Planktonic foraminiferal diversity and abundance changes across cretaceous-paleogene boundary beds in the Haymana basin and new observations on the extinction horizon

Karabeyoğlu, Ali Uygar
Abundance and diversity patterns in planktonic foraminifera are important for paleoenvironmental and paleoclimatic interpretations before and after the CretaceousPaleogene mass extinction. A 14,53 m thick section was measured crossing the boundary between the Haymana Formation and the Yeşilyurt Formation in the northern part of the Haymana Basin. In the last 3.75 meters of the Maastrichtian below the K-Pg boundary, a series of quantitative analyses were carried out on planktonic foraminifera found above 63 and 150-micron screen sizes. By using foraminiferal bioevents, biozones were established which are: Plummerita hantkeninoides Zone for the uppermost Maastrichtian; P0 and Parvularugoglobigerina eugubina zones for the base ofthe Danian. Additionally, paleobathymetry of the measured section was studied with the help of planktonic-benthic ratios. Calculations indicate approximately 400 m water depth for the depositional environment. Identification of deep water dweller planktonic foraminifers in the studied section, such as Planoglobulina multicamerata and Gublerina cuvillieri also supports this result. Quantitative analyses resulted that at the end of Maastrichtian, Heterohelix species, which are tolerant to temperature, nutrient, oxygen and salinity fluctuations, dominated (~40%) the environment while those which are not resilient such as Globotruncana species remained low (~10%). On the other hand, Guembelitria cretacea, which show opportunistic blooms during environmental crisis and dwell at the surface of the water column, survived from the K-Pg mass extinction. This study, for the first time in Turkey, shows blooms of Guembelitria cretacea in the Haymana Basin for the latest Maastrichtian and right after the K-Pg boundary in P0 Zone. Right after the K-Pg boundary, the first samples of the Danian P0 Zone are characterized by Thoracosphaera acme whose diameters are ranging between 10 to 20 microns. In addition to that, another sharp increase was also found in echinoid fecal pellets which peak at 2 cm above the boundary. Previously, the same pellet increment was recognized in the southern part of the basin. These discoveries support the idea of ''Echinoid fecal pellet peak as a K-Pg boundary marker''. In the Haymana Basin, Maastrichtian mudstones are overlain by marls and calcareous mudstone alternations in the Danian indicating a major change in the depositional regime after the K-Pg boundary. A similar stratigraphy has also been observed in the Mudurnu-Göynük Basin in the K-Pg boundary beds. This similarity in an interval of high chronostratigraphic resolution brings the possibility whether these two basins were connected to each other during end Cretaceous and the beginning of Paleocene.


Deep sea benthic foraminiferal diversity and abundance changes across cretaceous-paleogene boundary beds in the Haymana basin (Ankara, Turkey): paleoenvironmental implications
Vardar, Ezgi; Altıner, Sevinç; Department of Geological Engineering (2018)
In order to establish the taxonomy of deep-sea (small) benthic foraminifera and to evaluate their paleoenvironment and paleoecology in terms of relative abundances and diversity, a 14.53 meters-thick section was measured from the Haymana Formation and the Yeşilyurt Formation containing Cretaceous-Paleogene boundary beds in the northern part of the Haymana Basin, Central Turkey. 17 mudstone samples corresponding to 3.15 meters of the upper Maastrichtian and 8 mudstone-marl samples representing 1.21 meters of...
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Sarıaslan, Nisan; Altıner, Sevinç; Department of Geological Engineering (2017)
In order to establish the planktonic foraminiferal biostratigraphy of the Cenomanian- Campanian deposits in the Haymana-Polatlı Basin, a stratigraphic section of 93.5 meters was measured and 75 samples were collected. The stratigraphic section starts with limestones containing late Cenomanian rotaliporid and dicarinellid species and continues with early-middle Turonian aged clayey limestones with sporadic shale beds. These units are overlain by red colored Santonian limestones and shales containing abundant...
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The authors discuss the existence and uniqueness of asymptotically stable unpredictable solutions for some quasilinear differential equations. Two principal novelties are in the basis of this research. The first one is that all coordinates of the solution are unpredictable functions. That is, solutions are strongly unpredictable. Secondly, perturbations are strongly unpredictable functions in the time variable. Examples with numerical simulations are presented to illustrate the theoretical results.
Responses of the planktonic foraminifera to environmental conditions across the cretaceous/paleogene boundary in the Göynük basin, Northwest Anatolia, Turkey
Özder, Rengin; Özkan Altıner, Sevinç.; Department of Geological Engineering (2019)
The aim of this study is to reveal the evolutionary response of the planktonic foraminifera after the Cretaceous/Paleogene (K/Pg) boundary interval in the Göynük Basin, Northwest Anatolia, Turkey. To achieve this purpose, a multidisciplinary study including biostratigraphy and mineralogy was carried out. In the Göynük area, an 8.55 m-thick section was measured, and a total of 47 samples were collected from the Seben Formation and the Hisarözü member of this formation composed of marls and clayey limestones....
Upper paleocene-lowermost eocene planktonic foraminiferal biostratigraphy and record of the paleocene-eocene thermal maximum in the Haymana Basin (Ankara, Turkey)
Tanık, Gamze; Altıner, Sevinç; Department of Geological Engineering (2017)
A rapid global warming event, called the Paleocene-Eocene Thermal Maximum (PETM), took place ca. 56 Ma, marking the Paleocene/Eocene boundary. This event is recorded by a turnover of planktonic foraminifera in deep marine settings, with occurrence of three species so-called planktonic foraminifera excursion taxa (PFET). This work was carried out in order to determine the record of this event in the Haymana Basin, Central Anatolia. The Haymana Basin provides a continuous sedimentary succession starting with ...
Citation Formats
A. U. Karabeyoğlu, “Planktonic foraminiferal diversity and abundance changes across cretaceous-paleogene boundary beds in the Haymana basin and new observations on the extinction horizon,” M.S. - Master of Science, Middle East Technical University, 2017.