Abstract: A method of transforming an input stratigraphic grid SGrid which represents a region including one or more geological discontinuities is now disclosed. At least one target cell that is local to one or more geological discontinuities is transformed by displacing at least one target vertex of the target cell of the input SGrid in a selected direction that: i) is selected to approximate a local tangent of the reference horizon; and ii) is oriented from the target vertex to a representative manifold representing one of the geological discontinuities and/or an intersection between two or more of the geological discontinuities. A magnitude of a displacement by which the target vertex is moved is determined according to a non-Euclidian distance between the target vertex of the target cell of the input SGrid and the representative manifold.