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Paleozoic of Northern Gondwana and Its Petroleum Potential A Field Workshop
- Conference date: 09 Sep 2012 - 14 Sep 2012
- Location: Kayseri, Turkey
- Published: 09 September 2012
44 results
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An Introduction To The Paleozoic Of Anatolia With A NW Gondwanan Perspective
Authors M.C. Göncüoğlu and Middle East Technical UniversityThe earliest attempts to recognize the Paleozoic rocks in Turkey in a more or less systematic approach and correlate them with those in Europe dates back to the second half of the 19. Century, where a number of natural scientists reported in their classical work also the stratigraphy and fossil findings in different Paleozoic successions in Turkey (e.g. Tchihatcheff, 1864; de Verneuil, 1869). The interest of the international geological community grew with the building of the Anatolian and later the Bagdat railways and the “discovery” of the Kirkuk (Musul) oil fields in northern Iraq during the end of the 19. and early 20. Century, where a number of studies on the Paleozoic of Turkey were published (e.g. Frech, 1916; Penck, 1919). The establishment of the Mineral Research and Exploration Institute of Turkey (MTA) followed by the Turkish Petroleum Corporation (TPAO) resulted in systematic mapping of Paleozoic in Turkey, pioneered by a small number of geologists (e.g. Tolun and Ternek, 1952; Dean 1961 to 2006, Ketin, 1966, Kaya, 1973). The litho- and biostratigraphic information obtained between 1950 and 1990 was discussed during a field-meeting of IGCP 256 (Paleozoic of NW Gondwana) in 1995, organized again by the Turkish Association of Petroleum Geologists (TPJD) and published in a special issue of the Association (Göncüo¤lu & Derman, 1996). Following the Iraq War in 2003, the interest of the petroleum companies on the geology of the Northern Mesopotamia made another peak. A number of new research and exploration projects were started also in southern Turkey and a number of detailed studies with new data and models were put forward. To discuss them and record the state-of –art knowledge, TPJD organized this second field-meeting to one of the best preserved Paleozoic sections in the Eastern Mediterranean.
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Silurian-Devonian Boundary In Se Anatolia (3): An Organic-Geochemical Assignment For Positioning Of The Boundary At The Hazro Area
Authors U. Mann, N. Bozdoğan, C. Soylu and M.N. YalçinIn the Hazro area of the Turkish border fold zone in SE Anatolia (Fig. 1), the exact position of the Silurian-Devonian (S-D) boundary is still under debate. Biostratigraphic approaches failed up to now (compare Luppold et al., 2012, this meeting: Silurian-Devonian Boundary 2) due to several missing index fossils (e.g. graptolites), revision of index fossils (conodonts) and a partly incomplete distribution of palynomorphs (e.g. chitinozoans and acritarchs). According to the geological information from this area near the north rim of the Arabian plate, the SD boundary should be positioned within the local Upper Dadas Fm. which represents a subunit of the Silurian to Devonian Diyarbarkır Group (Bozdoğan et al, 1987; Fontaine et al., 1980). Based on Acritarch assemblages, the Dadas Fm. is of Wenlockian to Lochkovian age (Bozdoğan and Ertuğ, 1997).
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The Upper Paleozoic Coral Fauna From Southern Turkey And Adjacent Area, And Paleobiogeography Of The Rugose Coral Kueichouphyllum
By I. NiikawaThere are only few studies on fossil-bearing deposits from the Upper Paleozoic in the Middle and Near East. Among these, studies of coral-bearing formations are known from southern Turkey, Armenia, and from north and central Iran. These are correlated with the Carboniferous and Permian strata by bryozoans and corals. Particularly, these areas except central Iran are characterized by yielding the very large rugose coral Kueichouphyllum. In this meeting, an outline of the Upper Paleozoic bearing corals, especially Kueichouphyllum, from the Middle and Near East and their paleobiogeography are reported.
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Palaeoecology And Palaeogeography Of Ostracods From The Devonian Of Halevıkdere (Eastern Taurides, Turkey)
Authors A. Nazik, M.N. Yalçin, V. Wilde, A. Wehrmann, I. Yilmaz, E. Schindler, H. Kozlu and N. BozdoğanDevonian rocks in the Eastern Taurides are represented by the Ayıtepesi, Şafaktepe and Gümüflali formations. These lithostratigraphic units have been investigated along the measured Halevikdere Section (Sarız region, Eastern Taurides, Turkey). The Ayıtepesi Formation has a thickness of 425 m and is built up by quartzitic, cross-bedded sandstones, well bedded dolomitic layers and some shaly intervals in the Halevikdere Section (Wehrmann et al. 2010). The Şafaktepe Formation is represented by a limestone-dominated facies in the middle part of the section which is highly affected by tectonics. The Gümüşali Formation consists of limestones, shales and siltstones.
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Devonian Conodonts From The Geyıkdağ Unit In The Eastern Taurides (Southern Turkey): Biostratigraphical Implications
Authors D.G. Saydam-Demiray, K. Weddige, E. Schindler, İ. Yilmaz, A. Wehrmann, V. Wilde and M.N. YalçinDevonian rocks are widely exposed in the Taurides of Southern Turkey. In this paper, two sections in the Feke- Saimbeyli-Adana (Kocadere section) and Sarız- Kayseri (Halevikdere section) were measured (Fig 1).
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Early Carboniferous ‘Non Paleozoic-Type’ Monotaxic Shell Beds From The Northern Arabian Plate (Hakkariçukurca Area, Se Turkey): A New Gondwanian Occurrence
More Less‘Paleozoic-type’ shell beds are accumulations dominated by typical members of Paleozoic fauna, such as articulate brachiopods, bryozoans, crinoids, and ostracodes. Articulate brachiopods are the major component of the Paleozoic fauna, and are the dominant members of many shallow-water marine communities (Li and Droser, 1999; Waisfeld et al. 1999; Gourvennec and Hoşgör, 2012). On the other hand, Early Carboniferous shell beds, including bivalve-only and bivalve-dominated beds are very common in the southern Anatolia, Hakkari-Çukurca region (Fig. 1). Bivalve-rich accumulations provide insight into the role of shell composition and taphonomic resilience in the formation of the typical monataxic shell bed types. In the light of the numerous studies from all aquatic ecosystems, bivalves have been used to reconstruct ancient paleoenvironments from Carboniferous strata from Avalonian or Perigondwanan terranes and Gondwana, encompassing marine shelf through to the nonmarine, coal-bearing strata (Okan and Hoşgör, 2007; Hoşgör et al. 2012). Okan and Hoşgör (2007) and Hoşgör et al. (2012) provided a comprehensive summary of Early Carboniferous bivalve paleoecology directly related to the depositional environments. The purpose of this study is to examine the paleontologic, stratigraphic and sedimentologic aspects of such unique accumulations in order to better understand the characteristics of ‘non Paleozoic-Type’ myalinid bivalv shell beds. Fossil deposits were described considering stratigraphic, sedimentologic, taphonomic and palaeoecologic attributes sensu by Kidwell and Holland (1991). Taphonomic features were observed in fossil fragments larger than 5 mm.
