64 
THE GEOLOGIST. 
THE OKDSH OF THE E0CK3. 
First Period. 
PRIMARY 
of authors. 
AZOIC— A (Gr.) without; Zoe, 
life : from the presumed ab- 
sence of organic remains. 
(The old authors included Granite, 
Slates, and the multifarious rocks 
called " Grauwacke," under the term 
Priaaary.) 
PALEOZOIC— Palaios (Gr.) old; 
Zoe, life. 
GROUPS. 
Oldest sedi- 
mentary rocks. 
Harleck grits, 
Longmynd flags 
and schists. 
Lower Silurian 
or Cambrian. 
Upper Silurian. 
Devonian. 
Carboniferous. 
VPermian. 
Second Period, j ^T^gozQIC-Mesos (Gr.) ; 
SECONDARY r, 
of authors. ' 
Triassic. 
Liassic. 
Oolitic or Juras- 
sic. 
Wealden. 
Cretaceous. 
Third Period. 
TERTIARY 
of authors. 
Eocene. 
CJENOZOTC— Kainos (Gr.), new ; ] 
Zoe, life. 
Lower Pliocene 
Pleistocene or 
Upper Pliocene. 
Fourth Period 
RECENT. 
In part Quarter- 
nary of some 
authors. 
Includes all rocks, volcanic or 
sedimentary, formed since the 
creation of man. 
Gaudaloupe 
limestone. 
Modern shell- 
sandstone. 
Travertin. 
Tufa, &c. 
Vegetable Soils. 
(To he Continued.) 
