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CANADA. 



339 



" Among tlie Louklcrs ou Lake Nipissing, many were o'bsGrvei.l to "be of a 

 elate conglomerate, and they were fretj^uelitly of very great size ; in their as- 

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

 conglomerate of the ITuronian series, from which in all probability, they are 

 derived." 



The next mention is in tlio Ecport for 1855, dated March 1, 1856, 

 p. 134 : 



" The pebbles and bonlders of metamorpliic rocks which abound in the 

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

 clearly derived from the Laurehtian and Iluronian formations on the north 



shore of Lake Huron." 



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



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

 oldest recognized geological formatios, the Laurentian and Huronian. .... 

 The difference in lithoh)gical character between the two formations was always 

 SuITiciently apparent, but thougli both were frequently found at short distances 

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

 stone of rather coarse grain was usually the fu-st intimation pf 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." 



Eegarding the hypersthene rock which lias since been set apart as the 

 tipper Laurentian or Norian Series, Dr. Hunt in his Ileport 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 gncissoid and ouart- 

 zosc rocks of the formation." 



In Dr. Hunt's Report for 1§56 (April 1, 1857, p. 451, see also Philo- 

 Bophical 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 

 felspatliic rocks, which form an important part of tlie Laurentian series, and 

 are associated with the calcareous and magnesian deposits of that ancient 

 formation." 



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

 until 1857. 



The division of the Azoic rocks into Laurentian and Iluronian, and 

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



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