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Comparative Analysis Of The Paleozoic Petroleum Systems Of Northern Gondwana With Special Focus On The Silurian “Hot Shales”
More LessThe core-Gondwana continent has undergone a series of tectonic episodes, that influenced the distribution of Paleozoic source rocks and impacted their thickness, petrophysical properties, maturity, thermal and subsidence histories and effectiveness of their associated petroleum systems. Key amongst them are the Pan-African Orogeny and Arabian Plate accretion (850-520 Ma), where the resulting structural fabric has influenced the deposition of later Paleozoic source rocks, and impacted the maturity of Infracambrian sources. Secondly, the mid Carboniferous structural event (Hercynian) which is a major influence the formation of traps and the timing of charge.
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The Unayzah Reservoir (Permo-Carboniferous And Permian) Of Saudi Arabia, A Typical Example For A Large-Scale Reservoir Heterogeneity
By M. ŞenalpIn 1987, exploration started in Central Saudi Arabia shortly after the government directive enlarged Saudi Aramco's exploration activities outside the Retained Areas in Eastern Saudi Arabia. In June 1989, the first oil (Arabian superlight), condensate and gas discovery were made in the continental red bed sandstones of the Early- Middle Permian (Kungurian to Wordian from 275.6 to Ma 265.8 Ma) Unayzah Formation at the Hawtah Field, south of Riyadh. The Hawtah discovery provided a clear evidence for a significant hydrocarbon potential in the Paleozoic successions. Since then, Saudi Aramco has made several new oil and gas discoveries in the Khuff carbonates, Unayzah and Jauf sandstones, both in central and eastern Arabia. Intensive drilling that resulted from these discoveries has provided an immense wealth of new subsurface lithological and palynological data to establish the stratigraphy and sedimentology of the entire Paleozoic succession.
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Petroleum Source Rock Characteristics Of The Dadafi Formation In The Hazro Area (Se Turkey)
Authors C. Soylu, U. Mann and N. BozdoğanAt the northern margin of the Arabian Plate, a big WNWESE trending anticline, the so-called Hazro Uplift (Figure 1), was formed by Cretaceous and Miocene tectonics. Silurian and Devonian deposits, which are overlain by Permian and Mesozoic units are present at the core of this anticline. These deposits, named as "Diyarbakır Group", consist of the Dadaş (Silurian-Lower Devonian), Hazro (Lower Devonian) and the Kayayolu Formations (Middle-Upper Devonian) (Figure 2). As solely Upper Silurian-Lower Devonian deposits outcrop in the Hazro anticline area, both the lowermost part of Dadas formation (Dadas I member) and the Middle-Upper of the Devonian Kayayolu formation can only be studied by information from deep boreholes.
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Source Rock Potential Of Paleozoic Units In The Central And Eastern Taurides, Southern Turkey
Authors H. İ. İlleez, T. Tekin, H. Kozlu, M. A. Gül, N. Şahin, Y.H. İztan, H. Alkan and Y. GünayGeographically the Central Taurides are defined as the area between the Kırkkavak and Ecemiş faults, whereas the Eastern Taurides are defined as the area between the Ecemiş and Eastern Anatolian faults at the southern part of Turkey. As it was presented by Özgül, 1997, Taurides are divided into several tectonostratigraphical units on the basis of stratigraphical, structural and tectonic features. Of these, Aladağ unit is comprising the Devonian- Upper Cretaceous clastics and carbonates; whereas, the Geyikdağı unit consists of Cambrian to Upper Lutetian clastics and carbonates. Paleozoic sections of these units have been focused on as a result of their source rock potentials (Table 1).
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Paleozoic Petroleum Geology And New Oil Field Discoveries In Area-147/3-4, Murzuq Basin In Libya
Authors A. Sayili, Research Center, A. Tandircioğlu, R. Ö. Temel, H. Can and E. YilmazLarge volumes of oil and gas have been generated and trapped within Paleozoic sections in western Libya, Tunisia and Algeria. The Ghadamis and Murzuq Basins, located in the western half of Libya, are the most attractive oil and gas exploration areas for the last decades due to the increasing number of new oil discoveries. The lower part of Silurian Tanezzuft Formation, so called “Hot Shale”, is the major source rock of northwestern African oil and gas fields due to high organic matter content. The Late Ordovician glacial events played a major role in the development of paleo-highs and lows that controlled source rock and reservoir rock distribution. Two major migration systems can be observed in the Murzuq Basin: a fault related vertical oil migration to Devonian reservoirs and combined lateral and vertical oil migration into older, i.e., Cambro-Ordovician, reservoirs and traps. Turkish Petroleum Overseas Company (TPOC), a subsidiary of Türkiye Petrolleri Anonim Ortaklığı (TPAO), tested 11 prospects and discovered 7 oil fields in Area-147/3-4 in the Murzuq Basin. Proven hydrocarbon distribution in the Murzuq Basin reflects the interaction of several factors such as regional structural evolution, source rock quality, distribution and maturity, trap geometry and age, and reservoir quality both in terms of facies variations and diagenetic changes. Migration pathways are controlled by adjacent reservoir facies variations, the fault system distribution, trap type configurations, and the Tanezzuft Shale seal efficiency. The Early Devonian erosion mostly eroded Silurian top seal towards the Gargaf uplift in the northwestern edge of the Murzuq Basin.
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Structural Units Of The Eastern Taurides
Authors M.C. Göncüoğlu, N. Şahin and Middle East Technical UniversityThe Taurus Belt is geographically subdivided into three portions by two N-S oriented major faults (Figure 1) The Eastern Taurus region is bordered in the east by the Munzur Mountains and in the west by the Ecemifl fault.
