334 F. H. KNOWLTON CRETACEOUS-TERTIARY BOUNDARY 



bearing and plant-bearing beds appear to rest on marine beds perhaps as 

 old as the Mancos, the Laramie, so far as known, being absent. The flora 

 in these beds, although small, is undoubtedly the same as that in the 

 "Upper Laramie" near Carbon. Dinosaurs have not been found in Xorth 

 Park, though they are abundant in the beds in Carbon County, Wyoming. 



The flora of the ^'Tipper Laramie" in Carbon County embraces about 

 70 species, of which number nearly one-half are common to the Lance of 

 other areas, and there are also large unworked collections that will prob- 

 ably still further augment the number of common species. As already 

 indicated, five or six of these species are known in the underlying "Lower 

 Laramie." 



We have now come to the consideration of the flora of the Lance. I 

 have already shown that the Lance formation is inseparable — ^structurally 

 and lithologically — from the overlying Fort Union, and the flora is like- 

 wise so markedly of Fort Union facies that it is often quite impossible to 

 distinguish the one from the other without stratigraphic or other data. 

 As the Tertiary age of the Fort Union is admitted by every one, it is not 

 necessary to dwell on this point. It has a large flora of perhaps 500 

 species, many of which are still undescribed. 



The Lance flora embraces about 100 named and described species, as 

 well as a considerable number not yet described. Of these 100 species, over 

 75 are typical Fort Union species that have never l)een found in older 

 beds and most of them only in the Fort Union. I am, of course, well 

 aware that statistics may mean little or much, depending on how they are 

 compiled — that is, the mere presence of a species in a list may have little 

 significance or real value. In the present case, however, many of these 

 Lance species are found at dozens of localities and often in hundreds of 

 individuals. To any one familiar with the Fort Union flora, its prepon- 

 derating element in the Lance flora is apparent. 



The evidence regarding the post-Cretaceous floras has now been pre- 

 sented for the vast area which extends from New Mexico to Alberta. It 

 has been shown that in the south the Eaton formation is to be correlated 

 with the marine Eocene of the Gulf region, and step by step the correla- 

 tion through the Dawson, Denver, and Lance has been traced until it 

 merges inseparably with the Fort Union, which is of acknowledged Eo- 

 cene age. 



DiASTROPHIC EjIDENCE 



I had hoped to be able to present certain diastrophic evidence, which I 

 consider of the highest importance, if any serious attempt is to be made 

 in settling the Cretaceous-Tertiary boundary, but it has been deemed 



