Palaeoclimatic evolution of the Eocene marine sediments in Yozgat

In this study, 16 samples recovered from the coal seam in Arabın district within the Çankırı-Çorum basin are examined by means of palynology. The area is of two different stratigraphic units consisting of Çiçekdağı unit as the basement and sedimentary sequence of Çankırı-Çorum basin unconformably overlying the basement unit. The sampled coal seam is located within the Yoncalı formation of the sedimentary unit. The pollen forms observed in the samples indicate that these samples were precipitated during Middle-Late Eocene times. In addition, observed pollens belonging to the mangrove and back mangrove plants show that tropical climate prevails during those times and the precipitation area was close to the marine environment. Temperature values were obtained for the first time for Arabın district by using coexistence approach method, and the results support the existence of tropical climate conditions in the area. Northern part of the Çankırı-Çorum basin is represented by the fresh water flora developed in the plain, swamp and riverside environments. In the southern part, marine environment conditions are predominant, and these type of flora is less common. Thermophile plants representing the tropical climate conditions in both north and south of the basin are widespread. In addition, Pinus living in moderatetopography areas and Pinaceae are observed only in samples from southern part. This is interpreted that southern part of the basin was topographically higher during MiddleLate Eocene times. In conclusion, palynological data indicates that humid tropical climate conditions prevailed in Anatolia during Middle-Late Eocene, and temperature and humidity were much higher along the coastline while cooler climate conditions co-existed landwards. Accordingly, paleo-topography in land areas of the Anatolia should have had low or moderate elevations covered by a mixed forest community.