 Solution

The fault dips are approximately $90^{\circ }$. The mapped senses of fault slip are predominantly strike-slip faulting. In an Andersonian faulting regime, the intermediate principal stress ${\sigma }_2$ is vertical and the maximum and minimum principal stresses ${\sigma }_1,{\sigma }_3$ are horizontal, so the preferred fault planes are vertical. Local bends can introduce oblique-slip faulting without changing this first-order interpretation.