= Solution
The <reverse fault> requires strong east–west compression; the vertical opening <geological joints> require the least <principal stress> in the <effective stress> tensor east–west. \b[They need not have formed at the same time or under the same local <stress> field.] Compression can form the <reverse fault> during burial and <crustal shortening>; subsequent <tectonic exhumation>, unloading, relaxation, cooling or another tectonic episode can rotate the <principal stress> ordering and permit opening <geological joints>.
Furthermore, local <stress> near <faults>, layer interfaces and topography can differ from the regional <stress>. A high <pore pressure> shifts every <Mohr circle> left by $p$, helping <tensile failure>, but isotropic <pore pressure> alone cannot exchange the east–west and vertical <principal stress> ordering. Determine relative timing using cross-cutting relations, offsets of <geological joints>, and any generations of fracture-filling <minerals>. Spatial coexistence is therefore evidence of a deformation history, rather than a requirement that the two failure diagrams describe one simultaneous homogeneous <stress> state.
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