These areas are then joined by extending certain contours with values nearest 

 those of scattered datum points located between the detailed areas, as shown 

 by the dashed lines in the figure. These lines form the skeleton of the map, and 

 it is a simple matter to fill in the remaining contours. 



It is sometimes possible correctly to infer the presence and magnitude of a 

 fault by working according to the principles just outlined. In A of Figure 24-13 

 an anomalous dip is indicated on the east flank of the anticlinal nose. Both dips 



Figure 24-13. Examples of simple and interpretative contouring of the same data. 



467 



