Una ipotesi di cronologia glaciale würmiana, tardo e post-würmiana nell’Appennino Centrale

An hypothesis of Würmian, Late and Post Würmian glacial chronology in the Central Apennines

Abstract

Even though the Pleistocene Glaciation has left some traces in the Central Apennines since Riss age, the greatest glacial witness are to be referred to the glaciation called Würm in the Alps. On the basis of actual knowledgements we may easily think that the largest advance of the Apennines glaciers has to be attributed to the stage called Würm III. Witness of the existence of a diffused glacialism in the Late Würmian age exists also in the Central Apennines. In all reliefs numerous morainic apparata, having the characteristics of stadial deposits, exist in fact inside as for the Würmian III terminal moraines. We can therefore assert that also in the Apennines the withdrawal of the glaciers after the phase of the greatest Würmian sloping did not occur in a continuous way, but with some phase of rest or partial re-advance. Three fundamental Apennines stages are distinguished. The entity of the subsequent withdrawals caused the limit of perpetual snow to rise of relatively constant values during the single stage in the several montaneous groups and significantly comparable with the limits noticed in the late Würmian stages of the Alps (Altstadien, Buhl-Schlern e Gschnitz). The most complete succession is the one of Gran Sasso, where, perhaps a IV stage may be found and where, as for the actual existence of the Calderone Glacier, also the effect of the latest stadial oscillations must have been felt. A summary examination shows that stadial phases or stages existed also in the Northern and Southern Apennines during the withdrawal of the Würmian glaciers; therefore they end by assuming a general significance.