FIGURE 34.

Two‐ways to prepare vertical sections from a region of interest. A plane parallel to the equator, the horizontal, can be chosen freely. The choice of the horizontal does not necessarily impact on the way in which sections are prepared. Slabs of the region of interest can prepared in the same way in (a) and (b) despite the choice of different horizontals. The choice of horizontal does impact on the way the slabs must be rotated prior to sectioning to generate the random angles that are necessary to ensure isotropy. Slabs or parts of them must be rotated around the vertical, an axis perpendicular to the horizontal [Color figure can be viewed at wileyonlinelibrary.com]