The Ortaköy-Barcın Plateau Cretaceous sequence is located in the Antalya nappes outcropping throughout the Akseki-Güzelsu-Köprülü which is in northern of the Gündoğmuş (Antalya). The sequence begins with Albian limestones containing mainly Pseudonummoloculina aurigerica, Praechrysalidina infracretacea, Nezzazata isabellae, Trochamminoides coronus, Glomospira urgoniana, Vercorsella arenata, Cuneolina parva and they are conformably overlain by the Cenomanian limestones including Sellialveolina viallii, Ovalveolina maccagnoae, Biplanata peneropliformis, Pseudorhapydionina dubia, Pseudolituonella sp., Biconcava bentori, Merlingina cretacea, Chrysalidina gradata, Cuneolina pavonia, Coxites zubairensis. The Albian-Cenomanian limestones that contain frequently breccia levels represent peritidal environments of restricted inner platform exposed to short-term subaerially. They are composed of dominantly fenestral/birdseye mudstone, fenestral/laminated peloidal packstone to grainstone, and foraminiferal wackestone. The Albian-Cenomanian inner platform sequence is disconformably overlain by the Maastrichtian limestones deposited in slope to basin, mainly containing Orbitoides media-megaloformis, Lepidorbitoides sp., Siderolites cf. S. calcitrapoides, Omphalocyclus sp. The Maastrichtian sequence is composed of bioclastic limestone and alternation of chert-bearing micritic limestone and calciturbidite. The bioclastic limestone and calciturbidite have the feature of bioclastic packstone to grainstone microfacies containing larger benthic foraminifera and the chert-bearing micritic limestones have the feature of pelagic wackestone microfacies including planktonic foraminifera. The data obtained reveal that the Maastrichtian slope to basin facies overlying the unconformity developed after a rapid subsidence of the platform due to tectonism.
A new representative of the genus Arenobulimina is described as Arenobulimina geyikensis n. sp. from the Aptian shallow-marine limestones of the Geyik Dagi area and Anamas Dag (Central Taurides, Turkey). Arenobulimina geyikensis n. sp. is characterized by a trochospiral evolute test with mostly three whorls, with generally five to six chambers per whorl, up to seven chambers in the last whorl, and a calcareous microgranular (without visible agglutinating grains), pseudokeriothecal (or canaliculate) wall. It differs from all species attributed to the genus Arenobulimina in the Lower Cretaceous in having a larger test with a relatively thick and pseudokeriothecal wall. It has so far been recorded from the Western Alps, France in open nomenclature and Arenobulimina geyikensis n. sp. is here considered as a stratigraphically important taxon for the Aptian platform carbonates in the peri-Mediterranean carbonate platforms.
The study area comprises southern non-metamorphic part of the Bolkar Mountains which are situated in southern Turkey, eastern part of the Central Taurides. The studied five outcrops form geologically parts of the tectonostratigraphic units called as allochthonous Aladag Unit and autochthonous Geyikdagi Unit. The aim of this study is to describe microfacies and depositional environments of the Bolkar Mountains Early Cretaceous shallow- water platform carbonates. The Lower Cretaceous is represented by continuous thick- bedded to massive dolomite sequence ranging from 100 to 150 meters thick, which only contains locally laminated limestone intercalations in the Yüğlük section and thick to very thick-bedded uniform limestones ranging from approximately 50 to 120 meters, consist of mainly laminated- fenestral mudstone, peloidal-intraclastic grainstone-packstone, bioclastic packstone- wackestone, benthic foraminiferal-intraclastic grainstone-packstone, ostracod-fenestral wackestone-mudstone, dasycladacean algal packstone-wackestone and ooidal grainstone microfacies. Based on a combination sedimantological data, facies/microfacies and micropaleontological (predominantly dasycladacean algae and diverse benthic foraminifera) analysis, it is concluded that Early Cretaceous platform carbonates of the Bolkar Mountains reflect a tidally affected tidal-flat and restricted lagoon settings. During the Berriasian- Valanginian unfavourable facies for benthic foraminifera and dolomitization were predominate. In the Hauterivian-early Aptian, the effect of dolomitization largely disappeared and inner platform conditions still prevailed showing alternations of peritidal and lagoon facies, going from peritidal plains (representing various sub-environments including supratidal, intertidal area, tidal-intertidal ponds and ooid bars) dominated by ostracod and miliolids, to dasycladacean algae-rich restricted lagoons-subtidal. These environments show a transition in the vertical and lateral directions in all studied stratigraphic sections.
Abstract Phenacophragma oezeri n. sp. (phylum Foraminifera, family Mayncinidae) is described from the Albian shallow-marine limestones of the Geyik Daği area, Central Taurides, S Turkey. It is characterized by a lenticular, completely involute test with eight to nine wedge-shaped chambers in the last whorl rapidly increased in height and by an areal and small slit-like aperture. It occurs in benthic foraminiferal wackestone/packstone and grainstone microfacies with gastropods, rudists and dasycladalean algae, in association with mainly Protochrysalidina elongata, Pseudonummoloculina aurigerica, Pseudonummoloculina heimi, Mayncina bulgarica, Mesorbitolina gr. texana, Cuneolina sliteri, Cuneolina parva, Akcaya minuta, and Akcaya auruncensis. This new species differs from the type species Phenacophragma assurgens in having a completely involute and lenticular test with less numerous chambers in the last whorl. It can be distinguished from the accompanied Mayncina bulgarica by its more axially compressed lenticular shape and its wedge-shaped (rather than falciform) chambers.
