EOSYS provides the following services on resource estimation:
- Collecting and compiling data (geological description, cross sections or plan maps,…)
- Setting-up of drillhole and sample databases to suit all information necessary to build a resource model including assay, geological (lithology, alteration, oxidation…) and geotechnical data.
- Construction of an interpretative geologic model that is one of the most critical factors in the resource estimation. These geologic models include host rocks, alteration types, structural characteristics, multiple phases of mineralization and post- mineralization features.
- Sample compositing in which sample assay data are combined by computing a weighted average over longer intervals to provide a smaller number of data with greater length for use in resource estimate.
- Computation of basic statistics and evaluation of grade distributions which are the first quantitative analyses of the grade data.
- Variogram modeling. The variogram is the fundamental tool used to measure spatial continuity of grade data.
- Resource estimation using kriging. Kriging is the geostatistical estimation method developed to provide the “best spatial estimate” for grade based data.
- Model validation by 3D visual comparison of block grades compared to composite samples. Calculation of kriging error grid (standard deviation of the estimate at each grid node).
- Resource estimations using many different cut-offs to determine the cut-off impact on the overall tonnage and on the average grade.
Surface and Subsurface data
Exploration target & average Cu vs Cu cut-off
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