Late Quaternary glaciations and cosmogenic ³⁶Cl geochronology of Mount Dedegöl, south‐west Turkey

Abstract

We present details on the timing of glaciations during the late Quaternary in the western Taurus Mountain Range of Turkey. Twenty‐five boulders from prominent moraines in three northern glacial valleys of Mount Dedegöl (37.40°N, 31.17°E, 2992 m above sea level, ∼15 km west of Lake Beyşehir) were dated based on cosmogenic 36Cl surface exposure. The geomorphological mapping of the N‐NE‐trending Sayacak, Kisbe and Karagöl valleys and their in situ produced 36Cl glacial chronology revealed several glacial episodes during the late Quaternary from (pre‐Last Glacial Maximum (pre‐LGM) to early Holocene. Pre‐LGM glaciations are represented by a push‐hummocky moraine complex in the northern Sayacak Valley and dated to 29.7 ± 2.9 ka. The ages obtained from these hummocky moraines give substantial evidence regarding ice accumulation before the global LGM. In the same valley, glaciers reached their maximum positions at the LGM and deposited lateral moraines at 19.7 ± 1.6 ka. Lateglacial moraines were dated to between 16.4 ± 0.7 and 12.0 ± 1.0 ka in the nearby east‐facing Karagöl valley. The youngest glacial stages occurred during the Younger Dryas stadial (11.5 ± 0.8 ka) and early Holocene (9.8 ± 1.4 ka) in Mount Dedegöl.

The glacial history of Greece: a comprehensive review

“…The shift of this local glacier maximum on Mt Chelmos prior to the global LGM, is in accordance with evidence from the other mountains across the Mediterranean like northern Spain (Serrano et al 2012a, b;Oliva et al 2019), the Italian Apennines (Giraudi and Frezzotti 1997), and Turkey (Sarıkaya et al 2014). Interestingly, cosmogenic dates from the western and central Taurus Range in Turkey suggest similar pre-LGM glacier advance phases: at 35 ± 2.5-28.1 ± 2.6 ka ( 36 Cl) on Mt Akdağ (Sarıkaya et al 2014) at 46.0 ± 7-29.8 ± 2.3 ka ( 36 Cl) on Mount Bolkar (Çiner and Sarıkaya 2017) and at 29.7 ± 2.9 ka ( 10 Be, 26 Al)) on the nearby Dedegöl Mountains (Köse et al 2019).…”

Modelling Last Glacial Maximum ice cap with the Parallel Ice Sheet Model to infer palaeoclimate in south‐west Turkey

“…A later advance in the Muslu Valley occurred 15.2 ± 1.1 ka during the Late Glacial (Zahno et al, 2009;after Reber et al, 2014). Recently, Köse et al (2019) dated 25 limestone boulders from moraines in the Sayacak, Kisbe and Karagöl valleys by using cosmogenic 36 Cl, and found substantial ice accumulation in the northern Sayacak Valley before the global LGM (29.7 ± 2.9 ka). Glaciers reached their maximum positions during the LGM (19.7 ± 1.6 ka) and retreated to less extensive positions between 16.4 ± 0.7 and 12.0 ± 1.0 ka.…”

“…Glaciers reached their maximum positions during the LGM (19.7 ± 1.6 ka) and retreated to less extensive positions between 16.4 ± 0.7 and 12.0 ± 1.0 ka. According to Köse et al (2019), the latest glacial advances occurred from the Younger Dryas stadial to Early Holocene (11.5 ± 0.8 to 9.8 ± 1.4 ka).…”

“…We chose to study Mount Dedegöl, because (i) there is a complete LGM glacial chronology established on the mountain. Previous studies used cosmogenic isotopes [ 10 Be, 26 Al: Zahno et al (2009;36 Cl: Köse et al (2019)] and indicated that the glaciers were at their largest extent during the LGM. The ages indicated that the glaciers started to retreat by 21.5 ± 1.5 ka at Muslu Valley (Zahno et al, 2009) and by 19.7 ± 1.6 ka at Sayacak Valley (Köse et al, 2019).…”

“…Previous studies used cosmogenic isotopes [ 10 Be, 26 Al: Zahno et al (2009;36 Cl: Köse et al (2019)] and indicated that the glaciers were at their largest extent during the LGM. The ages indicated that the glaciers started to retreat by 21.5 ± 1.5 ka at Muslu Valley (Zahno et al, 2009) and by 19.7 ± 1.6 ka at Sayacak Valley (Köse et al, 2019). There is no other mountain in the eastern Mediterranean dated by different isotopes ( 10 Be, 26 Al and 36 Cl) and provided similar results.…”