Glacial history - Mediterranean Mountain Environments - page 37

chronostratigraphical framework. In Bruno Messerli's classic review of glaciation
(Messerli, 1967) many areas still remained in the pioneer phase although the vol-
ume of research on the glacial history of the Mediterranean was very large, with 364
publications cited in Messerli's review. However, whilst Messerli's paper could be
regarded as representing the 'watershed in pioneer phase research' in the Mediter-
ranean mountains (Hughes et al. , 2006a, p. 335), the last three decades of the twen-
tieth century was a period of stagnation in the development of ideas with few papers
advancing knowledge beyond the mapping phase.
The final phase in the evolution of glacial research in the Mediterranean moun-
tains was termed the 'advanced phase' by Hughes et al. (2006a) and is charac-
terized by the application of radiometric dating, and the development of detailed
geochronologies combined with modern sedimentological and stratigraphical anal-
yses. The earliest contributions to this phase applied radiocarbon dating to glacial
lake sediments. Often this research was undertaken not by glacial geomorpholo-
gists but by palaeoecologists, such as Janssen and Woldringh (1981) in the Serra
da Estrela, Portugal, Mardones and Jalut (1983) and Andrieu et al. (1988) in the
Pyrenees, and Allen et al. (1996) in the Sanabria National Park, Spain. However, in
the 1990s radiocarbon dating was utilized directly by scholars such as Giraudi and
Frezzotti (1997) for understanding the timing of glaciations. The number of studies
examining the geochronology of glaciations in the Mediterranean mountains has ac-
celerated dramatically in the first decade of the twenty-first century, especially with
the development of cosmogenic nuclide exposure dating. Many new papers are now
appearing every year, whereas just a decade ago glacial research in the region was
largely dormant. Thus, it would seem that our knowledge of glacial history of the
Mediterranean region is rapidly reaching an advanced phase. However, that is not to
say that our knowledge is complete. New evidence on the timing of glacial advances
in different parts of the Mediterranean is presenting new problems and questions,
and this is likely to spur a new era of prolific research in this field.
3.2 Pleistocene glaciations in the
Mediterranean mountains
The mountains surrounding the Mediterranean basin have been glaciated on sev-
eral occasions through the Quaternary (Hughes et al. , 2006a). The geological and
geomorphological record of glaciation in these mountains provides valuable infor-
mation on past climates, since glaciers are closely related to atmospheric air tem-
peratures and moisture supply. Ice has sculpted and shaped pyramidal peaks, aretes,
cirques and glacial troughs and produced moraines and glacial lakes in areas as
diverse as Morocco and Montenegro. Glaciers have also affected other processes
and had a profound impact on fluvial systems down-valley (Woodward et al. , 2008)
and, in limestone massifs, left a major imprint on karst geomorphology (Hughes
et al. , 2007a).