in order to learn about the effect of climatic variations on alpine environments, it is not necessary to look at the passage of mountain EMES systems. Since the last maximum glacial (LGM), about 20 000 years ago, the alpine glaciers have withdrawn from the lowlands and their build-up areas at altitude. This transition took into account the alpine eography by allimating large freshwater lakes, releasing a sense of quality from editions and exposing large” and rocky surfaces. However, the rebuilding of environmental conditions since the GML remains undocumented. One of the main limitations is the lack of time constraints in the reconstruction of the glacial extensions passed. I am delighted by ethos that have ‘and’ have been prepared and applied to date the gomorphological or specific eomorphologic markers of glacier dynamics. ‘Ecently, the timing of surface exposure by luminescence stimulates optically (OSL) to ‘and’e d’eel’, providing an opportunity to elicit the reconstructions of the glacial extensions passed. This ethode is based on the awareness ‘e’ of the OSL signal of the miners ‘to the light’. During an exhibition, the OSL signal is given ‘a z’ero in the first miles of the exposed rock surface. In this t-’ese, I ‘investigate the potential of the OSL surface exposure date from glacial polishes on the sidewalls of the Glace Sea, embossing the Ematic of the Mont-Blanc massif. First of all, I can show that this ethode allows me to rebuild the ‘walkers’ of the glacier from the Petit Amaige glacial, that is to say, from the moth deuxime of the 19th of its own. I then show that over longer periods of eriodes, my ethode is sensitive to ‘surface erosion’. By combining it with another ethode of timing: the timing by cosmog’ eny nucl Eide shows that it is possible to compel the ‘evolution of the surface erosion and variations in the thickness of the ice-cream tree over the last 20 000 years’. Applying this new approach to vertical profiles of fly rock surfaces on the edges of the Glace Sea, I believe that the intensity of ‘erosion’ varies with the altitude. The higher the surfaces, the smaller the erosion. In addition, the results of these mountainous environments tend to be strong in comparison with what is accepted in these mountainous environments. Vertical distribution and intensity of ‘erosion rates’ would be the equence of morpho’ etric and climatic factors specific to the high-mountainous environment, such as the slope of rocky surfaces or the distribution of the snow coat. Finally, the glacial reconstitutions suggest secnarios of potentially rapid glacial slimming at the end of the last maximum glacial.