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A chert-pelagic carbonate formation within the mass flow deposits of the Palaeotethyan Karakaya Complex (mélange) in Ankara has yielded poorly preserved radiolaria. The critical fauna: Paronaella claviformis (Kozur and Mostler), Canoptum cucurbita (Sugiyama), Canoptum inornatum Tekin and Canoptum levis Tekin is the late Early Carnian to the early M...
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... to the overlying limestone-chert- mudstone package with fossiliferous samples is marked by slightly recrystallized beige limey mudstones. Fig. 2. Geological map of the area between Ortaköy and Gökceyurt (modified from the 1/100,000 scale MTA geological map compiled by Dönmez et al., 2008). The limestone-chert-mudstone package is about 3.5 m thick (Fig. 4) and can be followed more than 100 m along-strike at the right bank of the Ballica Creek to the north of the Mihli Hill (Fig. 2). The outcrops at the feet of the high-voltage energy trans- mittance mast are the most complete ones. The lower ninety cen- timeters of the package includes pinkish gray limestone with pink marly bands. The ...
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... at the feet of the high-voltage energy trans- mittance mast are the most complete ones. The lower ninety cen- timeters of the package includes pinkish gray limestone with pink marly bands. The overlying red mudstone band of about 1 m thick includes intervals of brick-red radiolarian chert layers that range between 5 and 10 cm in thickness (Fig. 4). The cherts are locally offset by microfaults and cut by quartz-veins. Five samples were taken from these chert layers, from which only two yielded radi- olarians. The host red mudstones are laminated and include car- bonate and mica-rich ...
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... fossiliferous package is overlain by gray and greenish gray shales, transitional to the overlying green silicified shales and green cherts (Fig. 4). The overlying succession is characterized by a thick package of light gray and greenish greywackes alternating with quartz-siltstone, quartz-arenite and arkosic ...
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... the five samples, only OR-1 and -2 from the lowest chert bands (Fig. 4) yielded radiolarians. Although they are not well-pre- served due to deformation, and not too much diverse (Fig. 5), four species occurring in the assemblage (Paronaella claviformis (Kozur and Mostler), Canoptum cucurbita (Sugiyama), Canoptum inornatum Tekin and Canoptum levis Tekin) are well-enough for dating (Fig. ...
Citations
... 1972, 1979, 1981Lahm, 1984). Furthermore, similar radiolarian assemblages have also been the subject of some research in Turkey (e.g., from the Huglu Tuffite in the Beysehir-Hoyran Nappes by Tekin (1999); Bornova Flysch Zone in the Izmir-Ankara-Suture Zone by Tekin and Göncüoglu (2007); the Alakircay Nappe of the Antalya Nappes by Varol et al. (2007); the Eymir Unit of the Karakaya Complex by Sayit et al. (2011); the Arkotdag Mélange in the Intra-Pontide Suture Zone by Tekin et al. (2012) and the Turunc Unit of the Lycian Nappes by Sayit et al. (2015). This radiolarian association corresponds to the Tetraporobrachia haeckeli Radiolaria Zone by Kozur and Mostler (1994) and Kozur (2003), indicating a late Early Carnian age (Fig. 9). ...
... The Karakaya Complex is unconformably overlain by the Liassic sediments ( Altiner et al., 1991 ). The Complex is made up of two major lithological components; (i) mafic unit called the Nilüfer Unit ( sensu Sayit et al., 2010 ), (ii) clastic-dominated unit named the Eymir Unit ( Sayit et al., 2011 ). The Nilüfer Unit consists predominantly of variably metamorphosed mafic igneous rocks associated with volcaniclastic rocks, limestone, mudstone, and chert. ...
The Nilüfer Unit of the Karakaya Complex (northern Turkey) preserves the remnants of the voluminous Triassic Tethyan magmatism. In the Imrahor area (Ankara), the Nilüfer Unit is characterized by a megablock consisting of hydrothermally altered basalts, gabbros, and subordinate wehrlitic cumulates. These lithologies display marked positive Nb anomalies with depleted Th/La ratios and varying degrees of LREE enrichment. They can be subdivided into two groups based on Nb/Nb*, which are not related to each other via fractional crystallization or extent of partial melting. With their strong Nb-kick and broad La/Sm range, the Imrahor lithologies are more akin to FOZO (Focus Zone)- or C (common component)-type melts than EM (Enriched Mantle) and HIMU (high μ). The Zr-Nb systematics reveals that melt mixing was an essential process in the petrogenesis of these mafic rocks. Based on geochemical modeling, the trace element systematics of the İmrahor lithologies can be explained by melting metasomatized oceanic lithospheric mantle (OLM) infiltrated by very low-degree melt fractions. The metasomatized OLM may represent a recycled, plume-related material that has generated Nb-enriched melts during the Triassic Tethyan magmatism.
