3D Modelling with Gocad of Complex Geological Structures in the Frontal Part of the Southern Alps

Cartographic geological and structural data stored in a GIS can be used for the semi-automatic reconstruction of geological bodies with complex geometric features. Establishing a link among GIS and GOCAD (Nancy, France), a powerful software for 3D modelling, it is possible to construct stratigraphic and tectonic surfaces taking into account any kind of geometrical constrain coming from surface geological data. Complex surfaces can be thus obtained through the use of large sets of bedding attitudes, superficial stratigraphic boundaries, faults and other structural elements such as fold axes and fold axial surfaces. This approach has been applied to Alpine tectonic structures developed in the frontal part of the sedimentary cover of the Southern Alps, Bergamo, Italy. Here large folds are related to thrust propagation within the sedimentary succession deposited in the Lombardian basin between Late Triassic and Cretaceous.