13 research outputs found
Evidence from the Kyrenia Range, Cyprus, of the northerly active margin of the Southern Neotethys during Late Cretaceous–Early Cenozoic time
Pseudomarssonella REDMOND 1965 (Foraminifera) and related taxa from the Jurassic platform carbonate succession of the Central Taurides, S Turkey: its phylogenetic relation with the subfamily Paleopfenderininae
Pseudomarssonella and related taxa have been recorded in the upper part of the Redmondoides lugeoni/Redmondoides cf. rotundatus Zone, Paleopfenderina trochoidea-salernitana and Kurnubia ex. gr. palastiniensis zones, and the lower half of the Clypeina jurassica Zone, from the Bathonian to the lower Tithonian of the Central Taurides (S Turkey) inner platform carbonate succession. A tentative phylogenetic tree of the Jurassic pfenderinids (paleopfenderins) is given in this study. The Paleopfenderininae are suggested to have evolved from Pseudomarssonella REDMOND 1965 which might have diverged from Redmondoides BANNER et al. 1991 or Riyadhella REDMOND 1965. This evolution was carried out during the early Bathonian by the acquisition of accessory, cribrate apertural plate and more numbers of chambers per whorl. Pseudomarssonella has been removed from the family Chrysalidinidae (subfamily Paravalvulininae) since it is phylogenetically and taxonomically separated from Paravalvulina, which is fundamentally triserial, has cribrate septal flap as a prolongation of septum and has no secondary infillings. Herein it is placed into the family Pfenderinidae, subfamily Paleopfenderininae
Stratigraphy and depositional history of the Cretaceous carbonate successions in the Spil Mountain (Manisa, W Turkey)
© 2014 Elsevier Ltd.The Bornova Flysch Zone (western Turkey) consists of huge Mesozoic limestone and ophiolite blocks embedded into sheared siliciclastic sedimentary rocks of Maastrichtian-Paleocene age. The limestone blocks, which range in age from Late Triassic to Cretaceous, are considered to be olistoliths or deformed and sliced platform parts. In the Spil Mountain, two successions of Cretaceous carbonates are tectonostratigraphically differentiated: (1) a Lower Cretaceous and Campanian(?)-Maastrichtian relatively autochthonous succession showing sedimentary transition to the Bornova Flysch, and (2) a Cenomanian(?)-lower Campanian allochthonous succession overthrusted to the flysch. These successions represent separate parts of the same platform. The autochthonous succession bears Lower Cretaceous peritidal carbonates at its base and is named Unit 1. The succession is often composed of fenestral mudstone and algal wackestone microfacies. Unit 2 disconformably overlies Unit 1 and consists of platform-derived litho and bioclastic packstones of Campanian(?)-Maastrichtian age. This unit reveals a typical thinning and fining upward sequence, finally passing into pelagic wackestones of Unit 3. The two aforementioned units record a platform drowning event, which occurred rapidly based on the presence of planktonic foraminifera within matrix of basal breccia. Carbonate deposition ceased due to the input of siliciclastic sediments during the late Maastrichtian-Paleocene. The allochthonous succession consists of two vertically superimposed units: (1) Cenomanian(?)-Santonian rudistid limestones (Unit 4) deposited in restricted platform environments and (2) Santonian-lower Campanian pelagic limestones (Unit 5) indicating open platform to slope conditions. The Spil Mountain Cretaceous carbonate sequences are correlated with those in peri-Mediterranean platforms. They show close similarities to the Bey Dağlari (western Taurides) carbonate sequences in stratigraphy and facies. Paleontological and sedimentological analyses and the microfacies enable us to reconstruct a paleoenvironment evolution and a facies model for the Spil Mountain carbonate deposits during the Cretaceous period
Stratigraphy and Microfacies of Cretaceous Limestones in the Bornova Flysch Zone (Spil Mountain, Manisa, Western Turkey)
Spil Mountain (Manisa, western Turkey) is situated in the Bornova Flysch Zone, which is bounded by the Izmir-Ankara Suture Zone (northern branch of Neo-Tethys) to the northwest and by the Menderes Massif to the southeast. The purpose of this study is to describe microfacies and microfossil assemblages of the Spil Mountain carbonate sequences. Two carbonate sequences in autochthonous and allochthonous settings are differentiated. The autochthonous sequence begins with inner-platform carbonates of Early Cretaceous age, which are represented by algal wackestone, fenestral mudstone, intraclastic packstone with Praechrysalidina infracretacea, Salpingoporella annulata, and charophyte oogonia. The platform succession is disconformably overlain by calciclastic turbidites and pelagic wackestones of Maastrichtian age, representing platform drowning, and then passes upward into siliciclastic sediments containing large