Foraminiferal and calpionellid biostratigraphy, microfacies analyses and tectonic implications of the upper jurassic – lower cretaceous carbonate platform to slope successions in sivrihisar region (Eskişehir, NW Turkey)

Atasoy, Serdar Görkem
This study focuses on the biostratigraphy, microfacies analyses and the tectonic interpretation of an Upper Jurassic – Lower Cretaceous carbonate succession widely exposed in a tectonic klippe of the Sakarya Zone (Pontides), north of Sivrihisar region (Eskişehir). For this purpose two stratigraphic sections were measured (925 m thick in total) along the carbonate rocks that crop out north of the Dümrek Village. According to the biozonation and the microfacies types, two coeval but dissimiliar depositional domains, separated by an overthrust, have been detected along the measured sections. The one on the southern part shows a slope to basin facies and is characterized by the Kimmeridgian – Berriasian Yosunlukbayırı Formation and the overlying Valanginian Soğukçam Limestone. Within these deposits the following biozones were defined: Globuligerina oxfordiana – Mohlerina basiliensis Zone (Kimmeridgian), Crescentiella morronensis (Saccocoma subzone) Zone (Lower Tithonian), Protopeneroplis ultragranulata Zone (Upper Tithonian), Crassicollaria (massutiniana subzone) Zone (uppermost Tithonian), Calpionella (alpina, Remaniella and elliptica subzones) Zone (Lower Berriasian), Calpionellopsis (simplex and oblonga subzones) Zone (Upper Berriasian) and Calpionellites (darderi subzone) Zone (Lower Valanginian). The Jurassic – Cretaceous boundary is located at the base of the Calpionella Zone. This succession overthrusted from north to south by a thin slice of the Berriasian Yosunlukbayırı Formation and an overlying thicker slice consisting of the Kimmeridgian Günören Limestone which is a part of the Edremit – Bursa - Bilecik Carbonate Platform. Within the Günören Limestone, Labyrinthina mirabilis – Protopeneroplis striata (Kimmeridgian) Zone was recognized. A much thinner section, measured to the north of these successions, consists of the Yosunlukbayırı Formation of Early Berriasian age deposited on the slope and the basinal Soğukçam Limestone. The boundary of these two formations is probably tectonic. If the positions of the studied sections with respect to the Edremit – Bursa – Bilecik Carbonate Platform is considered, the studied basin and slope facies should represent the southern platfrom margin and slope environmnets of this carbonate platform that faced an ocean to the south during the Jurassic – Cretaceous interval. The slope and basinal facies (the Yosunlukbayırı Formation and the Soğukçam Limestone) overthrusted by the shallow marine deposits (the Günören Limestone) in a region studied to the south of the main İzmir – Ankara – Erzincan (İAE) suture suggests an important disruption and shortening of the Edremit – Bursa – Bilecik Carbonate Platform margin and slope deposits probably related to the closure of the İAE ocean.


Foraminiferal paleontology and sequence stratigraphy in the upper visean - serpukhovian deposits (Aladağ unit, Eastern Taurides, Turkey)
Demirel, Seda; Altıner, Demir; Department of Geological Engineering (2012)
The aim of this study is to investigate the Upper Visean substages, delineate the Visean - Serpukhovian boundary with calcareous foraminifera and interpret the foraminiferal evolution and sequence stratigraphical framework by using sedimentary cyclicity across the boundary section. For this purpose a 59,61 m thick stratigraphic section consisting of mainly limestone and partly sandstone and shale is measured in the Aziziye Gediği and Oruçoğlu Formations in the Pınarbaşı Region of Eastern Taurides. A detaile...
Micropaleontological and stratigraphic analyses of the upper jurassic – lower cretaceous Inalti formation (Bürnük, central pontides, Turkey) : remarks on the facies evolution
Kaya, Mustafa Yücel; Altıner, Demir; Department of Geological Engineering (2014)
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 chr...
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...
Geoarchaelogical investigation of central anatolian caravanserais using gis
Ertepınar Kaymakcı, Pnar; Toprak, Vedat; Department of Geological Engineering (2005)
This study comprises analysis of geological, geomorphological constraints that played role in the site selection of caravanserais. In order to do this, 15 caravanserais located along a route from Nevşehir-Aksaray-Konya to Beyşehir were used. The data used in the study include a caravanserai database, lithological maps, and digital elevation model of the area. GIS analyses performed in the study are proximity, visibility, and probability distribution (PDA). The first step is the generation of the ancient tra...
Taxonomy and biostratigraphy of calpionellids and saccocoma across the jurassic-cretaceous boundary beds of the alci block: alacaatli olistostromes, Ankara, Turkey
Akgümüş, Begüm; Altıner, Sevinç; Department of Geological Engineering (2019)
The main aim of this study is to determine the exact position of the Jurassic- Cretaceous (the Tithonian-Berriasian) boundary based on the calpionellid species and their biozones within the pelagic limestone block (Alcı Block). To achieve this aim, the stratigraphic section-BA was measured as 59,30 meters throughout the Alcı Block and totally 72 samples were collected for the preparation of the thin sections. Totally 3 zones and 5 subzones have been designated as Chitinoidella Zone (boneti Subzone), Crassic...
Citation Formats
S. G. Atasoy, “Foraminiferal and calpionellid biostratigraphy, microfacies analyses and tectonic implications of the upper jurassic – lower cretaceous carbonate platform to slope successions in sivrihisar region (Eskişehir, NW Turkey),” M.S. - Master of Science, Middle East Technical University, 2017.