43 



The railway runs for two miles (3.2 km.) through a 

 nearly flat plain formed of the dark grey, easily weathered 

 norite, cut in one or two places by later granite. The 

 norite then merges into reddish grey micropegmatite rising 

 as rugged hills. 



At Azilda, alt. 891 (271.8 m.), 7 miles (11.3 km.) from 

 Sudbury, the railway enters the interior plain of the nickel 

 basin, having come in by the easiest pass through the acid 

 edge of the nickel eruptive. This plain of farmlands is 

 formed of silt deposited in a bay of lake Algonquin, and 

 Whitewater lake, a mile to the south, lies at the boundary 

 of the interior sedimentary rocks against the eruptives. All 

 round the basin, which is 35 miles (56.3 km.) long and 10 

 (16.1 km.) wide, may be seen hills of micropegmatite and of 

 conglomerate which it has metamorphosed. 



At Chelmsford, alt. 888 feet (270.6 m.), 12 miles 

 (19.3 km.) northwest of Sudbury, in the middle of the 

 basin, low anticlinal domes of sandstone begin, one of the 

 largest lying southeast of the village. 



At Larchwood, alt. 885 feet (269.7 m.), 18 miles (29 

 km.) from Sudbury the railway cuts through one end of a 

 ruined dome just east of the Vermilion river, which crosses 

 the upturned edges of sandstone as pretty rapids. 



At Phelans, alt. 937 (285.6 m.), 21 miles (33.8 km.) 

 from Sudbury, the railway ascends a gravel terrace, a 

 delta deposit of the river where it entered lake Algonquin, 

 and not far beyond is the beautiful falls of Onaping river, 

 more than 100 feet (30.4 m.) in total height, over Onaping 

 tuff, the third member of the Animikie as found in the 

 nickel basin. 



At Levak siding, alt. 1,020 feet (310.9 m.), 24 miles 

 (38.6 km.) from Sudbury, the railway is in the midst of 

 high and rugged hills of micropegmatite. 



Three miles beyond, near Windy lake, alt. 1,221 feet, 

 (373.7 m.), the basic edge of the nickel eruptive is found. 

 A few hundred yards of drift, including an esker ridge, 

 separate the last outcrop of norite from the Laurentian, 

 which rises as the usual hummocky hills of gneiss. 



After traversing the whole width of the nickel basin by 

 train it is intended to halt for a studv of various points of 

 interest on the way back. A walk lasting two hours and 

 covering about 3 miles will be made along the railway east- 