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Quantitative Basin Analysis Of Libya Murzuq Basin, Area 147 - Block 3 And 4
Authors Ö. Aksu, Exploration Department, Y. Akçay, A. Tandircioğlu, H. Can and R. Ö. TemelThe Paleozoic section in Murzuq Basin constitutes the main hydrocarbon system. Organic-rich Silurian "hot" shales of Tanezzuft Formation are the primary source rock as widely recognized and proven in most of the North Africa. Paleozoic shales mainly Silurian Tanezzuft Formation are also the main seal in the region. The primary reservoirs are the Ordovician glacio-marine and fluviodeltaic sandstones (which are called Ordovician_SS herein after) in the Murzuq Basin. A key risk in hydrocarbon exploration is the distribution of the postglacial hot shales at the base of the lower Silurian Tanezzuft Formation. During the late Ordovician west Gondwana was located close to the South Pole at high latitude and the Murzuq Basin was lying along its continental margin (Davidson et al., 2000). The "hot" shale distribution is patchy and reflects the residual topography on the upper surface of the Upper Ordovician sediments (Lüning et al. 2000, 2003). The Murzuq Basin is filled with continental Mesozoic and Cenozoic sediments lying unconformably on the marine Paleozoic rocks, which reach a maximum thickness of about 10,000 ft in the basin centre.
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Late Ordovician Eustasy And Glacial Cycles Across The North Gondwana
More LessThe Late Ordovician glaciation was initially (1960-1990) thought to represent a long-lasting icehouse period. In the nineties, the idea was imposed of a much shorter glacial event, possibly catastrophic at the geological timescale. The corresponding glaciation was limited to the Hirnantian, or even to a part of this 1-2 My stage, as suggested by short-lived isotopic excursions and correlative biological turnovers. The sequence stratigraphy of Late Ordovician successions in the palaeo-high latitude North Gondwana setting reveals that at least 3 glacial event similar to the Hirnantian event occurred in the Katian, as indicated by the stacking-pattern of shelf successions including forced regressive system tracts. The latter seem to have their counterpart in low-latitude settings, either in the form of fully developed third-order regressive-transgressive cycles (Laurentia) or in karst horizons (Baltica). The synchronous character of these inferred worldwide glacioeustatically controlled event is however difficult to ascertain as biostratigraphy is essentially based on endemic (Laurentia/Baltica/Gondwana) faunal assemblages. The view of a long-lasting glaciation (> 25 My) including discrete short glacial events (< 1 Ma, intra-Katian events, Hirnantian, base Wenlock) prevails today. The tempos and forcings of these glacial events are however largely debatable, what made their correlation at continental scales questionable. Until recently, most of the glacial features (tillites, striated surfaces, tunnel valleys) were ascribed to the Hirnantian glacial event(s). Only during the corresponding time interval ice fronts indeed reach sedimentary basins around the Gondwana supercontinent, and hence were related to the widespread and well-known glacial record.
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Neoproterozoic And Paleozoic Glaciations On The Arabian Plate And Their Impacts On The Hydrocarbon Accumulations
By M. ŞenalpAt least four major glaciations occurred, and were fully documented from the Arabian Plate of the Gondwana Land over the last billion years. They include two Neoproterozoic (Cryogenian) events and Late Ordovician (Hirnantian) and Permo-Carboniferous events. As the deep gas explorations have been extended into these older successions the relationship between glaciation and hydrocarbon accumulations are better understood. The author of this presentation was actively involved in the exploration and the development stages of the Late Ordovician and Permo-Carboniferous glaciogenic sandstone reservoirs of Saudi Arabia. He has carried out intensive field work to understand the sedimentology, lithofacies stacking pattern, and reservoir quality of different segments of the deep and long glacial paleovalleys to interpret their reservoir quality in the prospective areas (Senalp and Al Laboun, 2000; Senalp and Al-Duaiji, 2001; and Senalp 2006).
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Reconstructing A Source Rock System - Silurian Onlap In Time And Space
By P. SpaakSilurian source rocks are wide spread and charge approximately 9% of the world’s conventionally trapped hydrocarbons. In addition, thick Silurian source beds are seen as unconventional targets for oil and gas and Shell has secured such acreage in China and Turkey. The most prolific source rocks of this age are found in the Middle East and North Africa. They are responsible for numerous conventional hydrocarbon accumulations, including the Arabian ‘super-giants’ (North Dome/South Pars and Ghawar) and major Algerian gas and oil fields (Hassi R’Mel and Hassi Messaoud). In this presentation, the variation in depositional setting for the Silurian source rocks will be illustrated, through a careful reconstruction of the Silurian flood in time and space. Although these source beds typically occur at or near the base of Silurian, some are clearly linked with oceanic upwelling, some accumulated in relatively confined foreland basin settings whereas others were formed on a broad but tectonically and glacially modified Gondwana shelf.
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Glacio-Eustatic Sea-Level Change In The Early Pennsylvanian: Evidence From The Bashkirianmoscovian Boundary Beds In Taurides (Turkey)
Authors D. Altiner, S. Özkan-Altiner, İ.Ö. Yilmaz and A. Özdemir-Atakulng on the Bashkirian- Moscovian boundary beds, corresponds to the last phase of a glacial period encompassing the interval from the latest Visean (mid-Brigantian) through the Late Bashkirian (Tashastinsky to lowermost Asatausky) and the early phase of a non-glacial period from the latest Bashkirian (Asatausky) to the latest Moscovian. Bashkirian-Moscovian boundary beds, made up of carbonate and mixed siliciclastic-carbonate lithologies, are widely exposed along the Tauride Belt in southern Turkey (Özgül, 1976; Altıner & Özgül, 2001). Three overlapping sections spanning the Lower Bashkirian (Askynbashky) to Lower Moscovian (Solontsovsky) beds have been measured and collected on a bed-by-bed basis.
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The Effect Of Mechanical Properties Anisotropy In The Generation Of Hydraulic Fractures In Organic Shales
Authors G. A. Waters, R. Lewis and D. BentleyThe “Evaluation of Shale Resources” has come a long way in the last 10 years and has brought to the industry a much clearer understanding of these challenging reservoirs. The basic understanding of micro porosity and its relationship to organic matter is important for one having to work with shale. This is a starting point for a better understanding of shale production; however this knowledge clearly leads to the necessary requirement of accessing this micro porosity through the process of hydraulic fracturing. This presentation will give a short overview of the evaluation of “Reservoir Quality” and “Completion Quality” before presenting a more detailed discussion on the issue of Mechanical Properties Anisotropy in Shale.
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Derisking Of Unconventional Gas Opportunities: Application Of Basin Modelling
Authors M. Keym, V. Dieckmann, O. Meuric, O. Huvaz, E. Leenaarts, O. Podlaha and E. İdizUnconventional Light Tight Oil (LTO) and shale gas (SG) plays are self-charged systems, relying on the indigenous organic matter as the source of hydrocarbons. The finegrained organic rich sediments or tight layers in their vicinity act with their residual pore space as the reservoirs. Pressure and temperature can significantly increase during burial and even more decrease during erosion and uplift. These changes strongly influence the phase behaviour of the generated and trapped hydrocarbons thereby affecting their flow properties, potential migration routes, retention capacity of the source rock, and predicted volumes initially in place. Shell’s integrated Cauldron Shale Gas Simulator calculates resource density on a regional to basin scale, typically during the opportunity identification and screening phase. Informed decision-making in exploring for such unconventional opportunities relies on integrating all available (i.e., sometimes scarce) data and their associated uncertainties for basin scale physical elements and processes into a working geologic model.
