UPPER CRETACEOUS. 



691 



Of the formations Shaw writes as follows: 



The coal-bearing rocks described above are unconformably overlain by Tertiary and Qua- 

 ternary formations. The White River, a Tertiary formation of white sandy clay and conglom- 

 erate, covers a considerable area in the southeastern part of the field. It is spread over parts 

 of all the older formations, and is even found high up in the fountains. The so-called Chalk 

 Buttes, 3 miles southwest of Douglas, are also composed of Tertiary rocks, and the outcrop of 

 similar rocks extends westward for 25 miles along the foot of the mountains. 



L 13^14. SOUTH AND NORTH DAKOTA. 



A representative section of the Cretaceous of the Great Plains northeast of the 

 Black Hills is given by Darton.^'*' 



Generalized section [of Cretaceous] for tJie Belle FourcTie quadrangle, South. Dakota. 



Leonard ^'^ recognizes in the Upper Cretaceous of North Dakota the Laramie, 

 Montana (Fox Hills and Pierre), Colorado (Niobrara and Benton), and Dakota. 

 He describes the strata in detail, but they present no special peculiarities. 



In a later discussion of this area *^^ Leonard refers the Laramie of his previous 

 report to the Lance and Fort Union formations and says concerning the strata of 

 the Lance formation that " they have the same stratigraphic position as the Laramie 

 formation, with which they correspond in whole or in part." 



