Search Parameters

Data Search ellipsoid parameters offer axis orientation modes for regular geological information such as Strike, Dip, and Pitch, or for the geostatistical model axes generated from semi variogram modelling.

Open an existing Data Search form set

  1. Select any 3D interpolator, such as Inverse Distance Weighting on the Block Model tab, in the Estimation group.
  2. Right-click the embedded Data search form set and choose Edit from the pop-up menu.
  3. Select the Ellipsoid Properties tab to display the new parameters.

    4. An existing Data Search form set will always open in Rotations mode.

Create a new Data Search form set

Using rotations

Rotations mode provides the simplest way to set up a search ellipsoid, needing only the plunge and azimuth of Axis 1 and the rotation of Axis 2. If plunge is zero, the rotation of Axis 2 is equivalent to dip, although it can be either positive or negative. Rotation does not equate to dip if plunge is anything other than zero.

  1. Set Axis Orientations to Rotations.
  2. Enter the Azimuth and Plunge of Axis 1, and the Rotation of Axis 2.
  3. The application will then calculate the orientation of Axis 3.

    4. Rotation is measured from horizontal, looking in the direction of Axis 1. A positive rotation is anticlockwise (downward to the left) and a negative rotation is clockwise (downward to the right).

Using geological orientations

If you know the strike and dip of your orebody and have measured the pitch of lineations within it, you can use Geological (pitch) mode to create a matching search ellipsoid.

To set up a search ellipsoid in Geological (pitch) mode:

  1. Set Axis Orientations to Geological (pitch).
  2. Enter the Strike and Dip of the orebody, and the Pitch and Sense of the lineations.
  3. The application will calculate the orientations of Axes 1 through 3.

    4. Alternatively, if you already know the plunge and azimuth of lineations within your orebody, use Geological (plunge) mode instead.

To use Geological (plunge) mode:

  1. Set Axis Orientations to Geological (plunge).
  2. Enter the Strike and Dip of the orebody, and the Azimuth and Plunge of the lineations as Axis 1.
  3. The application will confirm that the Azimuth falls within the plane of the orebody, and then calculate the orientations of Axes 2 and 3. It will display a warning if the Azimuth is incorrect.

    4. In Geological mode the main axis of the ellipsoid (Axis 1) always lies parallel to the lineations, Axis 2 lies at right angles to Axis 1 (within the plane of the orebody), and Axis 3 at right angles to Axes 1 and 2.

Using geostatistical orientations

If you have modelled semi variograms and already know the azimuth and plunge of all three axes, use Geostatistical mode to create a matching search ellipsoid.

  1. Set Axis Orientations to Geostatistical.
  2. Enter the Azimuth and Plunge of Axis 1, and the Azimuth and Plunge of Axis 2.
  3. The application will confirm that Axes 1 and 2 are perpendicular and then calculate the orientation of Axis 3. It will display a warning if the Axes 1 and 2 are not perpendicular.