67 



Miles and Keewatin again outcrops, and with intrusions 

 i ome res. q £ ^g gabbro continues to milepost 222. The 

 gabbro-Coutchiching contact is followed some- 

 what closely to mile-post 224, where, near 

 the westerly end of the Rainy Lake crossing, 

 the railway passes into the Algoman granite. 



After leaving the lake, the alluvial plain 



country is entered and only occasional outcrops 



are visible. The eastern boundary of the bed 



of glacial Lake Agassiz (12) has not been very 



accurately located, but it is believed to be near 



the eastern edge of Rainy lake. The lake 



deposits may be seen almost continuously 



to Winnipeg, although the sands and stratified 



gravels have been rearranged in places to form 



part of the alluvial plain of Rainy river. 



231-3 m. Fort Frances. — Altitude 113 ft. (340 m.). 



372-3 km. The bed-rock from Fort Frances westward to 



Winnipeg is almost unexposed. From the 



occasional outcrops that do occur, and from 



the small mining operations carried on in the 



region, it is believed that the country is under- 



286 m. lain (Rainy river) chiefly by rocks of Pre-Cam- 



460 km. brian age, at least as far west as the Manitoba 



boundary The description by Dr. Lawson (6) of 



an exposure of possibly Richmond fossiliferous 



limestone (Ordovician) about six miles (9-6 km.) 



west of Fort Frances is interesting, as it may 



prove to be an outlier of the Palaeozoic of 



Manitoba. 



324 m. Warroad. — At Beaudette the railway crosses 



521 -4 km. the International Boundary line into United 



States territory, through which it runs for about 



35 miles (56 km.), crossing back into Canada 



a few miles beyond Warroad. 



439 m. Winnipeg. — Altitude 760 ft. (231*6 m.). 



706 km. 



BIBLIOGRAPHY. 



1. Coleman, A. P Gold in Ontario; its associated 



Rocks and Minerals. 4th. Rep. 

 Bur. Mines, Ontario, 1894, pp. 

 35-100. 

 35069— 5| 



