Time-table for North America. 



25 



GEOLOGIC CHRONOLOGY FOR NORTH AMERICA. 



(i) Classification based on Superposition of Strata, and Erosion Intervals. 

 Correlation by Means of Fossils. 



Eras 



° 3 



0«< 



Major 

 Divisions 



Periods 



New Periods 



Epi-Paleozoic Interval 



Late 

 Paleozoic 

 or 

 Carbon- 

 iferous 



Middle 

 Paleozoic 



Early 

 Paleozoic 



Permian 



Pennsylvanian 



Mississippian 



Devonian 



Silurian 



Ordovician 



Cambrian 



M 



Tennesseian 



Waverlian 



Cincinnatian 



Champlainian 



Canadian 

 Ozarkian 



Croixian 



Acadian 



Waucobian 



Advances in Life 



Extinction of ancient 

 life 



Rise of land verte- 

 brates 



Rise of modern insects 

 and ammonites 



Periodic glaciation 



Rise of primitive 

 reptiles and insects 



Rise of ancient sharks 



Rise of Echinoderma 



Rise of amphibians 

 First known land 

 floras 



Rise of lung-fishes 

 and scorpions 



Rise of land plants 

 and corals 



Rise of armored fishes 



Rise of nautilids 



Rise of shelled 

 animals 



Dominance of 

 trilobites 



First known marine 

 faunas 



Dominant 

 Life 



AGE OF 



AMPHIB- 

 IANS 



AND 



LYCOPODS 



AGE OF 

 FISHES 



AGE OF 



HIGHER 



(SHELLED) 



INVERTE- 

 BRATES 