limestone blocks. Allochthonous carbonate sequences range in age from the ? Cenomanian to Santonian-early Campanian, and were deposited in peritidal to outer-shelf palaeoenvironments. The lower part of the allochthonous sequence is composed of foraminiferal-intraclastic wackestones-packstones with mainly miliolids and Cuneolina pavonia. The middle part consists of peloidal wackestone/packstone with Aeolisaccus, Thaumatoporella, benthic foraminifers, and rudist shell fragments. The benthic foraminifera are represented by Pseudocyclammina sphaeroidea, Keramosphaerina tergestina, Moncharmontia apenninica/compressa, and Scandonea samnitica. In the upper part of the allochthonous sequence, pelagic wackestone with Marginotruncana and Dicarinella is alternated with foraminiferal-peloidal packstone with rudist shell fragments and microbioclastic wackestone
Benthonic Foraminiferal Biostratigraphy of the Upper Cretaceous (Middle Cenomanian-Coniacian) Sequences of the Bey Daglari Carbonate Platform, Western Taurides, Turkey
Identification of the benthonic foraminiferal assemblages from ten stratigraphic sections from the inner platform limestones of the Middle Cenomanian-Coniacian successions of the Bey Daglari carbonate platform (BDCP) allowed the recognition of one biozone and two subzones. The lower part of the platform limestones (Middle-Upper Cenomanian) is represented by relatively rich benthonic foraminiferal assemblages, while the upper part (Turonian-Coniacian) contains poor assemblages. The benthonic foraminiferal assemblages determined in the BDCP are dominated by long-ranging species. The shorter-ranging, stratigraphical index species have been selected to date the Upper Cretaceous platform limestones of the BDCP based on the distributions of the species in the circum-Mediterranean region. The Pseudolituonella reicheli-Pseudorhapydionina dubia Concurrent Range Zone is defined from the Middle-Upper Cenomanian platform limestones. The biozone includes the Cisalveolina lehneri Subzone and the Coxites zubairensis Subzone of Middle Cenomanian and Upper Cenomanian age respectively. The first occurrences of Moncharmontia apenninica-compressa and Pseudocyclammina sphaeroidea indicate the Late Turonian and the Coniacian respectively
The Madenli (Central Taurides) Upper Cretaceous platform carbonate succession: Benthic foraminiferal biostratigraphy and platform evolution
The Upper Cretaceous succession in the Madenli area (western Central Taurides, Southern Turkey) consists of platform carbonate rocks deposited in entirely peritidal environments, which are sensitive to sea level changes driven by global eustasy, but also strongly affected by local and regional tectonics. It includes economically important bauxite deposits. Previous works suggest different ages for bauxite formation ranging from the Albian to the Santonian. Benthic foraminiferal biostratigraphy and facies analysis of the Madenli and Dogankuzu outcrop sections allow for a more precise dating of the platform emersion periods. The footwall limestones of the bauxite deposits consist of well-bedded limestones (Unit-1), which contain a benthic foraminiferal assemblage (BFA) including mainly Biconcava bentori and Pastrikella biplana, Chrysalidina gradata (BFA I), assigned to the middle-upper Cenomanian. In the Madenli section, the first bauxite deposit occurs in the upper part of Unit-1 as a layer interbedded with pinkish sparitic and dolomitic beds (subunit-1a) deposited in supratidal environment. Subunit-1a is stratigraphically equivalent to the Dogankuzu and Mortal bauxite deposits considered as karst-related, unconformity-type deposits. The hanging-wall limestones of the bauxite are represented by the massive limestones (Unit-2) starting locally with either the upper Cenomanian characterized mainly by the presence of Pseudolituonella reicheli or upper Campanian comprising mainly Murciella cuvillieri and Moncharmontia apenninica (BFA II). There is no field evidence of a discontinuity surface at the contact between the lower part of Unit-2, including BFA I, and the upper part of Unit-2, including BFA II. This contact is defined as a paraconformity indicating a stratigraphic gap from the Turonian to the early Campanian. The top of Unit-2 is truncated by another discontinuity surface associated with a minor bauxite deposit. The overlying Unit-3 is characterized by well-bedded, rudist-bearing limestones topped by laminated and dolomitized limestones organized in shallowing upward cycles. It is assigned to the upper Maastrichtian based on the presence of Rhapydionina liburnica (BFA III) and rudist assemblage. A third emersion period of the platform corresponds to the early Maastrichtian. (C) 2018 Elsevier Masson SAS. All rights reserved
Late Cretaceous to Late Eocene Hekimhan Basin (Central Eastern Turkey) as a supra-ophiolite sedimentary/magmatic basin related to the later stages of closure of Neotethys
