50 



EARTH FEATURES AND THEIR MEANING 



the first representing a pitching anticline and the second a pitch- 

 ing syncline. In both these reciprocal cases the strikes of the 



FIG. 31. Combined surface and sectional views of a plunging anticline (after Willis). 



beds undergo the same changes, and the dip directions serve to 

 distinguish which of the two structures is present in a given case. 

 There is, however, one further difference in that the hard layers 



Fio. 32. Combined surface and sectional views of a plunging syncline (after Willis). 



