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We provide a geomorphological analysis of a glacial valley on Mount Pelister, in Macedonia. Three boulders from a frontal moraine were dated with the cosmogenic nuclide isotope 10Be. The results demonstrate that the boulders have been exposed since 15.24 ± 0.85 ka. This age constrains the formation of the frontal moraine to the Oldest Dryas cold event. This age fits with that of other glacier deposits dated to the Older Dryas in the Alps, Balkans, Carpathians and Turkish mountains. The Pelister palaeoglacier has been reconstructed and its equilibrium line altitude extracted, returning a value of 2250 ma.s.l. This is in good agreement with the equilibrium line altitudes of most other reconstructed glaciers of the same age in the circum- Mediterranean mountains, demonstrating a comparable response to the Oldest Dryas event. Other palaeoenvironmental records near the Pelister mountain indicate that the Older Dryas was here characterized by a cold and remarkably dry event. The temporal relationship between Older Dryas glacier advances in the Balkan region and recorded changes in the Atlantic thermohaline circulation during the Laurentide Ice Sheet massive ice discharge (H1 event) confirms the strong climatic link between the pan-Mediterranean regions and the North Atlantic Ocean. [ABSTRACT FROM AUTHOR]

Ice stream bed topography contains key evidence for the ways ice streams interact with, and are potentially controlled by, their beds. Here we present the first application of two‐dimensional Fourier analysis to 22 marine and terrestrial topographies from 5 regions in Antarctica and Canada, with and without mega‐scale glacial lineations (MSGLs). We find that the topography of MSGL‐rich ice stream sedimentary beds is characterized by multiple, periodic wavelengths between 300 and 1200 m and amplitudes from decimeters to a few meters. This periodic topography is consistent with the idea that instability is a key element to the formation of MSGL bedforms. Dominant wavelengths vary among locations and, on one paleo ice stream bed, increase along the direction of ice flow by 1.7 ± 0.52% km−1. We suggest that these changes are likely to reflect pattern evolution via downstream wavelength coarsening, even under potentially steady ice stream geometry and flow conditions. The amplitude of MSGLs is smaller than that of other fluvial and glacial topographies but within the same order of magnitude. However, MSGLs are a striking component of ice stream beds because the topographic amplitude of features not aligned with ice flow is reduced by an order of magnitude relative to those oriented with the flow direction. This study represents the first attempt to automatically derive the spectral signatures of MSGLs. It highlights the plausibility of identifying these landform assemblages using automated techniques and provides a benchmark for numerical models of ice stream flow and subglacial landscape evolution. MSGL topography consists of superimposed periodic wavelengths as expected in the instability theory of subglacial bedform formationMost of the dominant wavelengths present within one extensive MSGL field increase downstream, suggesting that MSGLs evolve via pattern coarseningFor MSGLs to generate periodic topography, sediment must be able to accumulate or erode (freely move) without fixed anchor points

A complete sequence of glacial deposits and moraines within the same valley system in the Maritime Alps, spanning from the Last Glacial Maximum (LGM) to the Little Ice Age is presented. The sequence is geomorphologically and morphostratigraphically coherent and most stadials have been chronologically constrained by their cosmogenic exposure ages, lichenometry and by correlation with radiocarbon-dated moraines in neighbouring valleys. The shape, extent and thickness of the palaeoglaciers at each stadial have also been reconstructed and their equilibrium line altitude calculated. The LGM moraine of the Gesso Basin bears a similar equilibrium line altitude and age to that of other LGM moraines across the Alps. The recognized Late-glacial stadials show strong similarities with the corresponding stadials of the central–eastern Alpine valleys, such as Gschnitz, Buhl, Daun and Egesen. The recalculation of the exposure ages of moraine boulders with a new production rate better defines the LGM (24.0 ka) and the Egesen Stadial (13.0 ka), while the Buhl Stadial (18.5 ka) is dated for the first time in the Alps. Three early Holocene glacial advances are defined and correlated to the Kartell, Kromer and Goschenen I stadials, widely recognized in other Alpine sectors. Lichenometric dates indicate a three-fold oscillation during the Little Ice Age (thirteenth, seventeenth and nineteenth centuries).