lllll J. B. TYRRELL — POST-TERTIARY DEPOSITS OF MANITOBA. 



steep-sided drift-built bills," the " ridge extending northwesi from Pinto- 

 horse butte" ar the bead of the middle branch of Old Wives creek and 



in approximate hit. !'.• IV N., long. 107° 45' W.) in a general direction 

 parallel to the Coteau and about fifty miles southwesl from it, ami the "spur 

 south of tin- west end of the Cypress hills " a hundred mile-, still farther 

 west. 



West <>f this ridge ami south of hit. 51 N. no terminal moraines have 

 been recognized, except such a- have been formed by glaciers flowing from 

 th<' valleys in the mountains, thro- heinu; characterized by the angularity of 

 the included pieces of rock and the absence of eastern erratics. North of 

 hit. -*>1 N'. tin- re a iv a number of ridges of distinctly morainic character. 

 ( me of the most typical of these surrounds the southern and eastern sides of 

 the Sand hills. These Latter hills form a high table-land rising twelve hun- 

 dred feet above the surrounding plains, and are surmounted by two hundred 

 and seventy feet of sands, silts, and gravel of Miocene age. Towards the 

 northwest, west, and southwest they rise in an abrupt escarpment five hun- 

 dred feet to their summit ; towards the east and southeast they decline grad- 

 ually and regularly for a short distance, aud then the slope is covered with 

 a ridge of roundel knob-like hills separated by deep kettle holes, in the bot- 

 toms of which often nestle small isolated lakes. Their summits are thickly 

 overstrewn with bowlders. 



From lift v to sixty miles further north, near the southerly bend of the 

 Lied Deer river, another similar ridge is met with, the knolls rising in many 

 places to i e than two hundred feet above the bottoms of the depressions. 



Turning directly eastward a rough, irregular tract, known as the Neutral 

 hills, is seen, the higher points of which arc thickly covered with gneissic 



and limestone erratic-, lying on a base of unmodified morainic material. 



The hills themselves lie on an elevated plateau of Cretaceous shale, which 

 has been very irregularly eroded, ao that it is often difficult to say without 

 Sections whether an individual hill is a product of denudation or is one of 

 the irregularil ies of the moraine. 



North of the Battle river the Blackfoot hills form another area of deep, 

 uuconnected depressions and high, rounded knolls, sprinkled over with 

 h iwlders of eastern gneiss. 



Other morainic belts doubtless occur in this area south of the North-Sas- 

 katchewan river, hut as yet they have not I a traced out. Enough has 



I, en done, however, to -low the former existence of a great -lacier, or " mer 

 de glace," which spread over the plain- from a source or Bources of supply 

 .,n or north of the Archean rock- to the east, and which flowed in a southerly 

 and southwesterly direction almost to the foot of the Rocky Mountains, 

 from whose valleys numerous small glaciers flowed eastward to join the 

 mighty advancing ice-sheet, leaving intervening ana- along the lorn of the 

 mountains, and roughly west of the 3,000 foot contour Line, unglaciated. 



