Modelling the Geometry of Geological Units and its Uncertainty.pdf

Modelling the Geometry of Geological Units and its Uncertainty in 3D From Structural Data: The Potential-Field Method 1 1 2 3 J P Chilès , C Aug , A Guillen and T Lees ABSTRACT The potential-field method was designed to build 3D geological models from data available in geology and mining Most 3D geological modelling tools were designed for the needs of the oil industry and are not suited to the variety of situations encountered in exploration, namely: other application domains. Moreover, the usual modelling tools are not 1. a geological map and a digital terrain model (DTM), able to quantify the uncertainty of the geometric models generated. The potential-field method was designed to build 3D geological models from 2. structural data related to the geological interfaces, data available in geology and mineral exploration, namely the geological 3. borehole data, and map and a DTM, structural data, borehole data and interpretations of the geologist. This method considers a geological interface as a particular 4. interpretations from the geologist. isosurface of a scalar field defined in the 3D space, called a potential field. The interpolation of that field, based on universal cokriging, It is not limited to sedimentary deposits and does not require provides surfaces that honour all the data. seismic data (such data would be useful but is seldom available Due to the difficulty of inferring the covariance of the potential field,