Benthic Foraminifera of the Upper Jurassic Platform Carbonate Sequence in the Aydincik (Içel) Area, Central Taurides, S Turkey

The Upper Jurassic sequence of the Aydincik (Içel) area consists of platform limestones which were deposited in a subtidal, restricted lagoon environment. Stratigraphic distribution of benthic foraminifera and calcareous algae, examined in thin-sections, is shown in a range-chart. The microfossil assemblage indicates the Salpingoporella sellii subzone of the Kurnubia palastiniensis cenozone, corresponding approximately to the lower part of the Malm. Some benthic foraminifera with considerable stratigraphic value within the Mesozoic Tethys are described. Among the benthic foraminifera, taxa of the family Pfenderinidae, especially the subfamily Kurnubiinae, are dominant and frequent throughout the sequence. The planispirally coiled taxa are represented by the families Nautiloculinidae, Charentiidae and Cyclamminidae (subfamily Bucciccrenatinae)

Late Cretaceous-Early Eocene tectonic development of the Tethyan suture zone in the Erzincan area, Eastern Pontides, Turkey

Six individual tectonostratigraphic units are identified within the Izmir-Ankara-Erzincan Suture Zone in the critical Erzincan area of the Eastern Pontides. The Ayikayasi Formation of Campanian-Maastrichtian age is composed of bedded pelagic limestones intercalated with polymict, massive conglomerates. The Ayikayasi Formation conformably overlies the Tauride passive margin sequence in the Munzur Mountains to the south and is interpreted as an underfilled foredeep basin. The Refahiye Complex, of possible Late Cretaceous age, is a partial ophiolite composed of similar to 75 % (by volume) serpentinized peridotite (mainly harzburgite), similar to 20 % diabase and minor amounts of gabbro and plagiogranite. The complex is interpreted as oceanic lithosphere that formed by spreading above a subduction zone. Unusual screens of metamorphic rocks (e.g. marble and schist) locally Occur between sheeted diabase dykes. The Upper Cretaceous Karayaprak Melange exhibits two lithological associations: (1) the basalt + radiolarite + serpentinite association, including depleted arc-type basalts; (2) the massive neritic limestone + lava + volcaniclastic association that includes fractionated, intermediate-composition lavas, and is interpreted as accreted Neotethyan seamount(s). The several-kilometre-thick Karadag Formation, of Campanian-Maastrichtian age, is composed of greenschist-facies volcanogenic rocks of mainly basaltic to andesitic composition, and is interpreted as an emplaced Upper Cretaceous volcanic arc. The Campanian-Early Eocene Sutpinar Formation (similar to 1500 m thick) is a coarsening-Upward succession of turbiditic calcarenite, sandstone, laminated mudrock, volcaniclastic sedimentary rocks that includes rare andesitic lava, and is interpreted as a regressive forearc basin. The Late Paleocene-Eocene Sipikor Formation is a laterally varied succession of shallow-marine carbonate and siliciclastic lithofacies that overlies deformed Upper Cretaceous units with an angular unconformity. Structural study indicates that the assembled accretionary prism, supra-subduction zone-type oceanic lithosphere and volcanic are units were emplaced northwards onto the Eurasian margin and also southwards onto the Tauride (Gondwana-related) margin during Campanian-Maastrichtian time. Further, mainly southward thrusting took place during the Eocene in this area, related to final closure of Tethys. Our preferred tectonic model involves northward subduction, supra-subduction zone ophiolite genesis and arc magmatism near the northerly, Eurasian margin of the Mesozoic Tethys

The Misis-Andirin complex: a mid-tertiary melange related to late-stage subduction of the southern Neotethys in S Turkey

