3D implicit geomodelling applications in the metamorphic units of the Italian Western Alps (Aosta Valley, Italy)

@inproceedings{ARIENTI_RM2021,
 abstract = { In the context of the RESERVAQUA project, an Interreg Italian-Swiss programme, a multi-annual project of 3D geomodelling is being carried out. The study area has a huge extension of c. 1,000 km2 along the Swiss-Italian border to the North of Aosta. Almost the whole spectrum of metamorphic facies is covered by the outcropping units, belonging to the Austroalpine, the Penninic and the Helvetic domains. In such a complex and heterogeneous setting, developing a conceptual model is necessary in order to define the scale of the problem and what level of detail to give to the 3D model. Afterwards, an orientation statistics study has been performed on the structural data available with the aim of dividing the study area in subareas with similar mean foliation or folded along the same axis. This phase identifies homogeneous tectonic zones. Continuing with the actual modelling process, we faced the problem that no out-of-the-box interpolation algorithm is available for such a complicated tectonic setting with isoclinal folds, large volume variations of the lithological bodies, tectonic contacts between large-scale tectono-metamorphic units, thin tectonic slices, lenticular bodies, and many other complex geological geometries. To properly represent these entities using existing software (SKUA/Gocad in this case) and fit the very detailed geological maps available (mapped at 1:5.000-1:10.000 with a dense set of structural stations), it is sometimes necessary to “cheat” on their geological meaning. For instance, (1) tectonic contacts and lithological boundaries can be treated as unconformities (and not as the movement surfaces or conformal boundaries they are) in order to strictly divide different tectonic units or to allow thickness variations. In other scenarios, (2) a “fake” stratigraphy with repetition of the same lithologies could represent lenticular bodies or sequences of isoclinal folds. In this contribution, we give an overview of the modelling solutions adopted, according to their implementation and their ability to properly fit the previous geological knowledge about the study area. },
 author = { Arienti, Gloria AND Bistacchi, Andrea AND Monopoli, Bruno AND Dal Piaz Giorgio, Vittorio AND Dal Piaz, Giovanni AND Bertolo, Davide },
 booktitle = { 2021 RING Meeting },
 publisher = { ASGA },
 title = { 3D implicit geomodelling applications in the metamorphic units of the Italian Western Alps (Aosta Valley, Italy) },
 year = { 2021 }
}