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Stratigraphic And Structural Controls On The Distribution Of Silurian Source Rocks In Northern Gondwana: Results Of A Field Based Study In Southern Libya
Authors J. Howard, G. Meinhold, A. Whitham and D.L. HeronRhuddanian transgressive black shales deposited across northern Gondwana include world class hydrocarbon source intervals in North Africa, Arabia and southern Turkey. The highest TOC values are usually concentrated in one (or more) layers in the lower part of the Silurian succession. These source units are commonly referred to as hot shales because high TOC values are often coincident with elevated uranium contents. Hot shales were deposited during the early stages of the Silurian marine transgression and their distribution was controlled by relief on the underlying depositional surface (Lüning et al., 2003). Understanding how glacial and tectonic processes influenced topography on the pre-Silurian depositional surface and how such topography influenced the deposition of hot shales can therefore reduce risk during hydrocarbon exploration.
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Stratigraphy And Graptolite Ages Of The Lower Silurian “Hot Shales” From The Taurides And Se Anatolia, Turkey
Authors H. Kozlu, V. Sachanski, M. C. Göncüoğlu and Y. GünayTo establish the stratigraphical position and the exact age of the Silurian “hot shales” in the Taurides and SE Anatolia, a number of sections were measured and sampled in detail. Graptolite data obtained from this study suggests that Lower Silurian is almost complete in the Taurides and includes more than one black shale interval. In the Eastern Taurides the measured sections are in Tufanbeyli-Pekmezköy and Sarız-Değirmentaş; additional spot samples were taken from Sarız-Mirzaağa, Tufanbeyli- Armutalan and Saimbeyli-Gürleflen sections. In the Central Taurides, Silifke-Ovacık and Bozyazı-Tekmen sections were measured and spot samples were taken from Silifke-Somaklı section. In the Western Taurides the Antalya-Kemer section was investigated and dated by conodonts from the limestone interlayers. In SE Anatolia, representing the northern margin of the Arabian Platform, Çermik-Southern Korudağ section was measured and the Gerger Çat section was investigated by a number of spot samples. In most of the studies sections in the Taurides, Hirnantian glacio-marine siltstones with channel-type sandstone bands and lenses make up the substratum of the measured sections.
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Silurian-Devonian Boundary In Se Anatolia (1): Organic Matter Variation As A Function Of The Depositional System At The Hazro Area
Authors U. Mann, O. Kranendonck, N. Bozdoğan and C. SoyluAt present, Silurian-Devonian boundary sequences are primarily distinguished by faunal changes which affected several groups of organisms, e.g., graptolites, conodonts, chitinozoans, (Paris et al., 1981; Walliser, 1996). Chlupac and Kukal (1986) described this marine faunal change in comparison with other Silurian bioevents as a minor, relatively gradual but globally traceable event. Nevertheless, the driving forces for this event as well as the parallel occurrence of first land plants, which started to conquer the continents since the Middle Silurian, are still under discussion.
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Cambrian
Authors M.C. Göncüoğlu, O. Elicki, H. Kozlu, S. Gürsu and Middle East Technical UniversityA number of the crystalline rocks with Cambrian radiometric ages are reported in the northern Istanbul-Zonguldak Terrane. Other than in the southern terranes, these arc-type granodiorites intrude or are associated with Late Neoproterozoic metagabbros, orthoamphibolites and pyroxenites (Ustaömer and Rogers, 1999). Overall, the Cambrian rocks are interpreted as representatives of a Cadomian intra-oceanic arc, formed within the Iapetus- Tornquist oceanic lithosphere (Göncüo¤lu, 1997; Göncüo¤lu and Kozlu, 1997). In some successions in the Menderes Massif and the Central Anatolian Crystalline Complex of the Anatolides, rock units very similar to those in the Tauride-Anatolide platform are reported by Kozlu and Göncüo¤lu (1997). The Cambrian in the Taurides shows in general very similar features across the belt (Figure 1) and will be evaluated in detail in the following chapters.
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Sequence Stratigraphy Of The Paleozoic Successions In Saudi Arabia
By M. ŞenalpIn recent years, non-associated gas, condensate, and Arabian super light oil were discovered in the sandstones and carbonates of the Paleozoic successions in Oman, Qatar, Jordan, and Saudi Arabia. The exploration and production wells from these multiple reservoirs have yielded immense amount of data on the subsurface geology of both reservoir and non-reservoir formations. The sequence stratigraphy of the Paleozoic Successions in Saudi Arabia was constructed by using measured stratigraphic sections at outcrops and subsurface data from deep exploration and water wells. The successions have been subjected to a complex tectonic history. The two major tectonic events (Devonian Caledonian and Mid-Carboniferous Hercynian orogenesis), the two episodes (Late Ordovician and Permo-Carboniferous) of the Gondwanaland glaciations, and finally the break-up unconformity during the Late Permian time caused major deformations, regional erosion, peneplanation and deep incisions of valleys on the Arabian Platform. The maximum flooding surfaces were developed as result of melting ice mass during the deglaciation periods. These events are especially obvious in the stratigraphic record, and were used as regional correlation markers with other countries.
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Paleozoic Stratigraphy And Sedimentary Basin Evolution Of Se Turkey
Authors N. Bozdoğan, Research Center and D. PerinçekSE Turkey is a continuation of the Arabian Plate to the north in terms of the geological system (Figure-1). Sedimentary rocks were deposited in several basins in the area since Precambrian time. In order to understand the development of the sedimentary basin of the region, well data, field observations, structural, stratigraphical, sedimentological, micropaleontological, and palynological data and sedimentary features of the neighboring countries were evaluated. This review is based on the results from studies such as Bozdoğan and Erten (1990), Perinçek et al. (1992) and Bozdoğan and Ertug (1997).
