A graphical device that plots the dip of a planar feature versus its depth. The Y-axis is depth and the X-axis (scaled 0°-90°, positive up) is the azimuth. Colours and shapes can be varied to distinguish different dip types and dip quality. Vertical change sin dip azimuth can be related to unconformities, faults and fold structures. These plots are usually produced in conjunction, and viewed side-by-side, with azimuth plots.