= Solution
For an <Andersonian faulting regime> appropriate to the stated <normal fault>, take \b[$\sigma_1$ vertical, $\sigma_2$ north–south along strike, and $\sigma_3$ east–west]. Thus the minimum horizontal compression is normal to the fault’s north–south strike. In an east–up cross-section, draw $\sigma_1$ vertically and $\sigma_3$ horizontally, with $\sigma_2$ perpendicular to the page. These are plausible regional <principal stress> directions, rather than measured directions uniquely recoverable from one photograph.
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