Comparison between remote sensed lineaments and geological structures in intensively cultivated hills (Monferrato and Langhe domains, NW Italy)

Abstract

Stereo and panchromatic Spot HRV and GTC ERS‐2 SAR images were used to study the correspondence between the lineament systems and geological structures of hills composed of marly‐arenaceous sediments with rich vegetation and extensive human activities, namely the Monferrato and Langhe domains (north‐west Italy). In this context, a large number of lineaments are usually found and their correspondence with geological structures is mainly non‐direct. Since the lineaments belonged to homogeneous, well‐represented geometrical families, ‘geometrical filters’ were used to reduce the complexity of the lineament patterns. The lineaments were statistically analysed and four systems were individuated for each domain. Comparison between the lineaments and the geological structures revealed distinct geometrical and distribution similarities. The geological meaning of the lineaments has been thus investigated. In the highly deformed Monferrato domain it was determined by comparison with the detailed geological model, whereas in the poorly and uniformly deformed Langhe comparison was made with mesostructural analysis and the geometry of its drainage network. The good correspondences in both domains are probably due to a structural control during their geomorphological evolution that is, driven by recent relevant uplifting. The use of lineaments as discontinuities to simulate fracture networks at different scales is allowed in the study case, in view of their geometrical similarities with geological structures.