[ELIS I THE ARCH.EAN OF EASTERN CANADA l£l 



as they approach the masses of igneous rocks, generally become white or 

 cream-coloured, and present the usual aspect of the Grenville crystalline 

 limestones. It would appear, therefore, from the most recent evidence in 

 the tield and under the microscope, that the Grenville and Hastings series 

 are portions of one and the same formation with certain points of diflter- 

 ence, due chiefly to local causes. 



The crystalline rocks of the mountain ranges in eastern Quebec do 

 not present the usual features found in the rocks of the area north of the 

 Ottawa just described. They are largely schistose, micaceous, chloritic 

 and felspathic, with areas of highly crystalline limestone and schistose 

 black slates. The rocks of the series occur in an anticlinal structure and 

 are flanked throughout a great portion of their extension by strata of 

 Cambrian age. They are thus presumably Pre-Cambrian, and in their 

 general character they resemble the schistose portion of the Hastings- 

 series of the areas west of the Ottawa rather than any of the divisions 

 of the lower Laurentian. They have usually been considered as more 

 closely related to the Huronian system than to the Laurentian, and they 

 present many features common to the Pre-Cambrian rocks of southern 

 New Brunswick. 



The rocks of the Shick-Shock area are also largely schistose, with 

 epidotic. chloritic, hornblendic and serpentinous masses. They presum- 

 ably represent the same horizon as those of the Sutton mountain anti- 

 clinal to the southwest. The characteristic gneiss of the Ottawa dis- 

 trict does not anywhere appear in this area, so that these rocks may, in 

 default of better evidence, be considered as intermediate between these 

 and the lowest Cambrian. 



In northern New Brunswick the Pre-Cambrian rocks are largely 

 felsitic. In ])laces they assume a gneissic structure, but the Ottawa 

 gneiss does not appear, though there^are large areas of granite and 

 syenite. The crystalline limestones are also apparently absent from this 

 ai'ea. On the south side the}' are overlapped by black slates and sand- 

 stones, which resemble in some respects the Cambrian rocks of Nova 

 Scotia as well as certain of the Sillery strata of eastern Quebec, though 

 in the absence of fossils their exact horizon has not been ascertained. 



In the Archfean areas of southern New Brunswick the rocks present 

 more of the characters seen in the Grenville and Hastings series of On- 

 tario and Quebec. They have been divided into two principal })ortionSj 

 viz., the Laurentian and the Huronian. To the former has been assigned 

 a considerable thickness of gneiss and syenite, the colour of the rock in 

 places ass\iming a greenish tinge, as if from the presence of chlorite or 

 talc. These rocks do not exactly resemble the reddish and reddish-gray 

 Fundamental Gneiss of the Ottawa district, but as they are evidently the 

 lowest known series in this province, they may presumably be regarded 

 as their equivalents in point of age. They are succeeded by an upper 



