Timing of glaciation in the mediterranean mountains during the last cold stage

Recent research in the mountains of the Mediterranean has attempted to establish the timing of the maximum extent of glaciers during the last cold stage. Several dating methods have been utilised and new dating frameworks have emerged in key areas. In several places, multiple dating techniques (radiocarbon, optically stimulated luminescence, U-series) applied to glacial and associated sediments suggest that local glacier maxima preceded the global Last Glacial Maximum (LGM, ca. 18 14C ka BP/21 cal. ka BP) by at least several thousand years. Studies in Spain, the Pyrenees, the Maritime Alps and Turkey utilising cosmogenic isotope analyses (10Be and 36Cl), have yielded glacial geochronologies with maxima that correlate closely with the marine isotope record of ice volume and the global LGM. In some cases, the use of different geochronological techniques has led to conflicting evidence for the timing of the local last glacier maxima in the same area. From a palaeoclimate perspective, glacier-climate reconstructions for the local last glacier maxima in the mountains of central Italy, northern Greece and western Turkey indicate that climate was wet and cold. In Italy and Greece the local glacier maxima preceded the driest part of the last cold stage - as indicated by palaeoecological records - by several thousand years. For western Turkey, however, recent cosmogenic exposure ages combined with glacier modelling suggest a local last glacier maximum characterised by cold and wet conditions coinciding with the global LGM. The available evidence indicates that a dichotomy is emerging, not only in our understanding of the timing of glaciation across the Mediterranean, but also in the palaeoclimatic interpretations derived from glacial and palaeoecological records. Copyright © 2008 John Wiley & Sons, Ltd.