Osservazioni su un deposito a blocchi al margine SW della conca di Pescasseroli (Italia centrale)

Abstract

A chaotic deposit (Campo Rotondo deposit) formed of calcareous blocks of various size (up to several ten cubic metres) overlying a calcareous bedrock outcrops on the SW slope of the Pescasseroli valley. The deposit covers an area of about 5 sq.km between the elevations 1,200 and 1,500 m a.s.l. and has a thickness varying between a few metres and 40-50 m. The stability of the slope is governed by two sets of fractures striking N40W and N70W crossing the carbonatic sequence, and by the dip slope attitude of the sequence. On the eastern sector of the studied area the block deposit is dislocated by at least two NW-SE trending faults which brought about well-evident morphological steps. On the basis of field evidence it is assumed that Campo Rotondo deposit was formed by landsliding phenomena of the type debris flow or rock avalanche in Pleistocene times.