Stratigraphical, sedimentological, geochemical and cyclostratigraphical analyses of upper cretaceous (Upper santonian- campanian) pelagic successions of haymana and Mudurnu-Göynük basins of the Sakarya continent, Turkey


Thesis Type: Postgraduate

Institution Of The Thesis: Orta Doğu Teknik Üniversitesi, Faculty of Engineering, Department of Geological Engineering, Turkey

Approval Date: 2014

Student: BAKHT ZAMIR AFRIDI

Consultant: İSMAİL ÖMER YILMAZ

Abstract:

The Upper Cretaceous (Upper Santonian-Campanian) successions were measured from two different basins of Turkey, Haymana basin and Mudurnu-Göynük basin. The measured Alagöz and Göynük sections are dominantly composed of red marly beds and fine grained siliciclastic green-gray beds with occasional interruption of fine grained turbiditic bedding. A variety of lithofacies are identified in the studied sections, including radiolarian packstone, silty marls, marls, mudstone, claystone, siltstone and fine grained quartzwacke sandstone. Abundant planktonic foraminifers and low presences of other microfossils are observed within the thin sections. The grains are mostly quartz with less percent of accessory minerals. The depositional environments are interpreted as oxic to suboxic deep marine environment with occasional interruption of turbiditic current and low contribution of organic matter. The low concentrations of P/Al and certain trace element ratio, suggests low nutrient supply and low primary productivity. The Alagöz Section is characterized by Fe-rich and Fe-poor lithologies, while Göynük lithologies possess Fe-poor character. The correlation coefficient of oxides and trace elements indicate terrigenous influx. The D* values and low Ti/A/ ratio suggest fluvial influence and also reflect transgressive condition. The ratios of oxides,trace elements and Eu-anomalies represent mafic to felsic source rock for Alagöz Section and felsic source rock for Göynük Section. The ratio of trace elements and Ce anomalies in the studied sections indicate oxic to dysoxic marine environmental conditions during the deposition. The high resolution cyclostratigraphy of the measured sections indicate centimeter to meter-scale cyclic bedding with few episodic cycles at different levels. The cyclic bedding may imply the collaboration of small-scale sealevel fluctuations and/or tectonic effect and changes in productivity.