350 



MINERALS AND GEOLOGY 



The Upper Silurian strata of the Appalachian District, although 

 originally regarded as forming the principal part of the " Gaspe 

 Limestone series " of the late Sir William Logan, are but slightly 

 developed in Gasp^ proper, the supposed Upper Silurian beds of that 

 region being now shewn by their fossils to be chiefly of Devonian 

 age. But Upper Silurian strata if rightly determined occur some- 

 what largely in the south-eastern part of the district, south of the 

 central crystalline region. In the Eastern townships of Orford. 

 Melbourne, Westbury and adjacent sites, and in their extension 

 across the Chaudiere, they consist essentially of dark -gray or black 

 slates, and are seen in places to overlie the Calciferous (Quebec) 

 strata unconformably. These slates have been largely quarried for 

 rooting purposes in the township of Melbourne, and to some extent 

 also in Cleveland and adjacent townships. The Chaudiere slates in 

 the country around St. George, and elsewhere in Beauce County, 

 exactly resemble the hard black slates on the St. Lawrence opposite 

 Quebec, and shew no trace of fossils. They form the broken floor or 

 " bed-rock " on which the alluvial gold of this part of the Chaudiere 

 valley essentially rests ; and here and there they are traversed by 

 quartz veins carrying small quantities of gold. In Gaspe proper, 

 the Upper Silurian strata are composed mainly of calcareous beds, 

 consisting of grey limestones and shales ; but according to Mr. Ells. 

 to whom our recent knowledge of the geology of the Gasp^ coast is 

 chiefly due, these strata occupy a much smaller area then that 

 formerly assigned to them, most of the Gaspe limestones holding De- 

 vonian fossils. Those to which an Upper Silurian age may be attribu- 

 ted, are exposed chiefly on the Grand River of the south coast, and 

 along the shore between the Pabos River and Cape D'Espoir. At 

 these points they underlie unconformably the Lower Carboniferous 

 Bonaventure beds. 



The Devonian formations of the region now under review, besides 

 comprising the great body of the " Gaspe limestones and sandstones," 

 occur undoubtedly in the more southern of the Eastern Townships, 

 but, as a rule, in a more or less altered condition, and not clearly 

 separable from associated Silurian strata. Many of the grey, black, 

 and marbled limestones, however, of this area, as those of Weedon, 

 Duds well and Lake Memphremagog, as well as the micaceous lime- 

 stones of Compton and adjacent townships, are apparently Devonian. 