... Furthermore, in the eastern Sakarya Zone lying to the east of Tokat (Fig. 1) there is no autochthonous sedimentary and igneous record formed in a time span of Permian to end of Triassic, which corresponds to two-thirds of the entire life of the Paleotethys Ocean. Concrete evidence for the presence of a Permo-Carboniferous ocean comes from the exotic blocks of Carboniferous and Permian limestones and radiolarian cherts in the Triassic accretionary complexes of the western Sakarya Zone (Okay et al., 2011;Sayit et al., 2011;Bortolotti et al., 2018;Tekin et al., 2019). It remains to be elucidated whether all these Carboniferous and Permian exotic sedimentary blocks as well as the Triassic, Jurassic and Cretaceous ophiolitic mélanges really belong to the Paleotethys Ocean or daughter back-arc oceans, such as the Triassic Karakaya and the northern branch of the Neotethys Ocean. ...
... Many studies (stratigraphic and geochemical) have been carried out on the Karakaya Complex magmatic and metamorphic rocks in the Sakarya Terrane (Okay and Göncüoğlu 2004). However, data on the origin and tectonic environment of the metaclastic rocks of the Karakaya Complex are limited (Erol 1956;Akyürek et al. 1984;Sayit et al. 2011;Sayit and Göncüoglu 2013;Şengün 2022a, b). The purpose of this study is to determine the provenance and tectonic setting of the lowgrade metamorphic Karakaya Complex sandstones based on their major, trace, and rare earth element compositions located within the Sakarya Terrane in NW Anatolia and central NE Anatolia. ...
... According to geochemical results, the Permian-Triassic Eymir unit in the Ankara region of the Sakarya Continent is of continental origin (Sayit et al. 2011). Örenli Metamorphics of the Biga Peninsula in NW Anatolia showed intermediate and felsic source rocks (Şengün 2022a). ...
The Permian–Triassic Karakaya Complex (KC), related to the Palaeotethys, is located within the Sakarya Terrane in northern Turkey and is subdivided into two parts, the Lower Karakaya (LKC) and Upper Karakaya (UKC). UKC units usually consist of meta(sandstone) strata. This study contributes to their provenance and geotectonic settings by revealing the petrographic and geochemical properties of (meta-)sandstones in the UKC units from the northwest and central northeast Anatolia. KC (meta-)sandstones have middle-to-poor sorting; are unmatured; have microlamination, mineral orientation, and slaty and crenulation cleavages; and have muscovite/biotite-chlorite stack/pod structures. Sandstones contain polycrystalline and monocrystalline quartz, feldspar (plagioclase, orthoclase, and rare microcline), rock fragments (basalt, granite, quartzite, schist, phyllite, and limestone), heavy minerals (muscovite, biotite, zircon, epidote, apatite, hematite, and goethite), matrix (chlorite and sericite), and cement (calcite and silica). Plagioclase Alteration Index (PIA), Chemical Index of Alteration (CIA), and Chemical Index of Weathering (CIW) values of (meta-)sandstones indicate that the silicates had an intermediate degree of chemical weathering/alteration. The total REE concentrations of (meta-)sandstones are 38–276 ppm, and they show 193–10 (La-Lu) times the enrichments with negative Eu anomalies in comparison with chondrites. The Al2O3/TiO2 ratios of the UKC sandstones indicate that the sediments were derived from felsic and intermediate igneous rocks. The major and trace element geochemistry of the KC sandstones was associated with an active margin setting. (Meta-)sandstones from the LKC-UP and UKC units were largely derived from magmatic and sedimentary sources that indicate extensional basins, respectively.
... In both parts, there is a common lithological assemblage dominated by metabasic rocks associated with volcaniclastics, recrystallized limestones, and pelagic sediments, called "the Nilüfer Unit" (sensu Sayit et al., 2010). Another lithological package, which is again typical in both tectonic units but somewhat restricted to the Upper Karakaya Complex, is characterized by the very low/low-grade metamorphosed clastics, known as "the Eymir Unit" (Sayit et al., 2011;Sayit and Göncüoglu, 2013). ...
