TABLE II 



TIME SCALE OF NORMAL GEOLOGY : AGE AND DURATION OF ERAS AND 

 SYSTEMS (or epochs) SINCE THE BEGINNING OF THE PALEOZOIC 



(from Kulp, 1960) 



Era 



o 



50 



100- 



U 



O 

 N 



150|- O 

 to 



UJ 



200 



250 



300 



350 



400 



450 



500 



600L 



U 



N 



o 



LU 



Period 



Epoch 



Beginning or 

 epoch in my 



Quaternary 



Pleistocene 



1 



Cretaceous 



Jurassic « 



Tnassic 



Upper (Base of Santonian) 90 



Middle (Base of Albian) 120 



Lower 135 



Upper (Base of Callovian) 150 



Mfddle (Base of Bajocian) 170 



Lower 180 



Upper 200 

 Middle 



Lower 220 



o 



l_ 

 0) 



c 

 o 

 X) 

 1_ 

 nj 

 U 



Permian 



Pennsylvanian 



Mississippian" 



Devonian 



Silurian 



Ordovician 



Upper (Base of Ochoan) 235 



Middle (Base of Guadalupian) 250 



Lower 



270 



50 



100 



-150 



200 



250 



Cambrian 



Upper (Base of Missourian) 



Middle (Base of Desmoinesian) 



Lower (Base of Namurian) 320 



Upper 



Middle 



Lower 350 



Upper 365 



Middle 380 



Lower 400 



Upper 



Middle 



Lower 430 



Upper 

 Middle 



Lower 490 



Upper (Base of Crolxian) 510 



Middle 540 



Lower (600) 



300 



350 



400 



450 



-500 



600 



