Last Glacial Maximum and Younger Dryas piedmont glaciations in Blidinje, the Dinaric Mountains (Bosnia and Herzegovina): insights from 36Cl cosmogenic dating

Abstract

The highest parts of the Dinaric Mountains along the eastern Adriatic coast of the southern Europe, known for their typical Mediterranean karst-dominated landscape and very humid climate, were glaciated during the Late Pleistocene. Palaeo-piedmont type glaciers that originated from Čvrsnica Mountain (2226 m a.s.l.; above sea level) in Bosnia and Herzegovina deposited hummocky, lateral and terminal moraines into the Blidinje Polje. We constrained the timing of the largest recognized glacier extent on Svinjača and Glavice piedmont glaciers by applying the cosmogenic 36Cl surface exposure dating method on twelve boulder samples collected from lateral, terminal and hummocky moraines. Using 40 mm ka–1 bedrock erosion rate due to high precipitation rates, we obtained 36Cl ages of Last Glacial Maximum (LGM; 22.7 ± 3.8 ka) from the hummocky moraines, and Younger Dryas (13.2 ± 1.8 ka) from the lateral moraine in Svinjača area. The amphitheater shaped terminal moraine in Glavice area also yielded a Younger Dryas (13.5 ± 1.8 ka) age within the error margins. Our results provide a new dataset, and present a relevant contribution towards a better understanding of the glacial chronologies of the Dinaric Mountains. Because our boulder ages reflect complex exhumation and denudation histories, future work is needed to better understand these processes and their influence on the cosmogenic exposure dating approach in a karstic landscape.