This example has none to show you that it is still possible to produce a well informed cross-section just from outcrop patterns. In this case, we see that the outcrop bands on the south side of the fold are systematically wider than on the northeast side, indicating shallower dips on the south sides. Without actual dip data, the cross-section will be schematic rather than strictly quantitative, but it will still greatly aid in visualizing the structure. Even if you have dip data, it may be a good idea to do a schematic section first to get a grasp of the structure. Pitfalls of Dip Data Dip data is sometimes more misleading than helpful.
Beginners tend to draw long lines extending down the dip, then construct the structure from there.
On the scale of a typical map or cross-section, a dip measurement cannot be extrapolated more than a hair's breadth beneath the surface. The only requirement is that the structure be tangent to the dip measurement. A hundred meters below the surface the dip might be quite different. If the strike is oblique to the cross-section, you must use apparent dip rather than real dip. If attitude data are somewhat variable, use an average value rather than taking each measurement literally.