic unit. Methane is not related to mantle or magma degassing. The abiogenic fraction accounts for about half of the total gas released, which is estimated to be well beyond 50 ton year(-1). Ophiolites and limestones are in contact along a tectonic dislocation leading to gas mixing and migration to the Earth's surface. Chimaera represents the biggest emission of abiogenic methane on land discovered so far. Deep and pressurized gas accumulations are necessary to sustain the Chimaera gas flow for thousands of years and are likely to have been charged by an active inorganic source

The Permian Kas Formation of SE Turkey-palynological correlation with strata from Saudi Arabia and Oman

The Kas Formation in SE Turkey was deposited as part of the Permian sequence on the northern margin of the Arabian Plate. Its stratigraphic relationship to time-equivalent strata of the Arabian Plate was mentioned briefly in previous studies, but has not been elaborated and illustrated in detail. This biostratigraphic review of existing palaeontological data has improved the accuracy of age interpretation for the Kas Formation, and the relationship of its excellent palynological record to the international Permian chronostratigraphic units. As a result, this study has identified a number of key palynological species from the Kas Formation, which occur as well as in the 'Basal Khuff Clastics' of Saudi Arabia and in the 'Khuff transition section' of Oman. All these units have approximately the same age: Wordian to early Capitanian, based on 'age control' provided by Foraminifera. This study also demonstrates that, by using key palynological taxa, correlation of strata would be possible across the entire Arabian Plate in this narrow time range. Hence, the 'Oman and Saudi Arabia Palynological Zone 6' (OSPZ6) is applicable throughout the Arabian Plate area, including the northern regions of SE Turkey and Iraq. Copyright (C) 2011 John Wiley & Sons, Ltd

Experimental and theoretical studies of (E)-1-(2-hydroxybenzylideneamino)-5-(4-methoxybenzoyl)-4-(4-methoxyphenyl)pyrimidin-2(1H)-one (vol 141, pg 307, 2015)

Ozdemir, Namik/0000-0003-3371-9874; ceylan, umit/0000-0002-1461-9889WOS: 000356104100041

Experimental and theoretical studies of (E)-2-(2-hydroxystyryl)-6-(4-methoxybenzoyl)-5-(4-methoxyphenyl)-1,2,4-triazin-3(2H)-one

Ozdemir, Namik/0000-0003-3371-9874; ceylan, umit/0000-0003-2888-2378; ceylan, umit/0000-0002-1461-9889WOS: 000352925500041PubMed: 25704130Crystal structure of the title compound, C26H21N3O5, has been synthesized and characterized by Fr-IR, H-1 NMR, C-13 NMR and X-ray single crystal determination. The molecular geometry was also calculated by using Gaussian 03 software and structure was optimized by using HF and DFT/B3LYP method with the 6-31G(d) basis sets in ground state. The comparison of the theoretical and experimental geometries of the title compound indicated that the X-ray parameters agree with the theoretically obtained values. It was seen that R-2 value changes from 0.015 to 0.021 angstrom for bond length and angle. The calculated vibrational frequencies are also in good agreement with the experimental results. The H-1 and C-13 NMR chemical shifts values of (E)-2-(2-hydroxystyryl)-6-(4-methoxybenzoyl)-5-(4-methoxyphenyl)-1,2,4-triazin-3(2H)-one molecule have been calculated by the GIAO method. Besides, molecular electrostatic potential maps (MEP), Mulliken charges and Nonlinear Optical effects (NLO) analysis of the compound have been calculated by the HF and B3LYP/6-31G(d) methods. (C) 2015 Elsevier B.V. All rights reserved

ORGANIC GEOCHEMICAL CHARACTERISTICS OF SIRNAK ASPHALTITES IN SOUTHEAST ANATOLIA, TURKEY

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

Isotopic and molecular composition of coal-bed gas in the Amasra region (Zonguldak Basin - western Black Sea)

Previous studies on the coal-bed methane potential of the Zonguldak basin have indicated that the gases are thermogenic and sourced by the coal-bearing Carboniferous units. In this earlier work, the origin of coal-bed gas was only defined according to the molecular composition of gases and to organic geochemical properties of the respective source rocks, since data on isotopic composition of gases were not available. Furthermore, in the western Black Sea region there also exist other source rocks, which may have contributed to the coal-bed gas accumulations. The aim of this study is to determine the origin of coal-bed gas and to try a gas-source rock correlation. For this purpose, the molecular and isotopic compositions of 13 headspace gases from coals and adjacent sediments of two wells in the Amasra region have been analyzed. Total organic carbon (TOC) measurements and Rock-Eval pyrolysis were performed in order to characterize the respective source rocks. Coals and sediments are bearing humic type organic matter, which have hydrogen indices (HI) of up to 300 mgHC/gTOC, indicating a certain content of liptinitic material. The stable carbon isotope ratios (delta(13)C) of the kerogen vary from -23.1 to -27.7parts per thousand. Air-free calculated gases contain hydrocarbons up to C-5, carbon dioxide ( 98%). The stable carbon isotope ratios of methane, ethane and propane are defined as delta(13)C(1): -51.1 to -48.3parts per thousand, delta(13)C(2): -37.9 to -25.3parts per thousand, delta(13)C(3): -26.0 to -19.2parts per thousand, respectively. The deltaD(1) values of methane range from -190 to -178parts per thousand. According to its isotopic composition, methane is a mixture, partly generated bacterially, partly thermogenic. Molecular and isotopic composition of the gases and organic geochemical properties of possible source rocks indicate that the thermogenic gas generation took place in coals and organic rich shales of the Westphalian-A Kozlu formation. The bacterial input can be related to a primary bacterial methane generation during Carboniferous and/or to a recent secondary bacterial methane generation. However, some peculiarities of respective isotope values of headspace gases can also be related to the desorption process, which took place by sampling. (C) 2002 Elsevier Science Ltd. All rights reserved