... These clastics are variably deformed and reflect the sign of very low-grade metamorphism. The clastic lithologies, which form the dominant component of the Upper Karakaya Complex in the Ankara region, are known as or a part of the "Dikmen Greywackes" (Erol, 1956), the "Elmadag Formation" (Akyürek et al., 1984), the "Bayramdere and the Kisiküstü formations" (Kocyigit, 1987), and the "Eymir Unit" (Sayit et al., 2011). ...
... Rock units belonging to the Upper Karakaya Complex including a variety of different blocks are exposed to the southern area of Ankara City, (Fig. 1). Whereas Sevin et al. (2015) described a rather continuous succession of Carboniferous to Permian age for this area, our detailed study focusing on the outcrop around Gökcehüyük village reveals that at least five different blocks are present in the Triassic matrix of this complex, which has been dated previously as the latest Permian -Early to Late Triassic (in the Ankara region) on the basis of foraminiferal and radiolarian fauna acquired from the limestones and cherts interbedded with the clastics (Akyürek et al., 1979(Akyürek et al., , 1984Göncüoglu et al., 2004;Sayit et al., 2011;Duru et al., 2012, Fig. 2). These are: ...
The Upper Karakaya Complex, belonging to the Karakaya Complex, includes different blocks and tectonic slices
within a Triassic sheared matrix. This wide-spread unit mainly exposed in northern Turkey also crops out to the
southern part of Ankara city near Gokcehüyük village. Instead of a continuous sequence of Carboniferous to Permian age described in a previous study, five different blocks of various origins and ages are identified in this study. One of the pelagic blocks composing of cherty limestone includes radiolarian and conodont assemblages
typical of Spathian age, representing the Triassospathodus homeri Conodont Zone. It corresponds also to the Hozmadia ozawai Radiolarian Zone although the zonal guide could not be obtained from the radiolarian assemblage. This is so far the first recovery of pelagic assemblages (radiolarians and conodonts) from the Karakaya
Complex. This result clearly indicates that pelagic sedimentation took place in the Karakaya Complex during late Early Triassic time. Compared to previous studies, it can be stated that radiolarian cherts have been deposited in the Karakaya Complex in two different time span from Middle to Late Devonian and Late Permian (Changhsingian) to early Late Triassic (Carnian) time, respectively.
... The limestone blocks may vary in size, from a few meters to several hundred meters, and are made up of coarse-grained calcite. This basement is correlated with the Triassic Karakaya Complex elsewhere in the SCT (Tüysüz et al., 1995;Okay and Göncüoğlu, 2004;Sayıt and Göncüoğlu, 2009;Sayit et al., 2011). This basement is disconformably overlain by red metaconglomerates, metasandstones, and slates, followed by a thick package of gray to pink recrystallized limestones. ...
... The variably deformed and metamorphosed clastic rock assemblages known as "Eymir Unit" are widespread around the study area as a part of the Karakaya Complex. The Triassic-aged Eymir Unit is composed of greywacke and arkosic sandstone intercalated with shales (or their metamorphic equivalents) [23]. The Eymir unit metaclastics were intruded by diabase dikes with the back-arc basin signature [22]. ...
This study presented whole-rock elemental and Sr-Nd isotope geochemistry data with the purpose to decipher the origin and evolution of the Miocene Elmadağ Volcanic Complex, Central Anatolia (Ankara, Turkey). Volcanic products spanned in composition from mildly alkaline basaltic (47–52 wt% SiO2) and medium- to high-K calc-alkaline intermediate (54–62 wt% SiO2; andesite to trachyandesite) to felsic (64–74 wt% SiO2; dacite to rhyolite) units. Despite a homogeneous major element composition, basaltic rocks were characterized by two distinct trace element and isotopic signatures, which have been correlated with different mantle sources. The first group of basaltic rocks was similar to those of oceanic island basalts (OIB) and was derived from asthenospheric mantle source. The second group had geochemical characteristics of orogenic basalts derived from subduction-modified lithospheric mantle source and represented parental magma of the intermediate to felsic rocks. By coupling geochemical and textural analyses of the rocks from the Elmadağ Volcanic Complex, I suggest that crystallization of olivine + clinopyroxene + apatite played an important role in the evolution of basaltic rocks, while plagioclase + amphibole + apatite + Fe-Ti oxides ± zircon crystallization was major process involved in the evolution of intermediate to felsic rocks. The EVC basaltic rocks were associated with the post-collisional extensional tectonic regime in the Central Anatolia, but the coexistence of the OIB-like volcanism implies variations in the extension dynamics during Miocene.
