I/O Bulletin of Laboratories of Denison University. [Voi. xii 



etched out of the soft shale, penetrating to some extent the 

 harder and more resistant Knox dolomite. These features are 

 well developed in the vicinity of Cave Spring and are shown 

 again in the northeast corner of the map (Fig. 9). 



Fig. S. 



Scale of M/les. 



Topographical Map of the Cave Spring District, Georgia. (Topographic Sheet, 



Rome Folio, U. S. Geo/. Survey). Cont ur-interval, lOO ft. 



Scale, 0.5 in. = I mile. 



To the east of a line drawn through the town of Cave 

 Spring the area is underlaid by the Knox dolomite. Surface- 

 erosion is relatively slower over this part of the area, on ac- 

 count of the larger proportion of chert contained in the dolo- 

 mite, than in other parts underlain by softer and less resistaut 

 rocks. The surface is generally hilly and stands several hun- 

 dred feet above the valley-floors of softer rock. It forms a 



