Cold and wet Last Glacial Maximum on Mount Sandıras, SW Turkey, inferred from cosmogenic dating and glacier modeling

In situ cosmogenic 36Cl was measured in boulders from moraines on Mount Sandıras (37.1°N, 28.8°E, 2295 m), the southwestern most previously glaciated mountain in Turkey. Valleys on the north side of the mountain were filled with 1.5 km long glaciers that terminated at an altitude of 1900 m. The glacial activity on Mount Sandıras correlates with the broadly defined Last Glacial Maximum (LGM). The maximum glaciation occurred approximately 20.4±1.3 ka (1σ; 1 ka=1000 calendar years) ago, when glaciers started retreating and the most extensive moraines were deposited. The glaciers readvanced and retreated by 19.6±1.6 ka ago, and then again by 16.2±0.5 ka. Using the glacier modeling and the paleoclimate proxies from the Eastern Mediterranean, we estimated that if temperatures during LGM were 8.5-11.5 °C lower than modern, precipitation was up to 1.9 times more than that of today. Thus, the local LGM climate was cold and wet which is at odds with the conventional view of the LGM as being cold and dry in the region.