Figure 3. Structural contour map, on base of Upper Pennsylvanian Kansas City Group, of the area encompassing the Nemaha Zone. Also at this level, the Nemaha zone had minimal structural effect on the regional west-dipping homocline. Contours in Kansas, Oklahoma, and Nebraska modified from Burchett et al. (1981). Nemaha fault trace in Kansas adapted from Berendsen and Blair (1992).