Miles and 

 Kilometres. 



with soil. As the train approaches milepost 232 

 a good view is obtained of an esker-like ridge 

 laid down apparently by a southward flowing 

 englacial stream. The forest in this vicinity 

 has been fire-swept, and the sinuous course of 

 the ridge may be easily observed for nearly a 

 mile to the north. Farthest away it is a low 

 ridge of coarse boulders, but, approaching the 

 railway, it grades successively into gravel and 

 sand, becoming higher and broader at the same 

 time. Where the railway cuts through it to a 

 depth of 40 feet (12-2 m.), it consists of con- 

 vexly bedded and cross-bedded sands, through 

 which are scattered occasional large boulders. 

 South of the track it merges into the terminal 

 moraine already mentioned. The course of 

 this glacial stream was evidently independent 

 of the topography of the ice-covered country, 

 for the deposit which marks it winds up a steep 

 slope to the railway. A small kettle lake on 

 the south side of the railway can be seen from 

 the same point. 



Schists of the Keewatin-Lower Huronian 

 group are seen first near milepost 236. For 29 

 miles (46-4 km.) eastward from this point, the 

 railway runs near the northern margin of a large 

 area of these rocks, crossing at irregular inter- 

 vals tongues of Laurentian, which are intrusive 

 into it from the north. But, for most of this 

 distance, the rocks are poorly exposed. 



Intrusive dykes and tongues of granite are 

 especially common between mileposts 236 and 

 250. Ordinarily the Laurentian is strongly 

 gneissic at its contacts with the Keewatin, and 

 includes a large proportion of fragments of the 

 older formation. Less frequently the magma 

 seems to have been more fluid and crystallized 

 as massive granite, nearly free from xenoliths. 

 The contacts in this vicinity are of the latter 

 type. At -25 mile (-4 km.) east of mile- 

 post 249, for example, granite is in sharp con- 

 tact with an overarching chloritic schist. The 

 granite in this and similar cases approximates 

 more or less closely in composition to a true 



