Pole Vector Density Contour Plot

A Contour Plot is generated by selecting the Presets > Contour option from the Stereonet 2D or Stereonet 3D ribbons.

A Pole Vector Density Contour Plot is the main tool in Dips for analyzing mean and/or maximum pole concentrations. It is used to visualize the clustering of orientation data not immediately evident from a Pole Vector Plot. The contours represent statistical pole concentrations, calculated using the distribution method (Fisher or Schmidt) specified in the Edit Contour Data dialog.

Terzaghi Weighting

• If the Terzaghi Weighting is not applied to the Contour Plot (i.e., Apply Weighting = OFF), then the plot is a direct contouring of the pole orientation data as measured and recorded. No bias corrections are made to adjust for directional sampling bias.
• The Terzaghi Weighting option can be applied to the Contour Plot (i.e., Apply Weighting = ON) to account for the sampling bias introduced by orientation data collection along Traverses. The weighting applied to each pole is governed by the orientation and type of Traverse on which it was recorded. For example, a plane sub-parallel to a Traverse line or plane will be more heavily weighted than one perpendicular to the Traverse.

WARNING: If you use the Apply Weighting = OFF option, be sure you understand the physical significance of the correction before drawing critical conclusions based on its results. See the Terzaghi Weighting topic for details.

The Contour Plot range, style, etc., can be customized in the Contour Options dialog.