TIME AND CHANGE 



and, to account for the forty thousand feet of sedi- 

 ment deposited in Palaeozoic times in the region 

 of the Appalachians, he presupposes a neighboring 

 continent to the east, probably formed of Lauren- 

 tian rocks, where now rolls the Atlantic. But if 

 such a continent once existed, would not some ves- 

 tige of it still remain? The fact that no trace of it 

 has been found, it seems to me, invalidates Lyell's 



theory. 



Archsean time in geologic history answers to pre- 

 historic time in human history; all is dark and uncer- 

 tain, though we are probably safe in assuming that 

 there was more strife and turmoil among the earth- 

 building forces than there has ever been since. The 

 body of unstratified rock within the limits of North 

 America may have been much greater than is sup- 

 posed, but it seems to me impossible that it could 

 have been anything like as massive as the continent 

 now is. If this had been the case there would have 

 been no great interior sea, and no wide sea-margins 

 in which the sediments of the stratified rocks could 

 have been deposited. More than four fifths of the 

 continent is of secondary origin and shows that vast 

 geologic eras went to the making of it. 



It is equally hard to believe that the primary or 

 igneous rocks, where they did appear, were sufla- 

 ciently elevated to have furnished through erosion 

 the all but incalculable amount of material that 

 went to the making of our vast land areas. But 



100 