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Early Ordovician Trace Fossils From The Amanos Mountains (Ne Osmanıye, Se Anatolia)
Authors H. Demircan and D. UstaTrace fossils are found in the Lower Ordovician quartzarenite shale alternations, to the northeast of Osmaniye in southeastern Turkey. The sequence contains abundant, diverse, and well-preserved arthropod ichnofossil assemblages comprising nineteen ichnogenera (Arthrophycus isp., Circulichnis isp, Cruziana isp. , Cruziana furcifera, Cruziana imbricata, Cruziana rugosa, Cruziana goldfussi, Deadulus isp., Didymaulichnus isp., Diplocraterion isp., Monocraterion isp., Monomorphichnus isp., Teichichnus isp., Skolithos isp., Palaeophycus isp., Planolites isp. Rusophycus isp. Protovirgularia isp., Trichophycus isp.). They are included in the Cruziana rugosa Group (Cruziana furcifera, C. goldfussi, C. rugosa) and can be used for chronostratigraphy throughout the Ordovician (Tremodocian to Arenigian). The presence of Cruziana furcifera, C. goldfussi, C. rugosa, and C. imbricata in the studied section indicate that the unit is of Early Ordovician (Tremodocian-Floian) age. These trace fossils belong to the shallow marine subtidal low-energy Cruziana ichnofacies.
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Late Devonian Conodonts And Ostracods From The Gümüşalı Formation (Feke, Adana), The Eastern Taurides, Turkey
Authors Ş. Çapkinoğlu, A. Nazik and E. ŞekerThe Devonian sequences of Eastern Taurides are divided into three formations in the previous works: Lower Devonian Ayı Tepesi, Middle Devonian Şafak Tepe and Upper Devonian Gümüşali Formations (Özgül et al, 1973; Metin et al, 1983; Yılmaz 2004; Göncüoğlu et al, 2005). The Upper Devonian Gümüşali formation of the eastern Taurides is a terrigenous-carbonate rock sequence about 600 m thick (Figure 1). Its basal portion is made up of dark grey limestones interbedded with shale or marly shale. The middle part consists of an alternation of limestone and shale with quartz sandstone and siltstone interbeds. The upper 85 meters is dominated by dark grey, silty-sandy, spiculitic limestones. Palaeontologic and sedimentologic data mainly indicate a shallow subtidal depositional environment. Late Devonian conodont and ostracod faunas were obtained from this formation.
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Cruziana Pavements In The Kümperli Region, Nw Kahramanmaraş, Se Of Turkey
Authors H. Demircan, D. Usta, Ş. Ateş and M. BeyazpirinçWell-preserved Cruziana pavements have been recently extraordinarly found in Lower Ordovician units of Amanos Mountain near NW Kahramanmaraş-Kümperli area (SE, Turkey). Cruziana pavements lithologically presents Lower Ordovician siliciclastic. The morphology and orientation of scratchmarks in these traces suggest that they may have been constructed by as trilobite traces, although some may have been produced by different types of arthropods. The traces are assigned to the Cruziana rugosa group. Ichnofossils have been useful particularly in depicting the Precambrian/Cambrian and Cambrian/Ordovician boundaries (Crimes, 1968, 1969; Seilacher, 1970). Many of these correlations imply the use of various species of the ichnogenus Cruziana as biostratigraphic indicators, because their morphological complexity is high and commonly corresponds well to specific groups of trilobites (Seilacher, 1990). The limitation of Cruziana to Paleozoic strata corresponds to the stratigraphic range of trilobites and, thus, has been inferred to have biostratigraphic significance (Crimes, 1968, 1969; Seilacher, 1970, 1990, 1994). Trace fossils commonly are preserved in sequences devoid of other fossils and, thus, may provide useful biostratigraphic data in certain situations. This papers objective is to discuss the significance of abundant, large Cruziana which were collected from the Lower Ordovician units of Amanos Mountain near NW Kahramanmaraş-Kümperli area (SE, Turkey). The morphology, biostratigraphic implications, ethological significance, and possible taxonomic identity of trace fossils are addressed.
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Corals Of The Upper Viséan Microbial-Sponge-Bryozoancoral Bioherm Of Kongul Yayla (Taurides, S Turkey), Palaeobiogeographic Relations
By J. DenayerThe Mississippian (lower Carboniferous) bioconstructions are well diversified and widely distributed (Aretz & Herbig, 2003), particularly in the upper Viséan strata. Such a reef was described from the Kongul Yayla outcrop located between Hadim and Taşkent (Central Taurides, South Turkey). The reef is included in the Zindancık Member of the Kongul Formation that belongs to the Bolkar Dağı tectonostratigraphic unit (Altıner & Ozgül 2001). Previous studies in this area (Ozgül 1997, Turan 2000) already recognized the reefal character of the Kongul Yayla outcrop, but never described it. Ozgül (1997) and Altıner & Ozgül (2001) attributed from Viséan to Serpukhovian age for the whole Kongul Formation. But, Ekmekçi & Kozur (1999) indicated a Moscovian age for the entire formation based on only four conodonts from one single locality. At first sight, the dating of the Kongul Formation is not precise. The coral association found in Kongul Yayla indicates an late Viséan age for the reef (see results below).
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Stratigraphy And Palaeogeography Of The Hasawnah Formation (Cambrian, Al Qarqaf Arch, Central-Western Libya): Data From Detrital Zircons And Trace Fossils
Authors M.M. Altumi, O. Elicki, U. Linnemann, M. Hofmann and M.C. GöncüoğluFor central-northern Africa there is a significant knowledge gap to be filled in order to create a consistent reconstruction of the dynamic evolution of this entire palaeogeographic region. This is of exciting interest, because for some areas there is also some economic aspect where included sediments, as in Libya, are significant elements of source rock or reservoir architecture or if they denote important aquifers. In Libya, early Palaeozoic rocks are mainly exposed at the margins of large intracratonic basins in the centralwestern to southwestern region of the country (Ghadamis Basin, Murzuq Basin), in the southeast (Al Kufrah Basin), and in the Tibesti Mountains in the south. One of the most important outcrop areas is in the Jebel Hasawnah (also called Jebel Fezzan or Jebel Al Qarqaf) of the Al Qarqaf Arch (AQA). The amplitude of the uplift is about 6000 m (up to 800 m elevation at present surface) in the AQA area relative to the basement level in the northern Ghadamis Basin area where this level is about 5200 m below surface. The AQA largely separates the Ghadamis Basin in the northwest from the Murzuq Basin in the south (Fig. 1) and represents the northernmost basement outcrop of the so-called Saharan Metacraton.
