A new early Miocene fossil forest of the Galatian Volcanic Province (Turkey) and its evaluation in respect of palaeoclimatology

The Galatian Volcanic Province has a rich diversity of fossil wood, and identifying new fossil wood sites, species and forest compositions provides more information about the region's forests and climate in the Early Miocene. Against this backdrop, this study aims to enhance our understanding of the spatial distribution of forest structures, climates and tree compositions in the Early Miocene GVP by identifying fossil trees in the Kıbrıscık-Sarıkaya fossil area. A total of 20 fossil wood samples were collected from the site near the village of Bolu-Kıbrıscık-Sarıkaya. Microscopic analysis revealed the presence of Cedrus anatolica Akkemik, Pinuxylon diversiradiatum (Süss & Velitzelos) Mantzouka & Akkemik, Prunoidoxylon prunoides Akkemik, Salicoxylon galatianum Akkemik, Myricoxylon unalakkemikii H.Çelik, Ulmoxylon kasapligilii Akkemik and Liquidambaroxylon efeae Akkemik. The species composition indicates that the closest living relatives' climatic characteristics suggest an environment where the range of the lowest temperature in the coldest month and the highest temperature in the hottest month varies between − 0.3 and 29.3 °C. In terms of precipitation, the estimated range during the time in which the fossil trees lived was 578–1577 mm. The mean annual precipitation was 1077 mm, higher than the present-day figure of 619 mm (range 493.1–793.8 mm). Consequently, precipitation and temperature in the early Miocene were higher than they are today, and seasonality was more pronounced. The forest structure was characterized by extensive riparian areas and well-drained coniferous and mixed lowland and/or upland forests.