280 METAMORPHIC LIMESTONE 



Mont Royal rising behind with a faint resemblance to 

 Arthur's Seat, sent the heart home to more familiar 

 scenes, and almost secured beforehand for the stranger- 

 city an interest in its affections. 



In descending the St Lawrence from Kingston, the 

 somewhat naked and rocky limestone country of that 

 part of Upper Canada continues, till we have passed the 

 Thousand Isles. Below this the banks are less rocky, 

 and most of the way down to Montreal consist of a 

 light-coloured drift, which yields in general, I should 

 think, only an indifferent soil. This drift rests upon, 

 and is probably in great part formed from, the Potsdam 

 sandstone and calciferous sand-rock of the New York 

 geologists — being the lowest portions of the Lower 

 Silurian rocks. These rocks, where they occur in other 

 parts of North America, produce In general Inferior soils. 



The most interesting geological fact, bearing upon the 

 practice of agriculture, which fell under my observation 

 in this part of my tour. Is the occurrence over a large 

 part of Canada of a deposit of metamorphic limestone, 

 which is unusually rich in phosphate of lime. This 

 limestone is subordinate to, and Interstratlfied with, beds 

 of porphyrltic and syenitic gneiss, which form a long 

 ridge of high-land, dipping beneath not only all the 

 Silurian strata, but also under the copper-bearing beds 

 of Lake Superior, which are beneath the Silurian. Both 

 the limestone and the gneiss are probably highly altered 

 members of the older Cambrian series. 



This ridge of altered rocks extends, as a prolonged 

 high-land, in a north-east and south-west direction, from 

 the west of Labrador to the Ottowa, running nearly 

 parallel to the St Lawrence, and at a distance north of 

 that river of from twelve to twenty miles. Near 

 Bytown on the Ottowa the limestone appears in great 

 force, and from that point the ridge of mixed rocks 

 ranges nearly due west to the shores of Lake Huron. 