WOS: 000220276800003The Mid-Tertiary (Mid-Eocene to earliest Miocene) Misis-Andirin Complex documents tectonic-sedimentary processes affecting the northerly, active margin of the South Tethys (Neotethys) in the easternmost Mediterranean region. Each of three orogenic segments, Misis (in the SW), Andirin (central) and Engizek (in the NE) represent parts of an originally continuous active continental margin. A structurally lower Volcanic-Sedimentary Unit includes Late Cretaceous arc-related extrusives and their Lower Tertiary pelagic cover. This unit is interpreted as an Early Tertiary remnant of the Mesozoic South Tethys. The overlying melange unit is dominated by tectonically brecciated blocks (> 100 in across) of Mesozoic neritic limestone that were derived from the Tauride carbonate platform to the north, together with accreted ophiolitic material. The melange matrix comprises polymict debris flows, high- to low-density turbidites and minor hemipelagic sediments. The Misis-Andirin Complex is interpreted as an accretionary prism related to the latest stages of northward subduction of the South Tethys and diachronous continental collision of the Tauride (Eurasian) and Arabian (African) plates during Mid-Eocene to earliest Miocene time. Slivers of Upper Cretaceous oceanic crust and its Early Tertiary pelagic cover were accreted, while blocks of Mesozoic platform carbonates slid from the overriding plate. Tectonic mixing and sedimentary recycling took place within a trench. Subduction culminated in large-scale collapse of the overriding (northern) margin and foundering of vast blocks of neritic carbonate into the trench. A possible cause was rapid roll back of dense downgoing Mesozoic oceanic crust, such that the accretionary wedge taper was extended leading to gravity collapse. Melange formation was terminated by underthrusting of the Arabian plate from the south during earliest Miocene time. Collision was diachronous. In the east (Engizek Range and SE Anatolia) collision generated a Lower Miocene flexural basin infilled with turbidites and a flexural bulge to the south. Miocene turbiditic sediments also covered the former accretionary prism. Further west (Misis Range) the easternmost Mediterranean remained in a pre-collisional setting with northward underthrusting (incipient subduction) along the Cyprus arc. The Lower Miocene basins to the north (Misis and Adana) indicate an extensional (to transtensional) setting. The NE-SW linking segment (Andirin) probably originated as a Mesozoic palaeogeographic offset of the Tauride margin. This was reactivated by strikeslip (and transtension) during Later Tertiary diachronous collision. Related to on-going plate convergence the former accretionary wedge (upper plate) was thrust over the Lower Miocene turbiditic basins in Mid-Late Miocene time. The Plio-Quaternary was dominated by left-lateral strike-slip along the East Anatolian transform fault and also along fault strands cutting the Misis-Andirin Complex. (C) 2003 Elsevier Ltd. All rights reserved

The Misis-Andi?ri?n Complex: A Mid-Tertiary melange related to late-stage subduction of the Southern Neotethys in S Turkey

