3 8 4 



HISTORICAL GEOLOGY 



The following table includes the more important divisions of the 

 geological record : 



[Era 

 Cenozoic I and 

 [ Group 



TEra 

 Mesozoic < and 

 [ Group 



Paleozoic 



Era 



and 

 Group 



f Period 

 ' Quaternary I and \ 

 [ System 



Recent 



Epochs 

 { and 



l Pleistocene i „ . 

 I { Series 



Tertiary 



f Cretaceous 

 { Jurassic 

 { Triassic 



Period 



and 



System 



Pliocene 

 Miocene 

 I Oligocene 

 { Eocene 

 Period and System 

 Period and System 

 Period and System 



Epochs 



and 

 Series 



Pre-Cambrian Eras 



Carboniferous Period and System 



Permian 



Pennsylvanian 



Mississippian 

 Devonian Period and System 



Silurian Period and System 



Ordovician Period and System 



Cambrian Period and System 



Proterozoic Era and Group 

 Archaeozoic Era and Group 



REFERENCES 



Grabau, A. W., — Principles of Stratigraphy, pp. 1073-1095. 

 LeConte, Joseph, — Elements of Geology, 5th ed., pp. 197-209. 

 Scott, W. B., — An Introduction to Geology, pp. 516-531. 

 Shimer, H. W., — An Introduction to the Study of Fossils, pp. 8-28. 



