Deposit modeling is the construction of a quantitative, three-dimensional mathematical or computerized representation of a mineral deposit that captures its geological structure, mineralogy, grade distribution, and spatial variability. It is an essential tool in modern mining that underpins resource estimation, mine planning, production scheduling, and grade control across all commodities, including bauxite, gold, iron ore, and diamonds. The process of deposit modeling typically begins with the compilation and validation of geological and assay data from drilling programs, trenching, mapping, and geophysical surveys. Geological modeling involves the creation of wireframe solids that represent ore domains, lithological units, alteration zones, and structural features within a three-dimensional coordinate system. These geological wireframes define the spatial envelopes within which grade interpolation is performed. Grade modeling uses geostatistical techniques — most commonly ordinary kriging, indicator kriging, or multiple indicator kriging — to estimate the grade of the target mineral at unsampled locations across the deposit. The resulting block model assigns grade, tonnage, and density values to three-dimensional blocks of rock within the modeled volume, forming the basis for resource classification in accordance with reporting codes such as JORC or NI 43-101. In bauxite deposit modeling, the key variables include aluminium oxide (Al₂O₃), reactive silica (SiO₂), and total moisture. In gold deposit modeling, the primary variable is gold grade in grams per tonne. In iron ore modeling, key variables include iron (Fe), silica (SiO₂), alumina (Al₂O₃), and phosphorus (P) content. In diamond modeling, diamond content (carats per hundred tonnes) and stone size distribution are the primary grade variables.
