Three-dimensional reconstruction of the Carrara Syncline (Apuane Alps, Italy): An approach to reconstruct and control a geological model using only field survey data

This paper presents an approach to reconstruct geological structures in three dimensions using and honouring field survey geological data. The methodology was developed to reconstruct the poly-deformed Carrara Syncline (Apuane Alps, Italy) in order to better understand the relationships regarding the structural geology of the area and the hydrogeological fluxes.In the first step, all the geological data (observed, measured and interpreted) of the study area were organized in a database using a geographical information system. The standard tools of a computer-aided design (CAD) environment were used to build geological profiles using the observed data (outcropping contact lines) extracted from the database, as well as, to create the contact surfaces via interpolation using non-uniformal rational B-spline surfaces. The intersection lines between each of these surfaces and the digital elevation model yield the model contact lines (MCLs). Discrepancies between the MCLs and the corresponding outcropping contact lines were analysed to further constrain the surfaces of the model. Starting from these surfaces, a voxel-based solid model was built, for storing and displaying each rock formation.