Implicit model creation for the application of geophysical inversion and forward modelling; drill target generation for undercover ore deposits
Résumé
Exploration for undiscovered uranium deposits within the Athabasca Basin, Saskatchewan, Canada is complicated by a thick sedimentary cover, masking the geophysical expression of the basement-sandstone unconformity interface that provides a favourable pathway and trap for mineralizing fluids. Zonal alteration associated with uranium deposition disrupting the regional distribution law of density and resistivity must be identified and parsed from the primary controls on the geophysical response; geological and structural form of the underlying strata. Provided a solid understanding of the geological context, these secondary disruptions can be identified and targeted for diamond drilling investigation through inversion processing of the geologic model.
A 3D block model of an exploration zone has been created through implicit modelling from sparse drill-hole data to aid in three-dimensional visualization, inversion modelling and resulting target optimization. When combined with an 'expert-driven' approach to data analysis regarding principal metallogenic guides within the geological context of the exploration area, identification of zones of physical property variation unaccounted for in the primary geological conditions can be used to vector towards zones of interest for improved drill targeting of deeply buried ore deposits.