The Mid-Tertiary (Mid-Eocene to earliest Miocene) Misis-Andrn Complex documents tectonic-sedimentary processes affecting the northerly, active margin of the South Tethys (Neotethys) in the easternmost Mediterranean region. Each of three orogenic segments, Misis (in the SW), Andrn (central) and Engizek (in the NE) represent parts of an originally continuous active continental margin. A structurally lower Volcanic-Sedimentary Unit includes Late Cretaceous arc-related extrusives and their Lower Tertiary pelagic cover. This unit is interpreted as an Early Tertiary remnant of the Mesozoic South Tethys. The overlying melange unit is dominated by tectonically brecciated blocks (>100 m across) of Mesozoic neritic limestone that were derived from the Tauride carbonate platform to the north, together with accreted ophiolitic material. The melange matrix comprises polymict debris flows, high- to low-density turbidites and minor hemipelagic sediments.The Misis-Andrn Complex is interpreted as an accretionary prism related to the latest stages of northward subduction of the South Tethys and diachronous continental collision of the Tauride (Eurasian) and Arabian (African) plates during Mid-Eocene to earliest Miocene time. Slivers of Upper Cretaceous oceanic crust and its Early Tertiary pelagic cover were accreted, while blocks of Mesozoic platform carbonates slid from the overriding plate. Tectonic mixing and sedimentary recycling took place within a trench. Subduction culminated in large-scale collapse of the overriding (northern) margin and foundering of vast blocks of neritic carbonate into the trench. A possible cause was rapid roll back of dense downgoing Mesozoic oceanic crust, such that the accretionary wedge taper was extended leading to gravity collapse. Melange formation was terminated by underthrusting of the Arabian plate from the south during earliest Miocene time. Collision was diachronous. In the east (Engizek Range and SE Anatolia) collision generated a Lower Miocene flexural basin infilled with turbidites and a flexural bulge to the south. Miocene turbiditic sediments also covered the former accretionary prism. Further west (Misis Range) the easternmost Mediterranean remained in a pre-collisional setting with northward underthrusting (incipient subduction) along the Cyprus arc. The Lower Miocene basins to the north (Misis and Adana) indicate an extensional (to transtensional) setting. The NE-SW linking segment (Andrn) probably originated as a Mesozoic palaeogeographic offset of the Tauride margin. This was reactivated by strike-slip (and transtension) during Later Tertiary diachronous collision. Related to on-going plate convergence the former accretionary wedge (upper plate) was thrust over the Lower Miocene turbiditic basins in Mid-Late Miocene time. The Plio-Quaternary was dominated by left-lateral strike-slip along the East Anatolian transform fault and also along fault strands cutting the Misis-Andrn Complex. © 2003 Elsevier Ltd. All rights reserved

Tectonostratigraphic evolution of the upper cretaceous-cenozoic central anatolian basins: An integrated study of diachronous ocean basin closure and continental collision

The Upper Cretaceous-Mid-Eocene Kirikkale, Tuz Gölü, Haymana and ç ankiri basins are bounded by the Pontide (Eurasian) continental margin to the north, the Nig`de-Kirşehir microcontinent to the east and the Tauride-Anatolide continental unit to the south. The basins developed during northward subduction/collision of theÌzmir-Ankara-Erzincan Ocean ('northern Neotethys') in the north and the inferred Inner Tauride Ocean in the south. Subduction of the Ìzmir-Ankara-Erzincan Ocean resulted in latest Cretaceous collisionof the Nig`de-Kirşehir microcontinent with the Pontide active margin and ophiolite emplacement. Some mid-ocean ridge-type oceanic crust remained to the SW and formed the basement of the Kirikkale and Tuz Gölü basins. These basins are partially floored by an accretionary wedge to the west and by the Nig`de-Kirşehir microcontinent to the east. Locally volcaniclastic, the sediment infill switched to terrigenous after latest Cretaceous. The Haymana Basin, further NW, developed as a forearc basin on the Mesozoic accretionary wedge and Pontide continental fragments. The çankiri Basin also developed on an accretionary wedge, bounded by the Eurasian active margin to the north. An extensional setting prevailed during the latest Cretaceous related to subduction of remnant oceanic crust, followed by a switch to regional compression during Late Paleocene-Mid Eocene progressive and diachronous collision. © The Geological Society of London 2013

Cenomanian-Turonian drowning of the Arabian Carbonate Platform, the Inisdere section, Adiyaman, SE Turkey

The Cenomanian-Turonian carbonate ramp in the Adiyaman Region of SE Turkey (Northern Arabian Platform) records an abrupt shift from benthic carbonate deposits to pelagic deposits near the Cenomanian-Turonian boundary event (CTBE) in the Inisdere stratigraphic section and surrounding borehole sections. A positive delta C-13 excursion of up to 2.15% is recorded in carbonate and organic carbon deposited around the CTBE and provides evidence of a direct link between the CTBE and oceanic anoxic events and the demise of the shallow carbonate production in the Derdere Formation. The microfacies analyses, biostratigraphic dating and palaeoenvironmental interpretations suggest that the platform was drowned near the CTBE as a result of changing environmental conditions. The microfacies indicating significant deepening show a contemporaneity to equivalent surfaces globally and thus strongly support an isochronous formation of Cenomanian-Turonian facies by eustatic sea-level changes. Anoxia spreading over the platform drastically reduced the carbonate production as observed in the studied sections and, therefore, resulted in a reduction in carbonate accumulation rates. Regional/local subsidence and a coeval sea-level rise during the late Cenomanian to early Turonian interval were the cause of the drowning of the platform, including regional anoxia at the northern Arabian platform linked to the Cenomanian-Turonian oceanic anoxic event (OAE2)

