530 F. H. Knowlton — Study of the Coal-hearing Rocks. 



to be regarded as Cretaceous (Laramie) on account of its sup- 

 posed stratigraphic identity with the Laramie of the Denver 

 Basin. 



(2) In 1907 W. T. Lee detected the presence of a widespread 

 unconformity in the midst of this supposedly continuous Cre- 

 taceous section, the beds below the unconformity being named 

 the Vermejo formation, and those above the Raton formation. 



(3) The distinctness of these formations is abundantly con- 

 firmed by the paleobotany, since of the 106 Vermejo species 

 and 151 Raton species only four cross the line of the uncon- 

 formity. 



(4) The Yermejo formation is shown by the plants to be 

 Cretaceous (Montana) in age, being in the approximate position 

 of the Mesaverde. 



(5) The Raton formation is shown to be essentially of the 

 same geologic age as the Denver formation of the Denver Basin, 

 and of the Wilcox formation of the Gulf region, the latter 

 being indisputably of Eocene age. 



(6) The conclusion is therefore reached that the Raton and 

 Denver formations are Eocene in age, a confirmation of the 

 original contention of Cross as to the Denver. 



