1 82 KNOWLTON 



Heer to be of this age from the mouth of the Mackenzie River, in 

 Greenland, Spitzbergen, and various European localities. Doctor 

 Newberry was led to refer them to the Miocene. Subsequent events 

 have shown, however, that the position assigned the above mentioned 

 beds by Heer was too high, and as a consequence it has come to be 

 recognized that the Fort Union beds are beyond question of Eocene 

 age. This result, however, was not reached without much diver- 

 sity of opinion and conflict of authority. 



It is largely to the efforts of Dr. J. S. Newberry that we are indebted 

 for keeping alive the question of the distinctness of the Fort Union 

 from the typical Laramie. From the beginning of his studies of 

 the Fort Union flora, until his latest utterance on the subject, he 

 insisted upon their separation. His last words concerning it are as 

 follows:^ 



Whether the Laramie is Cretaceous and the Fort Union Tertiary 

 are other questions, but they are certainly distinct from each other, 

 distinct in the general botanical facies of their floras as well as in 

 the absence of common species. That the Fort Union flora is Ter- 

 tiary there can be no reasonable doubt; it has many species in com- 

 mon with the recognized Tertiary in the Canadian provinces of 

 North America, in Greenland, and in the British islands, and it 

 contains some plants which are living at the present day. 

 Moreover, the grouping of the plants comprising it gives it a facies 

 which enables one to recognize it at a glance. The abundance of 

 species of Populas, Viburnum, and Corylus, imparts to it an aspect 

 as different from that of the flora of the Laramie as are the recent 

 floras of Europe and America from each other. 



That it is of Tertiary age is no longer seriously questioned. 



Areal Distribution and Lithologic Character of Fort Union 



Formation. 



The Fort Union formation, as now known, covers a vast area in 

 the central Canadian provinces and, as predicted by Doctor Hayden, 

 touches the Arctic Ocean in the valley of the Mackenzie River, while 

 to the southward it is the surface formation over much of the western 



' Trans. N. Y. Acad. Sci., vol. 9, 1889, pp. 30, 31. 



