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«After a long period of subtropical climate, during the Quaternary period temperature dropped by about ten degrees. Four glacial periods, interrupted by interglacial ones, characterized the climate of the alpine region and of many areas of the northern hemisphere. The last glaciation, known as «Wurm», shaped the existing pre-glacial relief of the Poschiavo valley and gave it a new morphology. The glaciers flowing down from the southern slopes of the Alps reached the edges of the Po
valley
and formed, amongst others, the Garda, Iseo, Como, Maggiore and Lugano lakes.
Following a change in climatic conditions these glaciers then started to retreat towards the higher regions of the alpine chain. This retreat took place in successive stages, characterized by positive and negative oscillations. The period was studied by C. Burga for the Poschiavo Valley and by L. Huysmans for the Val di Campo.
During the phase denominated Valtellina II, the Poschiavo glacier was about 1’200 meters deep, as documented by a moraine situated at 2’230 meters. For the Val di Campo L. Huysmans found, in the Buril area, eight morainic valleys corresponding to the same number of retreat phases. |
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Palü glacier
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