Palynology and palaeoecology of the miocene coal-beari̇ng Hi̇mmetoğlu basi̇n, Göynük-Bolu-Turkey

Within the scope of this thesis, the palynology and paleoecology of the lignite-bearing sediments of the Miocene Himmetoğlu Basin located in the Sakarya Zone have been studied. The rocks formed during the late Maastrichtian-early Palaoecene constitute basement of the Himmetoğlu lacustrine basin that were deposited in the continenantal area during the Miocene. Miocene lignite bearing deposits are unconformably overlie these basement rocks. The Himmetoglu Formation that crops out at the northwestern side of Himmetoglu Basin consists of mudstone, conglomerates, lignite, organic shale, marl, silicified limestone, claystone and tuffite. In this study, a measured section about 19 m thickness was taken. Samples were compiled from lignite-bearing sediments. Coniferous and broad leaved plants are dominant in the palynological asssociations. Pityoposorites labdacus, Pityosporites microalatus, Momipites punctatus, Tricolporopollonites megaexactus ssp. brühlensis, Tricolpopollonites microhenrici, Ulmipollonites undulosus and Alnipollonites verus are abundant along the sequence. Green algae Botryococcus braunii and Sigmapollis pseudosetarius indicating the freshwater environment were also reported. According to changing of polen percentages, five different local polen zones were determined. Sedimentation occurred during the Early-?Middle Miocene due to less variety and percentages of spores and low rate of Momipites quietus, Subtriporopollonites anulatus ssp. nanus and Platycaryapollonites miocaenicus. The palaeoclimate data obtained are between 17.2 and 21.1 °C for the average annual temperature and winter and summer temperatures changes between 5.5 and 13.3, 27.3 and 27.9, respectively. Annual precipitation is between 1217 and 1355mm. Plant cover does not show a significant change but there are some small fluctuations in temperature and precipitation along the sequence. As a result during the sedimentation the climate smay have been hot, rainy and humid. Keywords: Early-Middle Miocene, Göynük, Himmetoğlu Formation, Palaeoecology, Palynology.