Consulting companies often receive Mineral Resource models for review or updating and are readily faced with the dilemma of how to go about their work. As a geologist, one should look at the lithological logs, and facies zones as described by the geology section in the Technical Report, and be able to trace these discussions right through the entire modelling process, through to the end-result Mineral Resource Statement. Many times this is not possible to do.
Pure “grade shells” from drillhole data may sometimes coincidentally be close to the truth, however, very often, these models are poorly constrained due to poor understanding of local geology and may result in gross overor under-estimation of a Mineral Resource.
Companies should wish to present the most accurate Mineral Resources to the market; numbers which are defendable, depict integrity and that would withstand peer review by geologists and resource geologists alike. In addition, Companies spend a fortune on generating Mineral Reserves, thus their integrity and the basis for their declaration should be sound.
High quality geological modelling results in a good understanding of mineralisation mechanisms, excellent constraining for mineralisation envelopes, correct geometrical Mineral Resource estimation, resulting in a high quality Mineral Resource estimate which would deliver a high quality Mineral Reserve.
“If you do not understand your orebody, how can you mine it effectively?”
Geological models should honour lithological boundary changes and/or geological structures. In addition, they should present an interpretation of visible, mappable characteristics for a specific orebody, which is based on a core of real geological data from geological mapping and geological drillhole logging. Any interpretations and projections beyond the informed limits of a geological model should honour exactly the same principles as those utilised in generating the original core model. They should also honour topographical surfaces when exposed at surface.
Geostatistics and grade shell modelling has often been used to short cut the Mineral Resource estimation process, especially in the case of shear-hosted or stockwork precious metal deposits or massive or porphyry base metal deposits. This is often done to the medium and long-term detriment of the Client. These models may present “quick solutions” but often result in expensive mistakes. Mineral Resource models based purely on geostatistical grade shells often result in the incorrect interpretation of significant grade trends and orebody trends, resulting in a flawed estimate, with the result: You will plan to mine in the wrong places, with enormous cost to the company. If you do not understand the geology, you do not understand the grade distribution. If you do not understand the grade distribution, you cannot create an accurate business plan. This is often where companies flounder because their models inaccurately portray where the grade is located and they make
incorrect assumptions with regards to mining selectivity, resulting in poor business decisions with regard to
mining methods and required mining equipment.
Real geological models pose an asset to any mining or exploration company, as they impart a close to real depiction of what the orebody will look like and how the internal grade will be distributed. Grade will be correctly constrained, Mineral Resource models will be built on a defendable basis, resulting in a high quality Mineral Resource estimate. This will eventually result in high quality Mineral Reserves, upon which sound business decisions may be made. Minxcon has developed the expertise to generate high quality geological models for exploration and Mineral Resource estimation purposes and is more than capable of assisting companies to get high quality geological models in place for most commodities.