CANADA. 339 



" Among the boulders on Lake Nipissing, many were observed to be of a 

 slate conglomerate, and tbey were lieiiuently ul' very great size ; iii their as- 

 pect and general character these have a very strong resemblance to the shite 

 conglomerate of the Hiironian series, from which in all jirobability, they are 

 derived." 



The next mention is in the Report for 1855, dated March 1, 185G, 

 p. 134: — 



" The pebbles and boulders of metamorphic rocks which abound in the 

 gravel and clay deposits, and are numerously scattered over the surface, are 

 clearly derived from the I/aurentian and Iluroniau formations on the north 

 shore of Lake Huron." 



In the Report for 1856 (March 1, 1857, pp. 1G8, 172) it is stated : — 



" The rocks of the region explored during the season, embrace two of the 



oldest recognized geological formatios, the Laurentian and Huronian 



Tlie difference in lithological character between the two formations was always 

 sufficiently apparent, but though both were frequently found at short distances 

 apart, the immediate point of contact was always obscure ; and a mass of green- 

 stone of rather coarse grain was usually the fii-st intimation of the proximity 

 of the higher rocks "Whether this greenstone is the result of an over- 

 flow contemporaneous with the upper formation, or an eruptive mass intruded 

 at a later period, has not yet been ascertained." 



Regarding the hypersthene rock which has since been set apart as the 

 Upper Laurentian or Noriau Series, Dr. Hunt iu his Report for 1854: 

 (April 1, 1855, p. 374) states : — 



" The rocks about to be described belong to the crystalline strata of the 

 Laurentide mountains, and occur, as far as yet observed, in close association 

 with the crystalline limestones, which alternate with the gneissoid and quart- 

 zose rocks of the formation." 



In Dr. Hunt's Report for 1856 (April 1, 1857, p. 451, see also Philo- 

 sophical Magazine, 1855, (4 ) IX. 354, 355), it is written concerning 

 the same rocks : — 



" In the Report for 1854 I have described at some length a class of stratified 

 felspathic rocks, which form an important part of the Lnurentian series, and 

 are associated with the calcareous and maguesian deposits of that ancient 

 formation." 



The Reports here refeiTcd to from 1853 to 1856 were not published 

 until 1857. 



The division of the Azoic rocks into Laiirentian and Huronian, and 

 Logan's view that the copper-bearing rocks of Lake Superior were of 



