A geological model forms the foundation of the mining value chain, upon which all resultant assumptions are based – from initial target delineation to Mineral Resource estimation to final reserving and metallurgical processing.
The importance of a high-quality geological model cannot be stressed enough.
The importance of reviewing Geological Data at Mining Sites
Reviewing and incorporating all available data (historical and recent), as well as geophysical surveys and mapping data allows a geologist to form a well-rounded understanding of a project’s geology at a conceptual level, even during the early exploration stage, before drilling has begun.
Geological understanding is key to generating comprehensive and suitable exploration strategies which are supportive to the generation of a meaningful geological model.
Determining the sequence of orebody formation through deposition/erosion or intrusion, structural deformation and understanding the mineralisation controls, promotes good geological interpretation.
Regular updates and integrating new information allow solid geological theories to be tested and proved, revised and remodelled.
Often geologists do not dedicate enough time to building a high quality, representative and detailed geological model and frequently assume (sometimes incorrectly) that geostatistical solutions will partially, or even completely provide an adequate estimate of the spatial variability within the mineral deposit, resulting in simplified grade shell models being produced which do not adequately mimic the geometry of a mineral deposit.
Domaining within a geological model is critical to the Mineral Resource estimation process. Exploratory data analysis can assist in recognising domains. If controls on mineralisation are well understood, a wealth of information in the form of alteration, weathering patterns and structural trends may be also used to define these zones, in addition to lithological information.
Delineation of mineralised zones based on grade shells alone may often result in under- or over-reporting of the Mineral Resource. A meaningful estimate should be calculated within homogenous mineralised zones that display similar geological as well as statistical characteristics.
Geological models & Geostatistics
Geostatistics should confirm, rather than dictate, the interpretation of the geological model and defined domains within the geological model. A high-quality geological model combined with industry standard geostatistical methodologies will most often result in a credible, meaningful Mineral Resource estimate in terms of both the grade and tonnage for conversion to a Mineral Reserve.
A meaningful geological model improves the confidence in a Mineral Resource estimate. Mineral Resource classification should be a function of data density, grade continuity and grade estimation. However, confidence in geological input, data quality and geological continuity will always outweigh or override statistical classification methodologies during final Mineral Resource categorisation.
A high-quality geological model implies good understanding of geological concepts and resultant geological continuity and can serve as a strong support to classify the Mineral Resource at a higher level of confidence. A high-quality geological model should also support future expansion of exploration activities, potentially increasing the life of a project.
VBKOM – Geological Consulting Services South Africa
The VBKOM geology team are experienced in generating detailed geological models utilising both traditional and implicit modelling methodologies. Our models incorporate diverse exploration, geological, sampling, geophysical and topographic data for high quality Mineral Resource and Mineral Reserve reporting. We strive to generate purpose-built models using well-considered modelling processes and appropriate software selection.
We place high emphasis and pride on geological understanding, resulting in high quality, meaningful and useful geological models. We aim to provide our clients with a geological model that may be validated in terms of both hard data and experienced interpretation.
Should you wish to learn more about our geological modelling service offerings please contact us.