CLIMATE RECONSTRUCTION OF SOUTHERN UKRAINE IN THE OLIGOCENE ON THE BASIS OF SPORE-POLLEN STUDY DATA BY THE COEXISTENCE APPROACH METHOD

Abstract

Based on the data of spore-pollen studies of the Oligocene sediments of Southern Ukraine, a reconstruction of the Oligocene climate of this region was carried out using the latest method of coexistence approach. For each of the intervals of Oligocene time (early Borysphenian, late Borysphenian, Molochanian, Sirogozian, Askanian, and Hornostaivian) the values of the following climatic parameters were calculated: mean annual temperature, coldest month temperature (January), warmest month temperature (July), mean annual precipitation, highest month precipitation, lowest month precipitation, warmest month precipitation. It was established that the paleoclimate was warm, close to subtropical, with dry hot summers. It is classified as Csa type according to Köppen. A trend of gradual cooling and aridization of the climate within Southern Ukraine during the Oligocene was revealed. In the middle of the Oligocene (Molochanian — Sirogozian) an episode of noticeable warming and drying: an increase of continentality of the climate was recorded (an increase of mean annual temperature and a decrease of precipitation in the wettest month, a decrease of precipitation in the driest month and a decrease of precipitation in the warmest month), which corresponds to the period of the least development of the sea basin within the Southern Ukraine in the Oligocene.