CASTIGLIONI G. B.
Forme di accumulo glaciale – Glacial accumulation landforms
Pages 69-72
Abstract
The Pleistocene morainic deposits distributed along the Alpine margin form very typical groups ofhills which penetrate the plain to a distance of 15-20 km (morainic amphitheatres ofIvrea) ofTicino river} ofBrianza, ofTagIiamento river) or even 30 km (Garda amphitheatre). Minor groups of hills are not listed here. Among the larger hills is the «Serra di Ivrea» (East of the town of the same name), which reaches an altitude of about 400 m on its inner side. It is more than 15 km long, rectilinear in shape} and has multiple} close-set ridges (fig. 8.1). The youthful shape of these reliefs} and the contrast between their ridges and depressions} is not the same everywhere} since the various arcs ofhills ofancient glaciations are smoothed and softer in shape} due to the greater weathering phenomena they underwent. These morphological differences are not so marked in the foothill belt of the Italian Alps as they are in the morainic complexes of the northern flank} where solifluction phenomena have remodelled the landscape to a greater extent and where sedimented loess covers reach greater thicknesses. As regards the remodelling of these hills} emphasis should be laid on extensive and evident anthropic impact} sometimes recent) and in particular terracing and flattening carried out for agricultural purposes. Among the hills} there are several reliefs composed of pre-Quaternary bedrock and others simply covered with glacial deposits. In any case} the morphology of the buried bedrock underlying the glacial deposits is believed to be very irregular} remodelled by glacial processes to some extent} and varying from place to place. Fluvial erosion was certainly important during the older modelling phases of this substrate: valleys} now buried, had already formed in the Messinian} particularly in the area near Como and Varese (Felber & Bini, 1997) (see Chapter 6) section 6.2; and Chapter 15} section 15.3). As regards the Geomorphological Map, no specific survey of the hill groups of glacial origin has been made. In…
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