184 



THE ROYAL SOCIETY OF CANADA 



Baffin 



Figure 2 



Area involved in the Jurassic-Lower Cretaceous subsidence (shown by vertical 

 ruling) and area involved in the Upper Cretaceous subsidence (shown by horizontal 

 ruling). 



which cuts across and truncates the anticlinal ridges of Devonian 

 and earlier sediments. The Tertiary occupies a depression east of 

 this fault or shear plane. The determination of the age of these 

 Tertiary beds depends mainly on plant remains. The correlation 

 made by Sir William Dawson with the Lignite Tertiary of the Plains 

 (the Fort Union of the Cypress Hills and the Porcupine Hill beds) 

 was based on a large range of specimens collected by R. G. McConnell 

 in 1888.^ If the age should prove to be Late Eocene the northern 

 and southern mountain building periods may be brought closer 

 in time, but cannot be synchronized as the structure does not coalesce. 



lAnn. Rep., Vol. IV, 1888-89, p. 980. 