... The latter contain blocks of Carboniferous and Permian neritic limestones, basalts, as well as Devonian to Triassic radiolarian cherts. This clearly indicates that Paleozoic oceanic crust (Paleotethys) was consumed during the early Mesozoic Mostler, 1994, Okay et al., 2011;Sayit et al., 2011). The blueschists and eclogites of the Sakarya unit are thought to have been exhumed in a subduction channel and show that deep oceanic underthrusting below the Sakarya unit has occurred either northward (Okay and Nikishin, 2015) or southward (Şengör and Yılmaz, 1981;Eyuboglu et al., 2018) below the Variscan parts of the Sakarya unit. ...
We present a map that correlates tectonic units between Alps and western Turkey accompanied by a text providing access to literature data, explaining the concepts used for defining the mapped tectonic units, and first-order paleogeographic inferences. Along-strike similarities and differences of the Alpine-Eastern Mediterranean orogenic system are discussed. The map allows (1) for superimposing additional information, such as e.g., post-tectonic sedimentary basins, manifestations of magmatic activity, onto a coherent tectonic framework and (2) for outlining the major features of the Alpine-Eastern Mediterranean orogen. Dinarides-Hellenides, Anatolides and Taurides are orogens of opposite subduction polarity and direction of major transport with respect to Alps and Carpathians, and polarity switches across the Mid-Hungarian fault zone. The Dinarides-Hellenides-Taurides (and Apennines) consist of nappes detached from the Greater Adriatic continental margin during Cretaceous and Cenozoic orogeny. Internal units form composite nappes that passively carry ophiolites obducted in the latest Jurassic–earliest Cretaceous or during the Late Cretaceous on top of the Greater Adriatic margin successions. The ophiolites on top of composite nappes do not represent oceanic sutures zones, but root in the suture zones of Neotethys that formed after obduction. Suturing between Greater Adria and the northern and eastern Neotethys margin occupied by the Tisza and Dacia mega-units and the Pontides occurred in the latest Cretaceous along the Sava-İzmir-Ankara-Erzincan suture zones. The Rhodopian orogen is interpreted as a deep-crustal nappe stack formed in tandem with the Carpatho-Balkanides fold-thrust belt, now exposed in a giant core complex exhumed in late Eocene to Miocene times from below the Carpatho-Balkan orogen and the Circum-Rhodope unit. Its tectonic position is similar to that of the Sakarya unit of the Pontides. We infer that the Rhodope nappe stack formed due to north-directed thrusting. Both Rhodopes and Pontides are suspected to preserve the westernmost relics of the suture zone of Paleotethys.
... The initial reconstruction (Ş eng€ or and Yilmaz, 1981) suggested that the Palaeotethyan ocean was located north of the Sakarya microplate (i.e., south of the Eurasian plate) and was closed by southward subduction(s) (Fig. 2a). G€ oncüo glu et al. (1997, 2000, 2010), Sayit et al. (2010Sayit et al. ( , 2011 and G€ oncüo glu (2009, 2013) proposed the same location but suggested that the Palaeotethyan Ocean was closed by two opposite dipping intra-oceanic subduction zones active at the end of the Triassic: a southward subduction beneath the Sakarya microplate, which created the Karakaya Complex (sensu Okay and G€ oncüo glu, 2004), and a northward one that generated a supra-subduction-type complex (i.e., Küre Complex; Kozur et al., 2000). Alternative models suggest that the Palaeotethys was located to the south of the Sakarya microplate and was closed by a southward subduction (Okay et al., 1996(Okay et al., , 2002(Okay et al., , 2006Okay and Tüysüz, 1999;Okay, 2000;Usta€ omer, 2011, 2012;Topüz et al., 2017) (Fig. 2b) or a northward subduction (Stampfli and Borel, 2002) (Fig. 2c). ...
... OIB: oceanic island basalt; BABB: back-arc basin basalt. m elanges of the Late Triassic age tectonically interleaved with Late Triassic fore-deep-type sediments (Sayit et al., 2011). The recent geographical distribution of the Karakaya Complex in the Sakarya terrane (Topüz et al., 2018), as well as the south-verging tectonic relations of the oceanic assemblages, indicates their derivation from north of the Sakarya terrane. ...
