High-resolution palynological analysis in late early-middle Miocene core from the Pannonian Basin, Hungary: climatic changes, astronomical forcing and eustatic fluctuations in the Central Paratethys

High-resolution palynological analysis in the Karpatian-Sarmatian (late early-middle Miocene) interval of the borehole Tengelic 2 (Hungary) reveals the existence of a forest organized in altitudinal belts developed in a subtropical-warm temperate humid climate, reflecting the so-called Miocene climatic optimum. Pollen changes from the late early Miocene to the middle Miocene are related to climatic variations. Values of mean annual temperature (Ta) between 18 and 20 °C and mean annual precipitation (Pa) between 1200 and 1400 mm have been estimated (“climatic amplitude method”) for the Badenian. Decreasing during Late Badenian and Sarmatian, Ta and Pa about 16 °C and 1100 mm, have been interpreted as a climatic cooling correlated with the “Monterey cooling event” and related to the development of the East Antarctic Ice Sheet (EAIS). Alternation in pollen taxa (thermophilous vs. altitudinal elements) reflects the astronomical forcing on temperature and precipitation and then on vegetation, where obliquity and eccentricity cycles dominated. Eustatic changes determine Pinus and Pinaceae and dinocyst variations.