Resource Geologists can now use Swath Plots in the latest versions of GEOVIA Surpac^TM for quality assurance and quality control to support block model validation within their software solution.

This refers to a comparison of sample data or drillhole composite data against the estimated values in the block model by generating swaths or slices in the orientation specified by the geologist (Northing, Easting or Elevation).

The Swath Plots functionality provides geologists performing geostatistical estimation with greater confidence in their estimation techniques. This is also one of the requirements of Mineral Resource reports and validation as per international codes for resource validation, for instance, Joint Ore Reserves Committee (JORC).

Here’s how you can generate Swath Plots using elevation ranges in Surpac 6.7.2 and 6.7.3.

1. In order to generate Swaths, you will need the drillhole composite file and a block model.

2. In the drillhole composite file, take note of the description field (Surpac D-field) that has the estimated values to be plotted.

3. Open the block model and run the block model summary to identify the attribute whose values have been estimated. In the screenshot below, the estimated attribute is gold and in the composite file it is saved in the D3field.

4. The image below shows the block model (in blue) with block faces switched off as well as the drillhole composite file (in white) opened in the graphics.

5. To create the Swath Plot, you will need to access the Swath Plot function. Click on Block Model > Geostatistics > Swath Plot. Below you can see the definition of inputs.

Under D-Field Parameters, enter the description field of the string file with values to compare with. For example, you may enter “Metal_Composite” (e.g. CU_Composite) for the Label which will be displayed on the chart for composite values. The Weighting can be left blank.

Under Block Model, specify the block model density attribute. You can also choose to constrain the Swath Plot generation with any block model attribute/surfaces/solids. Select the estimated attribute from the dropdown list and type any lable (e.g. CU_Estimated). This is the label that the chart will show for the estimated grade values.

Under Swath Options, choose the orientation of your chart. Commonly, users select the direction following the strike of the orebody or use the elevation for a downhole comparison. If using the elevation orientation, the minimum and maxium coordinates will be on the Z with the interval being bench height/ half bench. This varies from one deposit to the next.

Lastly, specify the output file which will have the data in a text format or web-based formats. Click Apply.

6. Constrain by grade >=0 in order to eliminate any negative grades that might exist in the block model.

7. The Swath Plot generates two outputs, one as Chart in the Block Model Basic Statistics dialog and another in your preferred format. Click Apply.

8. Your Swath Plot in the Basic Statistics Window should look like this:

9. Your Swath Plot data in user-selected format should resemble this:

Note that ideally, the two lines (Grade Composite line and Grade Estimated line) on the Swath plot should be on top of one another with no gaps in between. It is the discretion of the Geologist to determine their tolerance limit on the difference between the two values.

For more information on the new Swath Plot functionality in Surpac, check out Gaining Greater Confidence in Your Block Model Estimates.