STRATIFIED ROCKS. 



189 



reverse (Fig. 104). In gently folded strata it is very 

 common, to find the configuration reversed on the surface, 



FIG. 104. 



i. e., synclinal ridges and anticlinal valleys. Examples 

 of these are given on page 248. 



Folded strata, which are tilted only by folding, will 

 outcrop on level ground in parallel bands, as in Fig. 105, 



FIG. 105. 



which is a map view of Fig. 102. But if the whole be 

 again tilted in a direction at right angles to the folds, 



FIG. 106. Section of undulating strata. 



then the map of outcrop will be sinuous. Fig. 106 is a 

 section of folded strata thus tilted, and Fig. 107 is a map 

 of the same. The section is along the line CD. Exam- 

 ination of the signs of dip will explain the map. 



