Norman Heckscher^1^, Andrew Hughes^2^, Barry Saunders^1^ and Glynne Owen^3^
1.QGESS Pty Ltd, Brisbane
2.Golding Contractors, Brisbane
3.JB Mining Services, Brisbane
Inaccuracies in the stratigraphic models of coal deposits can result in significant financial losses and operational disruptions in the coal industry. The two common modelling approaches are using independent structural surfaces for roof and floor or stacking thickness grids from a reference surface. These approaches are adequate for the majority of coal deposits but display difficulties in representing the complex geological structures encountered in steeply dipping and folded coal deposits. These methods encounter challenges with conflicting control strings, inconsistent thickness representation, and the inability to accurately account for true stratigraphic thickness in the presence of dipping strata and non-vertical boreholes. This paper presents a novel stratigraphic modelling methodology by combining in-situ data, trigonometric calculations for true thickness determination, and Radial Basis Functions (RBFs) for smooth interpolation of thickness grids. Application of this approach to complex coal deposits has demonstrated improved reconciliation between scheduled tonnages and geological models. The findings suggest this methodology has the potential to enhance the accuracy and precision of coal volume estimation, contributing to more effective production forecasting and resource management in the coal industry.