Vegetation and climate in the Miocene deposits of southern side of the Büyük Menderes Graben, ?ahinali-2 core, SW Turkey

摘要

Lower-Middle Miocene succession from the ?ahinali coalfield (SW Turkey) was analyzed to reconstruct climate and vegetation. The sediments mainly represent a lacustrine facies and consist of a mudstone-marl dominated succession, including limited coarse-grained clastics. Results of microfloral and published macrofloral records have been considered. The main vegetation types were mixed mesophytic forest dominated by evergreen Quercus and coniferous forest consisting mainly of indeterminate Pinaceae, Pinus and Cupressaceae. In this belt riparian vegetation incorporates high proportions of Alnus , and less amounts of deciduous Salix , Ulmus , Pterocarya , Carya , Platanus , Zelkova and Liquidambar . Herbaceous components in the pollen spectra are in low frequencies, and consist of Poaceae, Brassicaceae, Chenopodiaceae, Ephedra , Asteraceae and Caryophyllaceae. Also three local pollen zones can be recognized based on the changes in relative abundances of palynomorphs. The micro- and published macrofloral records have been subjected to the Coexistence Approach method to obtain the palaeoclimate. Mean annual temperature is estimated to be over 14 °C and mean annual precipitation exceeds 1000 mm. In combination with other climate parameters (temperatures of warmest and coldest months, precipitation of the wettest, driest and warmest months), the data indicate very stable warm-temperate with high annual precipitation. Results of the Coexistence Approach using both sporomorph and leaf datasets are good in agreement, implying internal consistency in the method. Compared with modern meteorological records, surroundings of the Büyük Menderes Graben had similar temperature and higher precipitation during the Early–Middle Miocene. This study contributes to an understanding of the Miocene vegetation and climate evolution in southeastern Mediterranean area.