i68 The Ottawa Naturalist. 



Rivers ; but at this place they are overlaid by horizontal beds of 

 the Calcifcrous limestone which show at several points in the 

 town and along the river up to Braeside to the south of which, 

 however, the fossiliferous ledges of the Black River formation 

 are seen and arc well worthy of study, several quarries being 

 located in its .strata. A little farther west, to the south of 

 Sand Toint, excellent opportunities are also presented for collect- 

 ing the characteristic fossils of the formation, the beds holding 

 Tetradiiau fibratum being well developed about a mile south of 

 the last named place. 



The bluish-striped lirnestones of Arnprior, and of the 

 section thence to Renfrew, belong to what has been called the 

 Hastings Series ; and by crossing the Ottawa River by the ferry 

 from Braeside, their continuation into the province of Quebec 

 can be readily seen, the association of striped crystalline lime- 

 stone, hornblende rocks and dolomitic and other schists being 

 well exhibited, so that this locality is a very interesting one 

 from the geological standpoint. The celebrated Iron mines of 

 Bristol are situated in the rocks of this series on the Quebec 

 side of the Ottawa. 



Between Arnprior and Glasgow, the next station, the road 

 traverses an area, largely clay covered, but ridges of the peculiar 

 bluish-striped crystalline limestone, which is extensively quarried 

 at Arnprior, occur at intervals. At Glasgow, however, these are 

 cut off by a well pronounced area of reddish granite which 

 crosses the track and extends northward for several miles. In 

 its westwaid extension this granitic belt has a breadth of 

 several m.iles on the Renfrew and Burnstown road and is an im- 

 portant geological feature in this area. From Glasgow to 

 Renfrew, the rocks, where exposed, are alternately granites and 

 crystalline limestone, the latter predominating as Renfrew is 

 approached. At this latter place extensive quarries are in 

 operation in the limestone and large quantities are extracted, 

 both for building and for burning to lime, for both of which pur- 

 poses it is well suited. 



West of Renfrew an extensive clay flat extends up the 