The Anatolian peninsula is a key location to study the central portion of the Neotethys Ocean(s) and to understand how its western and eastern branches were connected. One of the lesser known branches of the Mesozoic ocean(s) is preserved in the northern ophiolite suture zone exposed in Turkey, namely, the Intra-Pontide suture zone. It is located between the Sakarya terrane and the Eurasian margin (i.e., Istanbul-Zonguldak terrane) and consists of several metamorphic and non-metamorphic units containing ophiolites produced in supra-subduction settings from the Late Triassic to the Early Cretaceous. Ophiolites preserved in the metamorphic units recorded pervasive deformations and peak metamorphic conditions ranging from blueschist to eclogite facies. In the non-metamorphic units, the complete oceanic crust sequence is preserved in tectonic units or as olistoliths in sedi-mentary m elanges. Geochemical, structural, metamorphic and geochronological investigations performed on ophiolite-bearing units allowed the formulation of a new geodynamic model of the entire "life" of the Intra-Pontide oceanic basin(s). The reconstruction starts with the opening of the Intra-Pontide oceanic basins during the Late Triassic between the Sakarya and Istanbul-Zonguldak continental microplates and ends with its closure caused by two different subductions events that occurred during the upper Early Jurassic and Middle Jurassic. The continental collision between the Sakarya continental microplate and the Eurasian margin developed from the upper Early Cretaceous to the Palaeocene. The presented reconstruction is an alternative model to explain the complex and articulate geodynamic evolution that characterizes the southern margin of Eurasia during the Mesozoic era.
... A radiolarian assemblage similar to that obtained from the basal part of the Tavuscayiri section has been recovered from sample Kilek-23 in the Kilek section (e.g. Pseudohagiastrum cordevolicum (Kozur & (Kozur & Mostler 1972, 1978, 1979 and from Turkey (Tekin 1999;Tekin & Bedi 2007a, b;Tekin & G€ onc€ uoglu 2007;Varol et al. 2007;Dumitrica et al. 2010Dumitrica et al. , 2013aSayit et al. 2011Sayit et al. , 2015Tekin et al. 2012;Dumitrica 2017). The main part of the fauna correlates well with faunas obtained from the upper Lower Carnian (based on the two-fold Carnian subdivison) or middle Middle Carnian (based on the three-fold Carnian subdivison), indicating the Tetraporobrachia haeckeli Zone in previous studies (e.g. ...
The Mersin Mélange, located in southern Turkey north-west of the city of Mersin, includes blocks and tectonic slices of different origins. The Kilek section in the Mersin Mélange was sampled for a thorough examination of its lithology, biostratigraphy and fossil content. Two samples from the cherty limestone layers within the Huglu Tuffites at the top of the section yielded a rich silicified ostracod fauna of late Early Carnian (based on a two-fold Carnian subdivision) or middle Middle Carnian age (based on a three-fold Carnian subdivision), deposited in an open marine environment, in the outer platform-upper slope zone. We report 121 ostracod species belonging to 53 genera. Two new genera are described: Edithobairdia Forel gen. nov. and Gencella Forel gen. nov., as well as 16 new species: Acanthoscapha mersinella Forel sp. nov., Bairdia hugluensis Forel sp. nov., Acratia kollmanni Forel sp. nov., Citrella? carniana Forel sp. nov., Cytheropteron? schornikovi Forel sp. nov., Eucytherura lacerata Forel sp. nov., Gencella taurensis Forel sp. nov., Kerocythere dorsidenticulata Forel sp. nov., Kerocythere tricostata Forel sp. nov., Monoceratina praevulsaformis Forel sp. nov., Patellacythere tourkosella Forel sp. nov., Polycope kilekensis Forel sp. nov., Ptychobairdia praekristanae Forel sp. nov., Simeonella daginikella Forel sp. nov., Spinomicrocheilinella reliquiaella Forel sp. nov. and Triassocythere tavuscayiriensis Forel sp. nov. The diagnosis of Acratia goemoeryi Kozur is emended. The Kilek fauna retains primitive characteristics illustrated by the first known occurrence of Palaeocopida and Rectonariidae (typical Palaeozoic forms) in the Late Triassic, associated with typical Triassic–modern elements such as thick-shelled and ornamented Bairdiidae and diverse Cytheroidea known from the Middle and Late Triassic worldwide. The unique composition of Palaeozoic and Mesozoic taxa from the Kilek section illustrates unexpected long-term survival in a deep-sea refuge zone following the end-Permian extinction, and the diachronous character of the ostracod recovery in different environments.
http://zoobank.org/urn:lsid:zoobank.org.pub:662C3D5C–2B86–4D7B–BDB5–8F8B6A1AD1E7
