Characterising fold geometries from structural data: application to implicit modelling

Folds present a challenge for implicit interpolation because the information associated with the geometry of the structure is not explicit in the orientation of the folded foliation. Traditional implicit approaches involve interpolating between observations from orientation measurements and stratigraphic contacts. To constrain the geometry of folds, the user is generally required to draw fold profiles on cross sections or level maps using bedding structural elements. A new method allows for more structural elements (e.g. foliations, intersection lineations) and overprinting relationships to be incorporated into the modelling process.  Each generation of folding is successively modelled, starting with the most recent folding event. At each stage, several scalar and vector fields are interpolated to represent the axial surfaces, the fold axis and vergence of each fold. The geometry of each fold generations are defined by structural parameters. These parameters need to be derived from available data and specified to the interpolator. We present an adaptation of geostatistical tools to structural geology for quantifying fold geometry.