THE ARCHEAN ROCKS. 79 



morphism of vegetable matter such as forms coal, 

 -ting COal-fi \\ , in the formation of an- 



thracite, what appe be a transitional step 



between coal and graphite, for the percentage ot 



.-eons constitu- 

 tor the distilling action oi 

 and Ik 



If tl tphite at 



organic origin, they would appear to have been 

 original ami limestone which con- 



v, if not entirely,"!' fossils. Tin 



nstituents of these rocks, the 

 which form the | aass ^>i the country 



5l i . would appear once 



hav< 5 in which fossils mav 



hav( distribul in more recent 



the Laurentian and 

 g I [uronian n >cks - iboul 50,000 f< 

 thicknes 1 md, unless the 



which has b( 

 irentian limestones is correctly 



-building foramini- 



: winch le of occurrence in the rocks 



male structure 



alleled in volcai 5. Such metamorphism 



be must be 

 trred to have obliterated ail records of the 



y 1 >f the earth. 

 The ge Story commences at a com- 



parative mpared with the unre- 



which h ie before. Without 



such an obliteration of a past record of aim 

 infinite duration as compared with known geo- 

 logical time, it is inconceivable that processes of 

 variation, such as are now known to be in opera- 



