496 



THE TERTIARY PERIOD 



Iceozoic was substituted for Primary, as was Mesozoic for Secondary, 

 though the latter term is still used, especially in England. The 

 name Tertiary has thus lost its meaning, but is nevertheless 

 retained as a division of the Cenozoic group or era. 





Gulf Border 



Interior Region 



Pacific Border 



Pliocene 

 Series 



Floridian Stage. 



Blanco Stage. 

 Goodnight Stage. 



Pliocene 

 (Merced Series) 



Miocene 

 Series 



Chesapeake Stage. 

 Chipola Stage. 

 Chattahoochee Stage. 



LoupForktNebraska Substage. 

 Stage. (DeepRiverSubstage. 

 John Day Stage. 



Miocene 



(Auriferous 



gravels) 



Oligocene 



? 



White River Stage. 



? 



Eocene 

 Series 



Upper; Vicksburg. 



Uinta Stage. 



Tejon Series 



f Jackson. 

 Middle < Claiborne. 



1 Lower Claiborne. 



Bridger fBridger Substage. 

 Stage. ( Wind River Substage. 

 (Green River) 



Lower 1 Li § nitic - 

 ( Midway. 



Wasatch Stage. 

 Puerco. ? Fort Union. 



The great revolution which closed the Cretaceous and inaugu- 

 rated the Tertiary has left its effects visible in all the continents, 

 but the gap between the two periods is not everywhere the same. 

 This revolution gave to North America nearly its present outlines, 

 in consequence of which marine Tertiary beds occur only along 

 the borders of the continent, while the Tertiary of the interior is 

 all of fresh-water origin. In other continents, and especially in 

 Europe, the distribution of land and sea was very different in the 

 Tertiary from what it is now, and the topography of the land was 

 profoundly altered in the course of the period. Some of the 

 highest mountain ranges of the earth were upheaved in Tertiary 

 times, such as the Atlas, the Alps, the Caucasus, and the- Hima- 

 layas. That Tertiary ranges are high is not due to any extreme 

 degree of compression as compared with that which produced 



