64 



First Period. 

 PRIMARY 



of authors. 



THE GEOLOGIST. 



THE OEDEB OE THE KOCKS. 



GROUPS. 



AZOIC— A {Gr.) without ; Zoe, Oldest sedi- 

 life : from the presumed ab- mentary rocks, 

 sence of organic remains. Harleck grits, 



Longmynd flags 

 and schists. 



(The old authors included Granite, 

 Slates, and the multifarious rocks 

 called " Grauwacke," under the term 



Primary.) 



PALEOZOIC— Palaios (Gr.) old; ^ 

 Zoe, life. 



Lower Silurian 

 or Cambrian. 

 Upper Silurian. 

 Devonian. 

 Carboniferous. 

 ^Permian. 



Second Period. 

 SECONDARY 



of authors. 



Tliird Period. 

 TERTIARY 

 of authors. 



MESOZOIC— Mesos (Gr.) middle; 

 Zoe, life. 



Triassic. 

 Liassic. 



Oolitic or Juras- 

 sic. 

 Wealden. 

 ^Cretaceous. 



C^NOZOIC- 

 Zoe, life. 



Eocene. 

 Miocene. 



Pleistocene or 

 Upper Pliocene. 



Fourth Period ^ 

 RECENT. 

 In ]);irt Quarter-) 

 ii:iry ol' some 

 authors. 



Includes all rocks, volcanic or 

 sedimentary, formed since the 

 creation of man. 



Gaudaloupe 

 limestone. 



Modern shell- 

 sandstone. 



Travertin. 



Tufa, &c. 

 (^egetable Soils. 



XTo be Continued.) 



