Quaternary glaciation in the Pindus Mountains, Northwest Greece

Abstract

Geomorphological and geological evidence for former Quaternary glaciation has been mapped in the Pindus Mountains of northwest Greece. The dynamics and chronology of glaciation in this area has been established through sedimentological analysis, soil analysis and Uranium-series dating. Four glacial events are recorded in the sedimentological and geomorphological records. The most extensive recorded glaciation pre-dates 350,000 years BP and was characterised by extensive valley glaciers and ice-fields. A second glaciation occurred prior to the last interglacial, before ca. 127,000 years BP, and was characterised by glaciers that reached mid-valley positions. The height of the last glacial stage in Greece (30-20,000 14C years BP) is recorded by small cirque glacier moraines and relict periglacial rock glaciers. Evidence for a fourth glacial phase is recorded only in the highest cirques of Mount Smolikas (2637 m a.s.l.), the highest peak in the Pindus Mountains. This phase of glaciation is likely to have occurred during the Late-glacial Substage (14-10,000 14C years BP). All of the glaciers during the different glacial stages were reconstructed and used alongside periglacial rock glaciers to determine palaeoclimate. During the glacial maximum of the last glacial stage, mean annual temperatures were ca. 8-9 degrees C lower than at present and mean annual precipitation greater than 2000 mm - similar to modern values. Earlier glacial maxima are likely to have been colder but with mean annual precipitation still greater than 2000 mm. Maximum glacier extent in the Pindus Mountains is likely to have preceded the most severe arid phase of glacial cycles indicated in the pollen record and also global glacial maxima. This was because of the small size of the former Pindus glaciers and their rapid response to climate change, as well as the increased prevalence of aridity around the global glacial maxima. The glacial sequence in the Pindus Mountains represents the best-dated and longest recognised record of glaciation in the Mediterranean region and provides a stratigraphical framework for Quaternary cold-stage climates in Greece.