iio8 



PRLXCIPLES OF STRATIGRAPHY 



Thus names were derived, in part, from the age of the formation, in part, from their lithic 

 character and contents, in part from typical localities, and in part from former inhabitants of 

 typical localities. 



tions of the value of stages or substages, as in the following case: 



Hiatus and disconformity 



Upper Siluric or Monroan. 

 (Neosiluric) 



j Lucas dolomite 

 Detroit RiverJ Amherstburg limestone 

 Series ] Anderdon limestone 



[Flat Rock dolomite 



Hiatus and disconformity 

 Sylvania sandstone 

 Hiatus and disconformity 



{Raisin River series 

 Put-in-Bay series 

 Tymochtee shale 

 Greenfield dolomite 



Hiatus — disconformity 

 * Referring to the percentage of modern organisms present. 



