Morphotectonic reconstruction of the offset surface at Dark cloud creek site. a, orthophotograph, b, shaded map and c, profile curvature map. For clarity of representation, the color scale of the profile curvature map is saturated in gray for extreme values. Lines and circles are piercing lines and points used to measure offsets. Dashed lines are projections of piercing lines on the fault. Note that, owing to the curved geometry of the upstream riser, due to erosion, the piercing line is restricted to the part of the riser that aligns most closely with the direction of the drainage.