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U-Pb La-Sf-Icp-Ms Dating Of Detrital Zircons From An Upper Carboniferous Quartzite In The Sıyah Aladağ Nappe, Yahyali-Kayserı, E Taurides: Source Area Characteristics
Authors T. Ustaömer, A. Gerdes, P.A. Ustaömer and A. RobertsonEarly Palaeozoic sediments and/or meta-sediments in several crustal blocks in the Pontides tectonic belt of N Turkey, including the ‹stanbul terrane, Central Sakarya, Armutlu Metamorphics and Pulur Metamorphics revealed dominantly N Gondwanan source areas (P.A. Ustaömer et al. 2011, 2012; T. Ustaömer et al. 2012). In contrast, Late Paleozoic sediments in several of these crustal blocks indicate that Variscan magmatic and metamorphic rocks represent significant sources in addition to Pan-African and older crustal sources (N. Okay et al. 2011; our unpublished data). We have carried out a detailed provenance study of Early and Late Palaeozoic sedimentary rocks exposed in several thrust sheets and also within the relative autocthon of the Tauride belt of S Turkey: 1) to define the source ages and 2) to determine if a Variscan terrane was a source for the Late Palaeozoic sediments. In this study we report preliminary data from an Upper Carboniferous quartzite exposed in the Siyah Alada¤ Nappe of E Taurides. The quartzite studied comes from ca. 40 meters below the Girvenella zone and it is intercalated with neritic limestones and shales.
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Silurian-Devonian Boundary In Se Anatolia (2): Present Stage For The Biostratigraphic Positioning Of The Boundary Based On Brachiopods, Conodonts, Ostracods And Palynomorphs At The Hazro Area
Authors F.W. Luppold, R. Brocke, C. Doyen and U. MannIn 1980, Weyant in Fontaine et al. mentioned Spathognathodus inclinatus for the lower part of the section (Dadas I). Together with other fossilgroups they classified this part into the Lower Budnanian substage of the Bohemian classification (Upper Wenlockian to Upper Ludlowian). But still the correct paleostratigraphic position of the Silurian-Devonian boundary in the Hazro area of SE-Anatolia is unclear. This paper provides a summary of paleontological findings concerning brachiopods, conodonts, ostracods and palynomorphs for this area.
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Recent Stratigraphic Developments Regarding The SıPahıLı Formation Of Early Cambrian Age
More LessThe area between Silifke and Anamur provides a good opportunity to investigate stratigraphic and tectonic problems of the Central Taurus Belt. This area has been subjected to very detailed geological investigations since 1975. All lithostratigraphic units of this region ranging in age from Cambrian to Miocene have been carefully identified and named. The area has been mapped in a scale of 1/25.000. Geological reports of these investigations are existed in the files of the General Directorate of MTA (Demirtaşlı, 1982, 1983). Results of these geological investigations have also been published (Demirtaşlı, 1984, 1985). In spite of all these unpublished and published geological data some investigators studied in this area claimed that the age of the Sipahili Formation is Cretaceous (Özalp and Demirkol, 2003; Özgül and Kozlu, 1993). Very recently samples have been collected from various levels of the Sipahili Formation yielded Early Cambrian conodonts and trilobites. Determination of these samples were made by Prof. Dr. İsmet Gedik, Karadeniz Technical University.
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Ordovician
Authors H. Kozlu, J.F. Ghienne and Istanbul UniversityOrdovician successions in the North Gondwana are best understood in the framework of a Lower Paleozoic development. In the Cambrian-Ordovician successions of southern Turkey (Taurus chain or Taurides, Figure 1) and SE Turkey (Border Folds of the Arabian Plate), four major depositional sequences have been defined based on recognition of major transgressive events and subsequent shelf progradations (Ghienne et al., 2010).
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Palynofacies And Bulk Organic Geochemistry Of Permian Clastics In The Eastern Taurids: Implications For Hydrocarbon Potential
Authors E. Stolle, M. N. Yalçin and H. KozluMid to Upper Permian strata from road cuts near Sarız and Feke (Eastern Taurids, Fig. 1) were sampled for palynological study. Most of the claystone samples are found to be rich in palynological organic matter, and based on previous work the Permian deposits near Feke have some source rock potential (İlleez et al. 1994; Demirel and Kozlu 1997). A study, including organic geochemical and palynological investigation, was undertaken to more fully evaluate the source rock potential for this area.
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The Floristic Migration At The End Of Palaeozoic Times
Authors T. Dimitrova and C. ClealIn Middle Pennsylvanian times there were at least two biomes in tropical Euramerica: (1) wetlands known as coal swamps and (2) seasonally dry environments dominated by conifers, peltasperms and other gymnosperms (DiMichele & Aronson, 1992; Dimitrova et al., 2011). During late Middle Pennsylvanian and Late Pennsylvanian times there was a progressive change in the swamp vegetation, due to a combination of tectonically-driven landscape modification and climate change (Cleal et al., 2010, 2011). The partial removal of the arborescent lycopsids that represented the dominant ecomorphs of the swamp vegetation, removed patterns of incumbent advantage and permitted a lottery-like period of ecological and evolutionary escalation (DiMichele & Phillips, 1996). The result was that the coal swamps initially became dominated by fast-growing, weedy tree ferns. Eventually, in late Late Pennsylvanian and Permian times the swamps became fully drained and the conifer-peltasperm dryland vegetation came to dominate the lowland areas (Kerp, 1996).
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Analysis Of The Ironstones (Upper Lochkovian And Middle Givetian) Within Carbonate Platform Succession (Nw Anatolia): A Paleoclimatic Approach
Authors İ.Ö. Yilmaz, M.C. Göncüoğlu, G. Saydam-Demiray and İ. GedikPaleoclimate of the Devonian is generally known as warm and carries the important contribution of plant communities. Climate in the Lower Devonian is generally arid and dry in the southern hemisphere, and characterised by presence of evaporites and paleosoils. In the Middle Devonian, it presents a relatively warmer snap. This warming is reflected as presence of coal desposits. In the Upper Devonian, there is cold snap and associated with presence of glaciers (Boucot, 2009). Joachimsky et al (2009), on the other hand, suggested that the lower – middle Givetian was characterised by cooler T with about 20-22°C and upper Lochkovian by warm tropical temperatures with around 30 °C using global isotope data set.
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Silurian Organic-Rich Source Rocks Of Russia
Authors O.K. Bogolepova, A.P. Gubanov and M.N.D. KayeThe Silurian interval in the history of the Earth was characterized by widespread deposition of source rocks. They generate 9% of the world’s petroleum reserves (Klemme and Ulmishek 1991) and are known from many parts of the world in Europe, Africa, Asia, North and South America, and Australia. At present, 26 basins are characterized by the presence of Silurian organic-rich sediments, represented mainly by graptolite black shale and bituminous cephalopod (“Orthoceras”) limestone. Of particular interest and detailed study so far is the early Silurian “hot” shale of the Middle East and North Africa (Lüning et al. 2000). However there is an apparent lack of data and uncertainties from the other areas of potential Silurian source rock distribution (e.g. Baltic states, and the territory of Russia).