Cenomanian–Turonian drowning of the Arabian Carbonate Platform, the İnişdere section, Adıyaman, SE Turkey

The Cenomanian-Turonian carbonate ramp in the Adiyaman Region of SE Turkey (Northern Arabian Platform) records an abrupt shift from benthic carbonate deposits to pelagic deposits near the Cenomanian-Turonian boundary event (CTBE) in the Inisdere stratigraphic section and surrounding borehole sections. A positive delta C-13 excursion of up to 2.15% is recorded in carbonate and organic carbon deposited around the CTBE and provides evidence of a direct link between the CTBE and oceanic anoxic events and the demise of the shallow carbonate production in the Derdere Formation. The microfacies analyses, biostratigraphic dating and palaeoenvironmental interpretations suggest that the platform was drowned near the CTBE as a result of changing environmental conditions. The microfacies indicating significant deepening show a contemporaneity to equivalent surfaces globally and thus strongly support an isochronous formation of Cenomanian-Turonian facies by eustatic sea-level changes. Anoxia spreading over the platform drastically reduced the carbonate production as observed in the studied sections and, therefore, resulted in a reduction in carbonate accumulation rates. Regional/local subsidence and a coeval sea-level rise during the late Cenomanian to early Turonian interval were the cause of the drowning of the platform, including regional anoxia at the northern Arabian platform linked to the Cenomanian-Turonian oceanic anoxic event (OAE2)

Late Cretaceous-Miocene sedimentary development of the Arabian continental margin in SE Turkey (Adiyaman region): Implications for regional palaeogeography and the closure history of Southern Neotethys

The Middle Cretaceous-Late Miocene sedimentary successions that are exposed on the Arabian continental margin (near Adiyaman) provide valuable insights into sedimentary, tectonic and climatic processes that affected the Southern Neotethys and its continental margins. Deposition in the region began with Aptian-Early Campanian shelf carbonates, followed by deepening during the Mid-Campanian. Lithoclastic-bioclastic turbidites accumulated along the downfaulted northern margin of the Arabian platform during the Campanian. A flexurally controlled foredeep developed in advance of the emplacement of Mesozoic allochthonous continental margin and oceanic rocks during the latest Campanian-Early Maastrichtian (e.g. supra-subduction zone Koçali ophiolite). Alluvial detritus was shed from the emplaced allochthon in non-marine to shallow-marine deltaic settings during latest Campanian-Early Maastrichtian. A marine transgression resulted in the establishment of a shallow-marine shelf during the mid-Maastrichtian. During the latest Maastrichtian, the platform submerged, initiating deeper-water hemipelagic sedimentation. Uplift took place during the Palaeocene resulting in sediment instability, slumping and formation of high-density, subaqueous gravity flows. In response to regional faulting and tilting, some areas in the north and the southwest emerged during the Early-Middle Eocene generating alluvial fans in a warm, humid climate that favoured oxidation and reddening. The likely control of the tectonic instability was far-field compression related to the latest stages of subduction of the Southern Neotethys or the initial stages of collision of the Arabian and Tauride continents. An Oligocene hiatus is likely to reflect the formation of a collision-related forebulge, followed by flexural subsidence to form an Early Miocene foreland basin. This was finally over-ridden by the northerly, active continental margin of the Southern Neotethys during Early-Mid Miocene. Regional suture tightening (Mid-Late Miocene) and related non-marine coarse clastic sedimentation was followed by westward 'tectonic escape' of the Anatolian microplate towards the Aegean region during Plio-Quaternary time. © 2015