Last deglaciation in the central Balkan Peninsula: geochronological evidence from the Jablanica and Jakupica Mts (North Macedonia)
Authors: Ruszkiczay-Rüdiger Zsófia , Kern Zoltán , Temovski Marjan , Madarász Balázs , Milevski Ivica , Braucher Régis , Lachner Johannes , Steier Peter , Team Aster 
Published: March 2020

&lt;p&gt;Several studies applied numerical age determination methods to examine glacial phases of the central Balkan Peninsula. However, the resulting conflicting datasets require further discussion. This study provides &lt;sup&gt;10&lt;/sup&gt;Be Cosmic Ray Exposure (CRE) ages of a succession of glacial landforms in the Jablanica and Jakupica Mts (North Macedonia), aiming at a better understanding of Late Pleistocene glacier development in the area.&lt;/p&gt;&lt;p&gt;In the Jablanica Mt. (~41.25&amp;#176; N; Crn Kamen, 2257 m a.s.l.) six glacial stages were identified (Temovski et al., 2018). The CRE ages of five glacial stages (from the second oldest to the youngest) range from 16.8&lt;sup&gt;+0.8&lt;/sup&gt;/&lt;sub&gt;-0.5&lt;/sub&gt; ka to 13.0&lt;sup&gt;+0.4&lt;/sup&gt;/&lt;sub&gt;-0.9&lt;/sub&gt; ka. Accordingly, the most extensive glaciation in the Jablanica Mt. occurred before ~17 ka (Ruszkiczay et al., 2020).&lt;/p&gt;&lt;p&gt;Based on the accumulation area balance ratios (AABR) of the reconstructed glaciers, their mean equilibrium line altitudes (ELAs) were estimated. The average ELA of the glaciers was 1792&amp;#177;18 m a.s.l. during the largest ice extent, and 2096&amp;#177;18 m a.s.l. during the last phase of the deglaciation.&lt;/p&gt;&lt;p&gt;Independent reconstructions of key climatic drivers of glaciological mass balance suggest that glacial re-advances during the deglaciation in the Jablanica Mt. were associated to cool summer temperatures before ~15 ka. The last glacial stillstand may result from a modest drop in summer temperature coupled with increased winter snow accumulation. In the study area no geomorphological evidence for glacier advance after ~13.0&lt;sup&gt;+0.4&lt;/sup&gt;/&lt;sub&gt;-0.9&lt;/sub&gt; ka could be found. Relying on independent climate proxies we propose that (i) the last glacier advance occurred no later than ~13 ka, and (ii) the glaciers were withdrawing during the Younger Dryas when low temperatures were combined with dry winters.&lt;/p&gt;&lt;p&gt;In the Jakupica Mt. (~41.7&amp;#176; N, Solunska Glava, 2540 m a.s.l.) a large plateau glacier was reconstructed. The study area comprised six eastward facing, formerly glaciated valleys. Cirque floor elevations range from ~2180 m a.s.l. at Salakova Valley, to between ~2115 and ~2210 m a.s.l. on the carbonate plateau. The lowest mapped moraines are descending down to 1550-1700 m a.s.l. Due to the large plateau ice and the complicated system of confluences, glacier reconstructions using semi-automated GIS tools are problematic. Four to six deglaciation phases were reconstructed, and a preliminary estimation of the ELAs based on the maximum elevation of the lowermost lateral moraines leads to ELA values of 1800&amp;#177;50 m a.s.l. for the most extended phase. Multiple CRE ages for the subsequent glacial stages are also being acquired for Jakupica Mts.&lt;/p&gt;&lt;p&gt;This research was supported by the NKFIH FK124807 and GINOP-2.3.2-15-2016-00009 projects, by the INSU/CNRS and the ANR through the program &amp;#8220;EQUIPEX Investissement d&amp;#8217;Avenir&amp;#8221; and IRD and by the Radiate Transnational Access 19001688-ST.&lt;/p&gt;&lt;p&gt;Ruszkiczay-R&amp;#252;diger Zs., Kern Z, Temovski M, Madar&amp;#225;sz B, Milevski I, Braucher R, ASTER Team (2020) Last deglaciation in the central Balkan Peninsula: Geochronological evidence from Jablanica Mt (North Macedonia). Geomorphology 351: 106985&lt;/p&gt;&lt;p&gt;Temovski M, Madar&amp;#225;sz B, Kern Z, Milevski I, Ruszkiczay-R&amp;#252;diger Zs. (2018) Glacial geomorphology and preliminary glacier reconstruction in the Jablanica Mountain, Macedonia, Central Balkan Peninsula. Geosciences 8(7): 270&lt;/p&gt;