Abstract: This study explains the palaeoecological aspects of the lignite-bearing sediments from the Late OligoceneEarly Miocene Kalkım-Gönen Basin. Studies were carried out in two different areas, Ünsa and Metehan.A core drilling was performed by a private company, Ünsa mining, about 187 m long. Fine grainedlignite bearing deposits alternated with volcanics are dominant along the core. In the Metahan area,lignites with clastic deposits alternation are available as well. Sequence includes primary and secondarygypsum formations in some places. Sediments in the region is densely faulted and folded and orientationsof fold axis is mainly northeast-southwest directed. A section was measured from the open pit minereaching to approximately 30 m thick coniferous plants undifferentiated Pinaceae and Cupressaceae,riparian plant Alnus are in high percentages in the samples from the Ünsa drilling. The main elementsof the mixed mesophytic forest are Engelhardia, Castanea-Castanopsis, Quercus spp., and evergreenQuercus that were recorded in minor quantities. Spores, herbaceous and swamp plants are represented bylowest quantities. Three local pollen zones (Ü/1-3) may be distinguished according to changes on pollenconcentration. Metehan sporomorph associations are rich with respect to elements of coniferous forest(undifferentiated Pinaceae), mixed mesophytic forest (Engelhardia, evergreen Quercus, Quercus spp.,Fagus, Carpinus) and riparian plants (Alnus). Spores are relatively in low amounts. Swamp forest andherbs constitute the lowest percentages. Counting results indicate the existence of two different local pollensub-zones (M/1-2) corresponding to Ü-2 zone of the Ünsa sporormorph associations. Pollen assemblagesidentified in both areas indicate the presence of a dense forest cover during the deposition. Within thisforest, mixed forest plants (evergreen Quercus, Quercus spp., Engelhardia, Castanea-Castanopsis) andconifers (undifferentiated Pinaceae, Cupressaceae, Keteeleria, Cedrus, Cathaya, Picea). Alnus is the mostabundant plant on the edges of the river. In this environment, plants such as Ulmus, Zelkova, Carya,Pterocarya and Liquidambar occur in lesser amounts. Quantitative palaeoclimate results and pollenassemblages in both areas (Kalkım-Gönen Basin) indicate that lignite-bearing sediments were depositedunder humid, hot and rainy conditions.