This study investigates the depositional history of the Late Eocene sedimentary record in the northwest of the Thrace Basin in a sequence stratigraphic approach and estimates the contribution of regional tectonics, basin physiography and eustasy. Late Eocene sedimentary succession was analyzed in two third-order sequences based on two major data sets / seismic reflection and well data sets. Depositional Sequence-1, represented by progradational stacking patterns, comprises the coarse-grained Hamitabat turbidite system. The base of the Sequence-1 was defined as the base of channel fill deposits in the northern shelf setting and the base of slope fan deposits in the slope setting. This boundary separates Lower-Middle and Upper Eocene sediments. In the slope setting, the Hamitabat turbidite system was analyzed in three major depocenters / Western, Northwestern and Northeastern depocenters respectively. Hamitabat turbidite system was controlled by the interaction of regional tectonics, basin physiography and eustatic fluctuations in the Late Eocene. This study highlighted the role of the regional variables / tectonic influence and basin morphology on the submarine canyon formation. The facies distribution was controlled by the high subsidence rate of sea-floor dominantly instead of eustasy. Depositional Sequence-2, represented by mostly retrogradational stacking patterns, is a clastic-carbonate mixed system. Depositional Sequence-2 was subdivided into three higher-order sequences. The lower sequence boundaries were induced by the rapid relative sea-level rise. The upper boundary of the Depositional Sequence-2 was defined as the termination of clastic-carbonate mixed system and a candidate for the Eocene-Oligocene contact.

Shallowing-upward meter-scale cycles (parasequences) consisting of megalodont-bearing limestones or clay levels at the bottom and fenestral limestones, breccias, stromatolites or vadose pisoids at the top constitute the basic working units of the Upper Triassic successions in the Central and Western Taurides. These cycles are mainly represented by subtidal through supratidal carbonate facies and known as Lofer cycles in the literature. The presence of breccias, mud cracks, dissolution vugs and vadose pisoids indicates subaerially exposed conditions at the top of the cycles. Shallowing-upward meter-scale cycles are interpreted as 4th and 5th order cycles in this study. Megalodont-bearing limestones of the subtidal zone are characterized by wackestones/packstones with abundant involutinids. However, involutinids are poorly represented in the intertidal-supratidal zone. To determine the relationship between cyclicity and foraminifers, the vertical variation of benthic foraminifer abundance has been analysed in the cycles. This analysis leads us to conclude that the foraminiferal abundance decreases from subtidal through supratidal zone. Furthermore, cluster analysis was performed in order to delineate the relation between the biofacies and foraminiferal associations. Micropaleontological analysis of the uppermost Triassic carbonates reveals the presence of restricted platform foraminiferal associations in the studied successions. Foraminiferal associations discovered in the samples belong to the Upper Norian (Sevatian)-Rhaetian Triasina hantkeni assemblage zone. Detailed examination of peritidal carbonates in the Central and Western Taurides against the studies, which claimed that the Dachstein-type platform carbonates are characterized by the transgressive models, should be explained by regressive models.

The aim is to delineate the effective boundary between Lower and Middle Carboniferous (mid-Carboniferous boundary) and to study the meter-scale cyclicity and foraminiferal evolution across a stratigraphic section comprising this boundary. In order to perform such a study, a 25,64 m stratigraphic section, which is mainly composed of carbonates has been measured in the Hadim region of the Central Taurides. In this study, calcareous foraminifers have been studied in the measured section. These foraminiferal assemblages contain 62 species. Based on these foraminifers, four biostratigraphic zones have been defined covering the interval from Upper Serpukhovian to Lower Bashkirian. These zones comprise in ascending order, the Eostaffella ex gr. ikensis &amp / #8211 / E. postmosquensis Zone (Zapaltyubinsky Horizon &amp / #8211 / Upper Serpukhovian), the Plectostaffella jakhensis &amp / #8211 / P. bogdanovkensis Zone and the Millerella marblensis Zone (Bogdanovsky Horizon &amp / #8211 / Lower Bashkirian) and the Semistaffella sp. Zone (Syuransky Horizon &amp / #8211 / Lower Bashkirian). In order to construct the sequence stratigraphic framework, detailed microfacies studies were carried out and eleven different microfacies types were identified. Based on the stacking patterns of these microfacies, six main types of cycles, A-F, and ten subcycles are recognized. Twenty-three shallowing upward meter-scale cycles and three sequence boundaries have been determined in the studied section. The duration of cycles has been calculated as 2 my and cycle periodicities correspond to the Milankovitch eccentricity bant. Results of quantitative analysis of benthic foraminifera have been used to demonstrate the biological response to cyclicity. Eostaffellids, archaediscids, unilocular forms and irregularly coiled bilocular forms are the calcareous foraminiferal groups responding the meter-scale cycles.

