PERIODS 



V- QUATERNARY :4000 



HIMALAYAS 

 SWISS ALPS 



PYRENEES 



EASTERN ALPS 

 (Partly) 







12660' 



i^fo! 



I I i I ! i i i , 



! }? w ' ! ! 



I ' I i '1300 



rr 



MI 



THEHERCYNIAN BELT OF 

 CENTRAL EUROPE? 



SCOTTISH HIGHLANDS. 



SILURIAN 



FINLAND 



E.SCANDINAVIA 



S.BOHEMIA 



15000 



ORDOVICIAN 



17000 



CAMBRIAN 



16000 



ALGONKIAN 



I ^ |Ty 



I ' i ' i 



i ! i i ! i i i , , , 



ipPfW i i 



i ! i ! i ! i ! i ! 1 1 1 



SILURIAN 



1 



ORDOVICIAN 



CAMBRIAN 



ROCKY 

 MOUNTAIN 



(LARAMIE) 



SIERRA NEVADA 

 PALISADE 



APPALACHIAN 



ACADIAN 



TACONIC 



ALGONKIAN 



ARCHAEAN 



? PRE-CAMBRIANT- 



? ARCHAEAN 



FIG. 7. Main divisions of geologic time. The notches at the sides of the scale rep- 

 resent chiefly the periods of mountain uplift in the northern hemisphere of the Old 

 World (left) and the New World (right). (From Osborn's " The Age of Mammals.") 



29 