AbstractThe Hekimhan Basin is here put forward as a type example of a globally important class of basin, known as a supra-ophiolite basin. Such basins form after the emplacement of ophiolitic (i.e. oceanic) rocks onto a passive continental margin, but long prior to continental collision. The Hekimhan Basin developed as part of the northern margin of the Tauride microcontinent during the collision and suturing of two Neotethyan oceans to the north, namely the Inner Tauride Ocean and the İzmir–Ankara–Erzincan ocean. The basin records two main stages of tectonic development, during latest Cretaceous to Late Eocene time. The first phase of basin development during the Late Cretaceous (Maastrichtian) began with the erosion of emplaced ophiolitic rocks, resulting in non-marine clastic sedimentation. Subsequently, the basin rapidly subsided, in response to inferred regional crustal extension, resulting in the deposition of hemipelagic marls and local sapropelic mudstones. The axial parts of the basin experienced alkaline, within-plate-type, basaltic volcanism. The Late Maastrichtian culminated in deposition of shallow-marine carbonates. Overlying Paleocene sediments are restricted to thin, localised, marine evaporates, associated with a low-angle unconformity. The second stage of basin development began during the Early Eocene with deposition of shallow-marine carbonates, coupled with localised basaltic volcanism, again of extensional type. The basin emerged during the Mid–Late Eocene in a late-stage collisional to post-collisional setting. Compressional deformation largely reflects post-suture tightening. A short-lived marine transgression occurred during the Mid-Miocene. The basin was later deformed by both left-lateral and right-lateral strike-slip.Several different tectonic models are considered, notably extension related to the northward pull of a still-subducting oceanic slab, and back-arc extension related to northward subduction of Neotethys (to the south). The first alternative is consistent with the development of adjacent supra-ophiolite basins (e.g. Ülükışla and Darende Basins), and also with supra-ophiolite basins elsewhere (e.g. SE Turkey; Balkans; Oman)
A Cenomanian-Santonian rudist-bearing carbonate platform on the northern Arabian Plate, Turkey: facies and sequence stratigraphy
Recent studies have shown that Cenomanian-Santonian carbonate sedimentary rocks rich in rudists are widespread throughout southeastern Turkey. The Derdere and Karababa formations have been analysed in the Sabunsuyu section (Kilis Province). On a field scale, we can distinguish rudist-rich beds that rhythmically alternate with bioclastic levels composed of bivalves, gastropods and roveacrinids in these formations. Although pelagic faunal elements (predominantly planktic foraminifera and pithonellids) are documented in the lowermost part of the series, the rudist-rich facies are represented mainly in the Derdere and Karababa formations. Rudists, benthic and planktic foraminifera indicate middleelate Cenomanian and Turonian-Santonian ages for the Derdere and Karababa formations, respectively. Based on studied facies, five microfacies have been recognised and categorised in three facies groups: inner ramp, mid ramp and outer ramp. Evidence such as gradual changes in facies and absence of extensive uninterrupted barrier reefs indicate that the Derdere Formation was deposited in a ramp depositional system. The sedimentology and taphonomic signature of the rudist shell beds have been described in order to obtain a better understanding of the depositional environment and the physical processes that controlled Cenomanian-Santonian sedimentation. Monospecific tabular beds characterise mainly the upper part of the series (topmost part of Derdere Formation and Karababa Formation); more complex rudist concentrations, characterised by moderate species diversity, increase upsection. The rudist levels are associated with highstand systems tract deposits because of the suitability of trophic conditions in the rudist-dominated ramp
Late Palaeozoic-Neogene sedimentary and tectonic development of the Tauride continent and adjacent Tethyan ocean basins in eastern Turkey: New data and integrated interpretation
