Investigation of sedimentological features of lower-middle eocene rocks which outcrop in the east of Lake Van

Sedimentary rocks widely outcrop in the east of Lake Van and in the north of Van city center. The ages of these clastic and carbonate rocks range from Palaeozoic to Quaternary. In this study, the carbonate rocks which were aged as Lower-Middle Eocene in previous studies were studied. The investigation area locates in the Tuşba district of Van Province and take part within 1/25.000 scale Van K50-c3 and c4 topographic sheets. Çobanoğlu and Alabayır villages are the main settlements in the study area which covers approximately 80 km2. During the fieldwork, 3 stratigraphic sections were measured from the locations where the Lower-Middle Eocene rocks were very well observed and the sedimentological features were recorded and a total of 65 samples were taken. Observable sedimentological properties were recorded and a total of 65 samples were taken for analysis. In the course of the laboratory work, 65 thin sections were prepared and examined. The components of the studied rock samples were determined and the carbonate rocks were classified. The rocks are generally biomicrite. According to the characteristics of carbonate rock samples 5 microfacies were determined. These are; 1) Wackestone with Globigerina and Acarinina microfacies, 2) Wackestone-Packstone with Globigerina and Acarinina microfacies, 3) Packstone-Grainstone with Globigerina and Acarinina microfacies. 4) Grainstone with Milioliidae and Red Algae microfacies. 5) Packstone with Nummulites and Red Algae microfacies. These microfacies indicate that Lower-Middle Eocene rocks were formed in depositional environments ranging from shelf lagoon to deep marine. These differences in depositional environments have been interpreted as the result of changes in water level in relation to transgression and regression events.