7 
Physical Features of Manitoba, with Special Reference to the 
Hudson Bay Area 
The province of Manitoba extends for a distance of 750 
miles between the forty-ninth and sixtieth parallels of latitude. 
Its greatest width is approximately 480 miles, at about the fifty- 
seventh parallel. Its total area is approximately a quarter of a 
million square miles, of which, however, only the section south 
and west of Lake Winnipeg is suitable for agriculture. Mining, 
trapping, fishing, and lumbering are important industries in the 
central and low-northern regions. 
An excellent account of the geological formations of 
Manitoba is given by Wallace (1925), who notes the occurrence 
of five main groups, namely: Precambrian granites, gneisses, 
lavas, and sediments; Ordovician, Silurian, and Devonian lime- 
stones, dolomites, sandstones, and shales; and Cretaceous 
shales. The approximate extent of the five major formations is 
shown by Wallace in his Plate VIII, p. 36. 
The southwestern boundary of the Precambrian extends from 
the southeastern corner of the province up the long axis of Lake 
Winnipeg (an erosion lake between the Precambrian and the 
overlying limestones), and turns westward to the Saskatchewan 
boundary at about the fifty-fifth parallel. The northeastern bound- 
ary follows the coast of Hudson Bay from the sixtieth parallel to 
the neighbourhood of Churchill, from where the Precambrian- 
Ordovician contact extends in a generally southward direction to 
the Nelson River near Gillam, thence southeastward to the Hayes 
River, and east to the Ontario boundary at about latitude 55° 
40 ' N. 
Relatively narrow bands of Ordovician and Silurian forma- 
tions parallel the two Precambrian boundaries, those to the 
northeast forming the Hudson Bay Lowlands, those to the south- 
west, together with an adjacent band of Devonian rocks, forming 
the Manitoba Lowlands (sometimes referred to as the “first 
prairie steppe”). To quote Wallace, “The southwestern part of 
Manitoba, north to the latitude of Dawson Bay, Lake Winnipeg- 
osis, which comprises about one-tenth of the area of the province, 
