Micropaleontological and stratigraphic analyses of the upper jurassic – lower cretaceous Inalti formation (Bürnük, central pontides, Turkey) : remarks on the facies evolution

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2014
Kaya, Mustafa Yücel
This thesis aims to conduct a thorough investigation on the Upper Jurassic – Lower Cretaceous İnaltı Formation which is a significant unit for the regional geology of Turkey. Conducted investigation involves micropaleontological and microfacies analyses integrated with stratigraphic interpretations. In the vicinity of Bürnük Village, a 395 m thick stratigraphic section, overlying the Bürnük Formation and underlying the Çağlayan Formation, was measured and 101 samples were collected. Biostratigraphic and chronostratigraphic works are based on the benthic foraminifera and encrusting sponge Calcistella jachenhausenensis. 44 species of foraminifera belonging to 35 genera, and 13 species of microencrusters were identified and 3 biozones were established. The biozones are Mesoendothyra izjumiana zone, Calcistella jachenhausenensis zone and Protopeneroplis ultragranulata zone in ascending order. Detailed microfacies analysis revealed the depositional history and carbonate platform evolution in the area. 15 microfacies types were determined in 5 different environments corresponding to slope, fore-reef, reef, back-reef and lagoonal environments on the carbonate platform. A vertical facies shift from platform margin (reef, fore-reef) - slope facies to inner platform (back reef-lagoonal) facies was observed in the Berriasian. Before cutting by Çağlayan clastics, again a facies shift towards the platform margin-slope facies took place in the studied part of the İnaltı carbonate platform. The studied section was correlated with some J-K boundary sections from different parts of the world. It is concluded that mentioning a general shallowing trend at/around the J-K boundary for all the correlated sections is not possible due to the preponderant local tectonics.
Citation Formats
M. Y. Kaya, “Micropaleontological and stratigraphic analyses of the upper jurassic – lower cretaceous Inalti formation (Bürnük, central pontides, Turkey) : remarks on the facies evolution,” M.S. - Master of Science, Middle East Technical University, 2014.