The importance of the Validation of the Block Model Estimation with GEOVIA GEMS: GRAPHICAL VALIDATION.

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When estimating a block model, no matter what interpolation method is chosen, it is essential to validate the obtained results in order to ensure the estimation process quality according to the current industry standards.

By validating the block model, we look for:

  • That the estimation be globally unbiased
  • Minimize local bias
  • Keep the estimation smoothing at a reasonably acceptable level


There are numerous methods to do this and through upcoming blogs we will discuss these three (3):

  1. Graphical validation.
  2. Statistical validation.
  3. Swath Plot validation.

First, we will explain the method of Graphical Validation:




Evaluate in a global and visual way, the coherence and similarities between the estimation (block model) and the real data (composites).


How to do it?

Perform a visual inspection by plans and vertical sections of the estimated blocks and of the composites.


Care to take into account at the execution:

  • Composites need to have the same support as the size of the blocks
  • Use the same color code to display blocks and composites
  • Perform the analysis only on the best estimated blocks, e.g., those that are candidates to be measured and indicated resources


Expected results:

  • That the blocks represent the trend or expected anisotropy of the orebodies.
  • Similarity and coherence in grade distribution of the estimated blocks with respect to the composites.


This review is subjective but very useful to detect rough problems of over or underestimation or else errors in the grade anisotropy definition. The figures below highlight this process:



Figure 1: Graphical Validation – Plan View



Figure 2: Graphical Validation – Vertical Section EW



Figure 3: Graphical Validation – Vertical Section NS





Maria Angelica Gonzalez

María-Angélica is a Mining Engineer with a Diploma in Geostatistics and she is a candidate for a Master of Science mention Geology. She is registered as a Competent Person with the Qualification Commission of Competencies in Resources and Mining Reserves of Chile. She started her professional career in 1999 and has worked in consulting and project operations for diverse types of mineral deposits, performing the geostatistical evaluation of elements of economic interest as well as geometallurgical and contaminant variables. She is experienced in metallic and non-metallic projects, such as copper, gold, silver, molybdenum, iron, zinc, lead, titanium sands, phosphates, carbonates, iodine and nitrates, both in America and in Africa. Her current position is Senior Services Manager of Dassault Systèmes Chile (GEOVIA), serving the Mining Industry in Latin America. She is in charge of both consulting and training as well as technical sales, mainly in the technical and administrative leadership of projects. Previously, she worked as Leader of Geology and Resources of the Consulting Group at AMEC. AMEC International Ingeniería y Construcción.

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