The eastern Taurus exemplifies continental rifting, passive margin development, Late Cretaceous melange genesis and ophiolite emplacement. Following Triassic rifting, a carbonate platform developed near sea level in the south (Munzur unit), whereas its northern extension (Neritic-pelagic unit) subsided into deep water during Late Jurassic-Late Cretaceous. Triassic-Cretaceous deep-water sediments and volcanics restore as distal deep-water slope/base of slope units. Jurassic-Cretaceous basic volcanics, interbedded with pelagic sediments, represent emplaced oceanic seamounts. Supra-subduction zone ophiolites formed to the north (c. 93 Ma), probably within an Inner Tauride ocean, and were emplaced southwards by trench-margin collision during latest Cretaceous (c. 75-66 Ma). The margin underwent flexural uplift/erosion and then subsidence/foredeep-infill. Part of the Tauride continent in the south (Malatya Metamorphics) deeply underthrust/subducted northwards, then exhumed rapidly by the late Maastrichtian (c. 65 Ma). To the south, oceanic lithosphere (e.g. Go center dot ksun ophiolite) was thrust northward beneath Tauride (Malatya) crust from a more southerly oceanic basin (Berit ocean), and intruded by Late Cretaceous subduction-related granitic rocks (88-82 Ma). Allochthonous units were assembled during the latest Cretaceous, followed by thick-skinned folding/thrusting, generally southwards, related to regional collision tectonics during Mid-Late Eocene. Part of the unmetamorphosed Tauride platform and its overriding Late Cretaceous allochthon were apparently displaced >60 km northeastwards. Mid-Late Miocene regional collision drove variable folding and re-thrusting, in places northwards. Regional comparisons suggest that the Tauride carbonate platform (Geyik Dag) narrowed eastwards, such that the palaeogeography of the E Taurides differed from farther west, influencing the late Mesozoic-Cenozoic structural development
REE Characteristics of Lower Cretaceous Limestone Succession in Gumushane, NE Turkey: Implications for Ocean Paleoredox Conditions and Diagenetic Alteration
TASLI, KEMAL/0000-0003-0160-6912; Al-Aasm, Ihsan/0000-0003-2166-0561; Hollis, Cathy/0000-0002-3980-2583WOS: 000565595400001Trace and rare earth elements (REEs) are considered to be reliable indicators of chemical processes for the evolution of carbonate systems. One of the best examples of ancient carbonate successions (Berdiga Formation) is widely exposed in NE Turkey. the Lower Cretaceous limestone succession of Berdiga Formation may provide a case study that reveals the effect of ocean paleoredox conditions on diagenetic alteration. Measurement of major, trace and REEs was carried out on the Lower Cretaceous limestones of the Berdiga Formation, to reveal proxies for paleoredox conditions and early diagenetic controls on their geochemistry. Studied micritic limestone microfacies (MF-1 to MF-3) indicate deposition in the inner platform to a deep shelf or continental slope paleoenvironment during the Hauterivian-Albian. the studied limestone samples mainly exhibit low Mg-calcite characteristics with the general chemical formula of Ca98.35-99.34Mg0.66-1.65(CO3). They are mostly represented by a diagnostic REE seawater signature including (1) slight LREE depletion relative to the HREEs (ave. 0.72 of Nd/Yb(N)and ave. 0.73 of Pr/Yb-N), (2) negative Ce anomalies (Ce/Ce* = 0.38-0.81; ave. 0.57), (3) positive La anomaly (La/La* = 0.21-3.02; ave. 1.75) and (4) superchondritic Y/Ho (ave. 46.26). Studied micritic limestones have predominantly low Hf (bdl to 0.5 mu g/g), Sc (bdl to 2 mu g/g) Th (bdl to 0.9 mu g/g) contents suggesting negligible to minor shale contamination. These findings imply that micritic limestones faithfully record chemical signals of their parental and diagenetic fluids. the succession also exhibits high ratios of Eu/Eu* (1.01-1.65; ave. 1.29 corresponding to the positive Eu anomalies), Sm/Yb (1.26-2.74; ave. 1.68) and La/Yb ratios (0.68-1.35; ave. 0.9) compared to modern seawater and wide range of Y/Ho ratios (29.33-70.00; ave. 46.26) which are between seawater and hydrogenetic Fe-Mn crusts. Several lines of geochemical evidence suggest water-rock interaction between parental seawater and basaltic rocks at elevated temperatures triggered by hydrothermal activity associated with Early Cretaceous basaltic magma generation. the range of Ce/Ce* values is suggestive of mostly oxic to dysoxic paleoceanographic conditions, with a sudden change to dysoxic conditions (Ce/Ce* = 0.71-0.81), in the uppermost part of the MF-1. This is followed by an abrupt deepening paleoenvironment with a relative increase in the oxic state of the seawater and deposition of deeper water sediments (MF-2 and MF-3) above a sharp transition. the differences in microfacies characteristics and foraminifera assemblage between MF-1 and overlying facies (MF-2 and MF-3) may also confirm the change in paleoceanographic conditions. Therefore, REEs data obtained from studied limestones have the potential to contribute important information as to regional paleoceanographic conditions of Tethys during an important period in Earth history.Scientific and Technological Research Council of Turkey (TUBITAK-CAYDAG)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [115Y005]; Karadeniz Technical University, Turkey (KTU BAP) [FBA-2015-5160, 7341-FBA-2018-7341]Funding for this study partly originated from Scientific and Technological Research Council of Turkey (TUBITAK-CAYDAG, Project no: 115Y005) and Karadeniz Technical University, Turkey (KTU BAP, Project no: FBA-2015-5160; and 7341-FBA-2018-7341)