

I^ILIBRARYIr 



v^W.., 



THE OTTAWA f(ATURALIST. 



Vol. XV. OTTAWA, AUGUST, 1901. No. 5. 



THE PHYSICAL GEOGRAPHY OF THE RED RIVER 



VALLEY. 



By D. B. DowLiNG, B. Sc. 



A critical study of the physical features of any region is not 

 complete nor is its full sig'nificance understood if there is not added 

 some note referring- to the great changes which have contributed 

 to its history. Many of the bolder features such as mountain 

 ranges show in the bending and folding of the beds composing 

 their mass, a yielding to great lateral pressure and consequent 

 upheaval. Similarly all the surface deformations offer evidence as 

 being the result of various agencies ; whether changes in elevation, 

 folding and breaking of the crust or the continued action of atmos- 

 pheric or climatic conditions. 



In the district to be discussed the principal movements 

 recorded are changes in elevation during which the sea advanced 

 or retired and was the principal agent in the deformation and sub- 

 sequent addition to the deposits on the earth's crust. 



A reference to the illustration will show the general nature 

 of the valley from the height-of-land at Lake Traverse northward 

 to the Manitoba lakes. It broadens toward the north and in 

 Manitoba is seen to include a wide tract — ^the first prairie steppe — 

 extending from the hills bordering it on the west, to the rougher 

 country lying to the east of Lake Winnipeg. 



The general character of the country on both borders is quite 

 distinct and the plain, through which the river runs, forms an area 

 of a still different type. The character of each is primarily caused 

 by the relative hardness and formation of the material forming the 

 crust of the earth beneath. 



.c^ 



