

LAND AND WATER 21 



The mountain chains whose main outlines we have just 

 traced, did not attain their high altitudes without producing 

 vast modifications in the level of the adjacent regions. In fact, 

 they rest upon enormous continental bases ; as a rule, they are 

 on the border line marking the separation of the continents of 

 one epoch from those of a preceding one, so that where the 

 continental barriers are missing, as along the American littoral 

 of the Pacific, we are led to think there once existed a continent 

 which has since disappeared. 



We shall now endeavour to reconstruct, on the basis of the 

 above principles, the distribution of the continents and oceans 

 at the various geological epochs. The first continents to emerge 

 from the seas, as has already been indicated, were arranged 

 in the Northern Hemisphere in two principal semi-circles, 

 of which the larger part has since then been submerged ; 

 the first constituting the Palaearctic continent was not very 

 far from the South Pole and the second near the Equator. 



The Circumpolar coronet x broke up into four massifs or 

 barriers arranged around the Pole like the petals of a flower : 

 1, the Canadian barrier in North America ; 2, Greenland ; 

 3, the Finno-Scandinavian barrier, including Scandinavia and 

 Finland; 4, the Siberian massif. They formed at first, no doubt, 

 a continuous half-moon, divided up by the sinking 

 of certain portions in a meridianal direction. Their 

 present distribution does not date back far beyond our own 

 epoch. These four massifs had already been subjected to 

 folding before any additional strata had been deposited upon 

 them. They may have been temporarily submerged, but they 

 have remained constant ever since the folding they underwent 

 precedent to the subsequent geological periods, so that all the 

 later deposits formed on their levelled surface have remained 

 horizontal. Their folding shows that they underwent a process 

 of corrugation at a very early period, resulting in the formation 

 of mountain chains which quickly lost all traces of relief. It 

 was these mountains, the oldest raised up on the earth's surface, 

 which formed the Huronian chain. 



Another continent extended from about ioo° W. long, to 

 165 E. long., roughly resembling a huge spitted bird with 

 folded wings (see Map II), with the equator representing the 

 spit, the head towards the East, and with a huge wattle 



1 IX, 486, Map I. 