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Shale Gas Assessment Of The Silurian Formations Of Turkey
By Ş. ŞenShale gas studies in US, Canada and Europe have grown in recent years. Organic matter content (TOC > 1%), maturity (Ro > 1% or Tmax > 450 °C) and mineralogy (high percentages of quartz and low percentages of clay) are essential for shale gas assessment (Ross and Bustin, 2008; Jarvie et al., 1997). The Western Pontide, Eastern Tauride and SE Anatolia of Turkey contain the Silurian hot shales (Fig 1). Organic matter content and maturity trends of the Silurian shales of Turkey have been studied in the Western Pontide by Harput et al. (1999), in the Eastern Tauride by İlleez et al. (1994), Demirel and Kozlu (1997), Korkmaz et al. (2008) and in the SE Anatolian by Aydemir (2011). Mineral content of the Silurian shales in the Pontide have been studied by Bozkaya et al (2011). Aim of this study is to interpret the Silurian shale gas potential of Turkey in the light of the published data and investigation of this study.
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Silurian
Authors H. Kozlu, V. Sachanski, M.C. Göncüoğlu and Istanbul UniversitySilurian rocks are reported from the Istanbul-Zonguldak Terranes in NW Anatolia, in the Taurides-Anatolides, as well as in the SE Anatolian Autochthon. The NW Anatolian Istanbul-and Zonguldak terranes were separated from the main body of NW Gondwana as a part of the Avalonian-Central European Terrane Assemblage (Perigondwanan Terrane Assemblage e.g. Nance et al, 2012) and drifted towards N across the Rheic Ocean. By this the differences (e.g. Lakova and Göncüo¤lu, 2005) in the paleogeographical setting has resulted in dissimilarities in litho- and biostratigraphy (Figure 1) between the Northern (Istanbul-Zonguldak) and Southern (Taurides-SE Anatolian Autochthon) areas (Göncüo¤lu and Kozlu, 1997). In the former group there are also differences in the lithostratigraphy (e.g. Kozlu et al, 2002a). In the Anatolides, the metamorphic edge of the Tauride-Anatolide platform, Middle and Upper Silurian low-grade metamorphic turbidites with black lydites and brownish limestone bands had been reported only from the Konya area, dated by conodonts (Göncüo¤lu et al, 2000).
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Devonian
Authors M.N. Yalçin, A. Wehrmann, E. Schindler, I. Yilmaz, V. Wilde, A. Nazik, N. Bozdoğan, R. Özkan, H. Kozlu, R. Brocke and Istanbul UniversityNon-metamorphic Devonian units of different litho-types and of different paleogeographic origin in Turkey are parts of thick Paleozoic sedimentary successions of the Pontides, Taurides and the Arabian Plate. A broad overview about the Devonian of Turkey resulting from numerous previous studies is given by Yalç›n& Y›lmaz (2010). Devonian rocks of Gondwanan origin are represented as deposits of the Arabian Plate in Southeastern Anatolia and along the entire mountain belt of the Taurus in southern Turkey. At present, both terranes are separated from each other by an Alpine suture zone, the Bitlis-Zagros Orogenic Belt (fiengör and Y›lmaz, 1981). However, during the almost entire Paleozoic they were parts of a continuous terrane at the northeastern margin of Gondwana. The continuity of the Paleozoic units in Southern Turkey, which were deposited on the northern margin of northeastern Gondwana, ended at the beginning of Mesozoic due to the opening of the Neotethys Ocean. The southeastern part of the former Paleozoic terrane remained on the northern margin of the Arabian Plate to the south of the new ocean, while the Taurus and Menderes Blocks attained a position north of it. Closure of the Neotethys Ocean by subduction and subsequent collision led to imbrication of the Menderes-Taurus Block and many slices were thrust onto each other. Thus, collision-related tectonics resulted in the complex structure of the Taurides and a very complicated geology.
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Carboniferous
Authors D. Altiner, N. Şahin, H. Sancay and Middle East Technical UniversityFollowing the pioneering studies of Blumenthal (1944) who reported the presence of Permocarboniferous successions in the eastern Taurides the Carboniferous in the autochthonous belt was named for the first time in an unpublished MTA report as the Ziyarettepe Limestone by Demirtafll› (1967). The type-locality is near the Gümüflali Village located between the towns of Tufanbeyli and Sar›z. This formation was later studied by Özgül et al. (1973) in the outcrops close to the Naltafl Village located to the SW of the Town of Tufanbeyli. These authors modified the name of the unit as the Ziyarettepe Formation due to the heterogenous nature of its lithology and defined the stratigraphic position of the formation as conformable over the Gümüflali Formation of Late Devonian age and unconformable with the overlying Y›¤›l›tepe Formation of Permian age. According to Özgül et al. (1973) the formation consists of three distinct lithologies from bottom to top. Overlying the sandstones of the Gümüflali Formation, the unit, measuring 340 m, starts with limestoneshale alternations at the base, continues with a distinct quartz sandstone in the middle and is capped by a limestone unit at the top. They assigned an Early Carboniferous age to the formation based on brachiopods and corals. Later, Özgül (1976) in his classification of the tectonic units of Taurides depicted the stratigraphy of the Tufanbeyli region including the Ziyarettepe Formation as one of the reference sections of his Geyik Da¤› Unit. Demirtafll› et al. (1978) studied the Carboniferous Ziyarettepe Formation from the Tufanbeyli-Sar›z region in the eastern Taurides. Along the road section from P›narbafl› to Sar›z, they divided the formation into three informal members. Overlying the carbonates and clastics of the uppermost Devonian (Etroeungtian ?) the lower member consisting of bituminous, platy and argillaceous limestones containing brachiopods were assigned to the Lower to Middle Tournaisian. The overlying member composed of shale, sandstone and sandy limestone intercalations was considered as Middle to Upper Tournaisian based again on brachiopods. The third member comprising mainly limestones was studied with corals, brachiopods and foraminifers and a Middle Tournaisian to Early Visean age was given to the unit. Following these studies the Ziyarettepe Formation of Carbonifeorus age was recognized and studied in several localities of the eastern Taurides, comprising Gürün-Sar›z-Tufanbeyli-Saimbeyli-Feke and Kozan areas both for stratigraphic and petroleum exploration purposes (Kurtman, 1978; Metin et al., 1983, 1986, 1990; Tutkun, 1984, Demirel & Kozlu, 1997; Demirel, 2004 and Özgül & Kozlu, 2002). Among these studies, Metin et al. (1986) made a considerable modification in the nomenclature of the formation. These authors named the lower part of the unit comprising gray coloured, thin- to medium-bedded carbonates and detritics as the Tuzludere Formation and the overlying sandstones as the Kuflkayas› Sandstone. They restricted the definition of the Ziyarettepe Formation to a limestone level occurring in the upper part of the unit and renamed it as the Ziyarettepe Limestone. In more recent years, Ero¤lu-Nalc›o¤lu (2003) carried out a study based on brachiopods in the lower part of the Ziyarettepe Formation named as the Naltafl Member by Plodowski & Salanc› (1990). According to Ero¤lu-Nalc›o¤lu (2003) this member is Late Famennian to Tournasian in age and the Devonian-Carbonifeorus boundary lies at the base of bituminous shales overlying the sandy or silty limestone-marl alternations of latest Famennian age. Göncüo¤lu et al. (2004), following Plodowski & Salanc› (1990), described the Ziyarettepe Formation in a fourfold subdivision. The lowermost sandy limestone with dark marly limestone intercalations was defined as the Naltafl Member of Plodowski & Salanc› (1990) who assigned a Strunian age (latest Devonian) to this unit based on brachiopods, trilobites and palynological data. Göncüo¤lu et al. (2004) also reported some conodont data of latest Devonian age from this unit. The rest of the succession comprising black shale; dark coloured, thin-bedded clayey limestone and sandstone; marly and sandy limestone, shale and cross-bedded sandstone and the uppermost limestone level was placed in the Carbonifeorus.
