We propose a 3D modelling strategy of the encased mini-basin of Inceyol in Sivas (Turkey). The challenge lies in the combination of sparse outcrop data and the complex interpretive geometry of geological structures that comes from salt tectonics. We succeeded in modelling the convoluted salt surface using an explicit indirect surface patch construction method followed by a manual mesh improvement. Then, we modelled the mini-basin sediments with an implicit approach. The result highlights the remarkable geometry of the convoluted salt horizon and its associated mini-basin by extending in 3D the geologist's interpretive 2D sections. This case study proves that building complex geometries is feasible with the existing tools and a good expertise in the various geomodelling techniques. The work also underlines the need for new methods to ease the modelling of such tectonic features from sparse data. We propose a 3D view of the model thanks to WebGL technology, as well as downloadable data to constitute a reference case study.