Criteri per evidenziare l'evoluzione recente di faglie

Abstract

The first part of the paper critically examines the relationships between a fault and the topographic surface, intended as the morphological expression of cover formations, the sedimentary body of these formations, their bedrock surface. It is concluded that: a) the morphological expression of a fault cannot be univocally interpreted; b) only in specific cases the relationships between faults and sedimentary body give significant information; and c) more reliable information can instead be deduced from the relationships between faults and bedrock surface on which cover formations lie. With the aid of two particularly significant examples the second part of the paper examines the possible reciprocal interactions between fault and water course evolution, the latter affected by the fault itself. The importance of distinguishing between "rejuvenated" and new faults in the analysis of fault geometry in relation to cover formations is emphasised. The various links between fault surface and either bedrock or cover formations in the area of a rejuvenated type fault are also considered. In conclusion it appears to be objectively impossible to identify all the faults of recent evolution that are present in a given area either because of a lack of evidence or because this cannot be highlighted. It is hoped that the new cartographic project in the scale 1:50,000 of Italy will adopt a symbolism which will aid distinction between "rejuvenated" and new faults.