30 



THE WHITE RIVER BADLANDS 



posits has perhaps never been more vigorous nor better 

 planned than it is at the present time. Each succeeding 

 year enhances the quality and importance of the investiga- 

 tion and doubtless this will continue for many years to 

 come. 



Figure 5 — North America during the time when the Pierre (Cretac- 

 eous) shales in the form of mud were being laid down in the 

 sea. Schuchert, 1908. White represents land areas; diagonal 

 lines Pacific and Atlantic ocean areas; horizontal lines Arctic 

 conditions; vertical lines Gulf conditions; black represents for- 

 mation outcrops. 



