SIE R. I. MURCHISON ON THE GNEISS OF SCOTLAND. 279 



formed the boundaries of this branch of the Great Win- 

 nipeg. 



The series composing the country east of Eainy Lake 

 towards the Height of Land are again reproduced after 

 passing the large area of intrusive granite on the Win- 

 nipeg, and continue with some considerable variations of 

 strike and dip occasioned by intrusions, as far as the first 

 falls below the Bonnet Portage, where drift clays conceal 

 the rocks on the banks of the river to its mouth, ex- 

 posures occurring only at the different falls and portages. 



The Laurentian rocks which form the whole of the 

 low east coast of Lake Winnipeg strike off at its north- 

 east corner, and passing to the north of Moose Lake, go 

 on to Beaver Lake.* 



The only exposure of Laurentian rocks seen within 

 the area explored west of Lake Winnipeg were observed 

 in St. Martin Lake ; they have been described in Chap- 

 ter XXVI. 



In the Quarterly Journal of the Geological Society for 

 August, 1860, Sir Eoderick I. Murchison made the follow- 

 ing interesting and important announcement respecting the 

 age of the Fundamental Gneiss of Scotland, and conferred 

 an appropriate acknowledgment of the services rendered 

 to geology by the distinguished director of the Survey in 

 Canada, by adopting a Canadian geological name for the 

 British rocks of the same age as those which Sir William 

 Logan has named the Laurentian System. 



" The changes which are involved in the adoption of 

 my views of the order of succession are, it will be ad- 

 mitted, considerable. In the first place, by showing that 

 mountain masses of sandstone and conglomerate lie un- 

 conformably beneath quartzose and calcareous rocks with 



* Sir John Richardson's Journal of a Boat Voyage, &c, p. 49. Am. Ed. 