An integrated micropaleontological, mineralogical and sequence stratigraphical investigation was carried out across the Cretaceous/Paleogene (K/P) boundary in the Haymana basin, Turkey. A 29.41 m thick boundary section consisting of limestones and marls was measured and 90 samples were analyzed. Biostratigraphic and chronostratigraphic works are based on the planktonic foraminifera. 64 planktonic species were identified and 5 biozones were established. The biozones are, in ascending order, Planoglobulina acervulinoides zone, Racemiguembelina fructicosa zone, Pseudoguembelina hariaensis zone for the Late Maastrichtian / Guembelitria cretacea (P0) zone and Parvulorugoglobigerina eugubina (P1a) zone for the Early Danian. In order to detect the mineralogical changes across the boundary bulk and clay minerals were analyzed using X-ray diffractometry (XRD). Calcite, quartz,feldspar and the clay minerals composed of smectite (montmorillonite) and chlorite are the main components of the rocks. A decrease in calcite and an increase in the detrital minerals (quartz, feldspar) and the clay minerals were detected in the boundary beds. In order to find out the depositional history of the area a detailed microfacies study was performed and 10 microfacies type were determined. The microfacies types defined correspond to slope to basin environment. Based on microfacies analyses, the sequence stratigraphic framework of the boundary beds was constructed. K/P boundary beds were recorded in the transition of transgressive systems tract to highstand systems tract, coinciding with a maximum flooding surface. These beds show a similar pattern with many other K/P boundary beds in different locations of the world indicating eustatic sealevel variations overprint the tectonic control in the basin.

The aim of this study is to investigate the nature of the meter-scale cycles in the &Ccedil / ayraz Formation of the Middle Eocene age and to study the response of foraminifera to the sedimentary cyclicity. In order to perform this study, two stratigraphic sections, which are 44,55 m and 25,95 m in thickness, were measured on a regularly bedded succession mainly composed of carbonates and siliciclastics in the &Ccedil / ayraz Formation of the Haymana Basin. In this study, detailed microfacies analyses were carried out in the studied sections and 10 different microfacies types were identified strictly based on the biofacies in order to define meter scale cyclic sedimentation. Based on the detailed microfacies analysis and the distribution of the vertical facies relationships a composite depositional model is suggested. According to this model, three major facies associations were distinguished, from deepest to shallowest, as: shallow open marine, shoal and lagoon. Studied sections are composed of meter-scale cycles of both upward shoaling or deepening in character and based on the stacking pattern of meterscale cycles two systems tracts were identified along the measured sections. Section 1 is represented by highstand systems tract (HST) and section 2 is represented by lowstand systems tract (TST). In this study, the responses of benthic foraminiferal groups to the sedimentary cyclicity have been documented by quantitative and statistical analysis to understand the shallowing upward cycles, which are fundamental stratigraphic units, in the &Ccedil / ayraz Formation of Middle Eocene age. Among foraminifera, particularly the forms like Nummulites, Assilina and Discocyclina are excellent in order to detect cyclic variations of facies. These studies lead to understand shoaling-upward character of the meter-scale cycles, which are the building blocks of the &Ccedil / ayraz Formation.