A new digital Lithological Map of Italy at 1:100.000 scale for geo-mechanical modelling

Abstract

Abstract. Lithological maps contain information about the different lithotypes cropping out in an area. At variance with geological maps, portraying geologic formations, lithological maps may differ as a function of their purpose. Here, we describe the preparation of a lithological map of Italy at a scale of 1:100,000, obtained from classification of a comprehensive digital database and aimed at describing geo-mechanical properties. We first obtained the full database, containing about 300,000 geo-referenced polygons, from the Italian geological survey. We grouped polygons according to a lithological classification by expert analysis of the original 5,456 unique descriptions of polygons, following compositional and geo-mechanical criteria. The procedure resulted in a lithological map with a legend including 19 classes, and it is linked to a database allowing ready interpretation of the classes in geo-mechanical properties, and amenable to further improvement. The map is mainly intended for statistical and physically based modelling of slope stability assessment, geo-morphological and geo-hydrological modelling. Other possible applications include geo-environmental studies, evaluation of river chemical composition, estimation of raw material resources.