Kriging

During post-processing, a file called astrape_extended_data.xyz is generated. This file can be used to convert 2.5D data into a 3D model using kriging in Oasis Montaj. To open and view this file, you need to import it into a Geosoft database file (GDB). Please refer to this guide for detailed instructions on importing the data.

Once the inversion model has been imported, you can convert the 2.5D data to a 3D model by performing 3D Kriging. The kriging functionality is located under the Voxel tab:

Choosing the appropriate kriging parameters is crucial for the accuracy of the 3D model. It is recommended to consult with a geophysicist or geostatistician to determine the best parameters for your specific dataset. We suggest performing kriging on the “Log10_Conductivity_mSm” column.

Ensure that the blanking distance is large enough to cover the distance between the survey lines. For example, if your survey lines are 100m apart and you are performing kriging with a cell size of 10m, make sure the blanking distance is at least 10m.

The strike, dip, and plunge parameters for the kriging should be selected based on the geological context of the survey area. Typically, the strike angle is set perpendicular to the survey lines with a strike weight of 2.0 to ensure the kriging is biased in the direction perpendicular to the survey lines.

For more detailed information on kriging parameters and how to interpret the results, please consult the Oasis Montaj 3D Kriging documentation.

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Clipping the 3D Model

After performing kriging, you may need to clip the resulting 3D model along the topography or a specific depth. Please see the clipping guide for instructions on how to clip the 3D voxel using a grid in Oasis Montaj.

If you need to generate a grid from the topography data to use as a clipping surface, please refer to the grid generation guide for more information on creating grids in Oasis Montaj.