266 STANTON 



which, while not specifically identifiable, are apparently of types that 

 elsewhere occur in the " Ceratops beds" and older formations. This 

 is the only locality in the region where dinosaurs have been found.^ 



The next higher formation in Barton's classification of the Dayton 

 quadrangle is the De Smet, which in its upper half contains the 

 principal coal beds mined at Monarch, Carneyville, Dietz, and else- 

 where in the region. The lower member beneath these coals is 

 described by Taff as "essentially all shale or ... . shaly 

 in character and prevailingly dull drab, bluish and brown in color, " 

 and has an estimated thickness of 2500 to 2800 feet. The upper 

 member, of approximately the same thickness in the area studied by 

 Taff, is lighter-colored and contains a larger proportion of sandstone 

 and coal. The fossil plants of both members belong to the Fort 

 Union flora according to Knowlton, and the invertebrates which have 

 been found only in the upper member are also Fort Union forms. 

 Attention is called to the fact that all the plants from this district listed 

 by Knowlton as lower Fort Union, except one small lot from near 

 Buffalo, which will be referred to again, are from the De Smet forma- 

 tion and the lowest of them are from several hundred feet above its 

 base. In other words they have nothing whatever to do with the 

 "Ceratops beds" which are without much doubt represented in the 

 Piney formation. 



Farther south in the Fort McKinney quadrangle and in the southern 

 part of the Dayton quadrangle the Kingsbury conglomerate has 

 been mapped between the Piney and De Smet formations, though 

 Darton^^ states that it probably develops out of the lower part of the 

 De Smet. Taff's work in tracing individual coal beds and associated 

 rocks led him to believe that the Kingsbury conglomerate is con- 

 siderably higher in the section. His observations are recorded^^ as 

 follows : 



A considerable part of the coal-bearing rocks change in character in 

 certain respects toward the south, in the general direction of the 

 strike of the beds. Near the State line, in T. 58 N., R. 86 W., cer- 



** Hatcher has reported horned dinosaurs east of the Bighorn Mountains 

 about 40 miles south of Buffalo, Wyoming, but nothing is known as to their 

 stratigraphic position. 



''Bald Mountain, Dayton folio (No. 141) Geol., Atlas U. S., 1906, p. 8. 



" Bull. U. S. Geol. Survey, No. 341, p. 131. 



