154 



Knomet"rls ^3 ^° ^'^ "^'^ °^ blaclc Vegetable mould over- 

 lying poorly assorted, boulder clay or yellow 

 mud. 



Red river is crossed at the outskirts of 

 Winnipeg. 

 5 -4 m. Transcona — Altitude 758 ft. (231-1 m.). The 



8-6 km. workshops and terminal yards of the Grand 

 Trunk Pacific railway are situated at Transcona. 

 31 -om. Vivian — Altitude 891-5 ft. (271 -8 m.). The 



49-6 km. monotonous flatness of the prairie is broken 

 just west of Vivian by a low, flat-topped ridge 

 through which the railway has made a cut 

 12 feet (3-9 m.) deep and 150 feet (45 m.) long. 

 The gravel and sand composing this ridge are 

 cross-bedded, and the larger pebbles have the 

 the flattened shapes of beach shingle. While 

 it has not been more carefully investigated and 

 its extent north and south of the railway is un- 

 known, this ridge is thought to be an old Lake 

 Agassiz beach. 

 56-2 m. Elma — Altitude 921 ft. (280-9 ^n.). The 



89-9 km. first outcrop of Laurentian gneiss is seen just 



west of milepost 56. 

 65 - 3 m. Hoctor — Altitude 999 ft. (304 •7m.). Between 



104-5 km. milepost 60 and Hoctor the flat alluvial lake 

 bottom gives place to the rocky Pre-Cambrian 

 region. Low masses of rock protrude more 

 and more frequently through the flat swamps 

 and muskegs, and occasional lakes, so charac- 

 teristic a feature of the Pre-Cambrian regiqn, 

 appear. The rocks exposed here and for the 

 the next 165 miles (274 km.) are all Laurentian 

 gneisses or "transition zone" mixtures of 

 Laurentian gneiss and Keewatin inclusions. 



The Canadian Pacific railway is crossed at 

 -65 miles (i-o km.) east of milepost 69. 

 99-3 m. Malachi — 1,082 ft. (330- m.). Between White 



158-9 km. and Malachi, the gneiss contains a large pro- 

 portion of Keewatin inclusions ranging in 

 form from angular blocks to slender ribbons. 

 From milepost 80 to milepost 84 the proportion 

 of Keewatin material (hornblende gneiss) in- 

 creases to 75 per cent and is traversed only by 

 dykes and stringers of Laurentian granite and 



