Geochronology and ice-flow modelling of the Late Quaternary glaciers on Mt. Soğanlı, Türkiye

Abstract

Understanding Earth's climate history through the chronology and reconstruction of palaeoglaciers is a central topic of palaeoclimatology. Examining the remnants of past glaciations preserved in isolated alpine environments provides insight into critical palaeoclimatic conditions. Accurate dating techniques, such as terrestrial cosmogenic nuclides, are crucial for understanding the timing of these changes. The Anatolian Peninsula, characterized by diverse topographical and climatic factors, witnessed the presence of glaciers during the Late Pleistocene, shaping its alpine landscape significantly. While mountain ranges such as the Taurus and Pontic favoured glacier development due to their elevation and lower temperatures, isolated mountains such as Mount Soğanlı in the interior hinterland also supported significant palaeoglaciers. Despite previous studies on Anatolia's glaciers, numerical dating of glacial deposits on Mount Soğanlı has remained elusive until now, hindering precise palaeoclimatic interpretations. This study employs cosmogenic ³⁶Cl surface exposure dating and physical-based ice-flow modelling using an open-source framework, Parallel Ice Sheet Model (PISM), to determine the timing of glaciations and to reconstruct past glacier extents on Mount Soğanlı. The results reveal glacier retreat ages of 48.3 ± 13.4 and 18.3 ± 4.4 ka based on two well-preserved moraines. Additionally, palaeoclimate simulations matched with the field observations indicate considerably colder conditions (6.65–8.15°C colder than today) necessary to sustain glaciers on Mount Soğanlı, when precipitation amounts were the same as today. These findings contribute to a better understanding of Anatolia's palaeoclimatic fluctuations and align with similar studies in neighbouring regions, enhancing our knowledge of past climate dynamics of the Eastern Mediterranean and the Middle East.