Post-Tertiary and Recent. 

 - Pliocene. 



Miocene. 

 --- Eocene. 

 Cretaceous. 



- Jurassic or Oclitic. 



Triassic (Kew Red Sandstone). 

 . Permian. 

 - Carboniferous. 



. Devonian or Old Red Sandstone, 

 .. Silurian. 



jr^i---- Cambrian. 



.... Huronian. 

 .... Laurentian. 



i 



FIG. 1. IDEAL SECTION OF THE CEUST OF THE EAKTU. 