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Permian
Authors D. Altiner, N. Şahin and Middle East Technical UniversityDefined for the first time in an unpublished report by Demirtafll› (1967) the type section of the Y›¤›l›tepe Formation is located 1 km south of the Kataras› Village in the Tufanbeyli area. Özgül et al. (1973) studied this formation both in the Tufanbeyli and Naltafl areas and described the formation as consisting of two contrasting lithologies. Measuring 200 m in thickness, the unit starts at the base with quartz sandstones including pockets of bauxite and continues upward with a thick carbonate deposit rich in algae and foraminifera. According to Özgül et al. (1973) the formation rests on the older Paleozoic units with an unconformity and is overlain conformably by the Kataras› Formation consisting of argillaceous and silty limestones, claystones and shales. Özgül (1976) reillustrated the Y›¤›l›tepe Formation in the generalized columnar section of the Tufanbeyli region depicting the rocks of Cambrian to Eocene age as one of the reference sections of his Geyik Da¤› Unit largely exposed in the eastern Taurides. Özgül (1976) defined in the Y›¤›l›tepe Formation two distinct quartz sandstone levels, one at the bottom of the formation overlying the unconformity surface and the second as a layer intercalated within the carbonate rocks. Demirtafll› et al. (1978), mentioning about the type section of the formation measuring 800 m at Y›¤›l›tepe, described the base of the Y›¤›l›tepe Formation along the P›narbafl›-Sar›z road with a distinct bauxite level. According to these authors this lithology defines the unconformity between the Ziyarettepe Formation of Early Carboniferous age and the Y›¤›l›tepe Formation with well-bedded limestone levels intercalated with carbonaceous black shale partings. Demirtafll› et al. (1978) stated also that the Y›¤›l›tepe Limestone is unconformably overlain along this section by the Köro¤lu Tepe Limestone of Jurassic to Early Cretaceous age. The Y›¤›l›tepe Formation has been mapped and studied later in several different localities of the eastern Tauride autochthon including Gürün, Sar›z, De¤irmentafl, Tufanbeyli (Keklikoluk-Kataras›), Do¤anbeyli-Obruktafl, Naltafl, Saimbeyli, Himmetli-Ümmetufla¤›, Feke and Kozan areas (Kurtman, 1978; Zaninetti et al., 1981; Metin et al., 1983, 1986, 1990; Tutkun, 1984; Alt›ner, 1984; Yetifl, 1988; Atabey, 1993; Atabey et al., 1997; Demirel & Kozlu, 1997; Demirel, 2004; Özgül & Kozlu, 2002; Göncüo¤lu et al., 2004). Among these studies reporting only the known stratigraphic description of the Y›¤›l›tepe Formation Metin et al. (1983) gave more information about the type locality of the Y›¤›l›tepe Formation located 30 km southwest of the Town of Sar›z, close to the Kataras› Village. According to these authors, the formation, overlying the Gümüflali Formation of Late Devonian age, starts with a bauxitic level at the base and continues upward with well-bedded limestones intercalated with dark coloured shale beds. Apart from the routine paleontological identifications given in the fossil lists of most authors who mapped and studied the Y›¤›l›tepe Formation there are basically three important paleontological studies. Sakagami (1976) reported the bryozoa assemblages from the Saimbeyli area but without too much emphasis on the chronostratigraphic value of these fossils. The most important plaeontological study was carried out by Zaninetti et al. (1981) who studied four sections from the Naltafl area and described the foraminifers of the Y›¤›l›tepe Formation resting on the Ziyarettepe Formation of Mississippian age. These authors, after giving detailed taxonomical descriptions of foraminifera including biseriamminids, hemigordiopsids, pseudovidalinids, divided the Y›¤›l›tepe Formation into three chronostratigraphic intervals as Upper Murgabian (=Wordian), Capitanian/Djulfian (=Capitanian to Wuchiapingian) and Lower Dorashamian (=Lower Changhsingian). They considered a stratigraphic gap corresponding to the Late Changhsingian between the Y›¤›l›tepe Formation and the base of the Kataras› Formation of Early Triassic age.
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The Presence Of The Aladağ And Yahyali Nappes In The Eastern Taurides (Afşın-Malatya) And Their Tectonostratigraphic Characteristics
Authors Y. Bedi, H. Yusufoğlu, D. Usta and C. OkuyucuIn the study area located at Eastern Taurides, there are different structural units with different lithology, age and degree of metamorphism, displaying thrust fault tectonic relationship with each other (Figs.1a,b). These from bottom to top, are volcanics and pelagic sediments of Middle Triassic - Cretaceous Koçali Complex (Perinçek, 1978), amphibolite facies schist and marble of Precambrian - lower Paleozoic Pütürge Metamorphics (Perinçek, 1978) and Guleman Ophiolites (Erdoğan, 1977). The Pütürge Metamorphics are cut by Upper Cretaceous Şifrin granitoides of mafic affinity. Both two structural units are initially overlain with an angular unconformity by the Lower - Middle Eocene volcano-sedimentary sequence of Maden Complex (Perinçek, 1978) including blocks of different rock types ranging in age from Devonian to Late Cretaceous. This south-originated structural sequence along thrust fault is tectonically overlain by north-originated sequence which comprises from bottom to top, Bodrum Nappe (Şenel et al, 1989), Yahyalı Nappe and Aladağ Nappe (Aladağ Unit; Özgül, 1976).
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