310 Tertiary. 



south side of Echo lake S. 55° W. ; half a mile below S. 70° W. ; in a 

 depression north of Walker lake S. 17° W. ; Thessalon river above 

 Eock lake S. 25° W, ; west and south sides of Rock lake S. 15° W. ; 

 east side of bay at Bruce Mines S. ; northwest end of Wahbiqueko- 

 bingsing lake S, ; southeast end of same lake S. 12° W. 



Instances* of the abraded and polished surfaces of rock are very 

 numerous on the Canoe route from Lake Superior to Lake Winnipeg. 

 Near Baril Portage, 143 miles from Lake Superior, and 1,500 feet 

 above the sea, gneissoid hills and islands are smooth and sometimes 

 roughly polished on the northerly side, while on the southern side 

 they are precipitous and abrupt. On Sturgeon lake, 208 miles from 

 Lake Superior, and 1,156 feet above the sea, the northeastern extremi- 

 ties of hill ranges slope to the water's edge, and when bare are always 

 found to be smoothed and ground down. The aspect of the south and 

 southwestern exposures, is that of precipitous escarpments. The 

 summits of the granite hills near Lake Winnipeg are abraded and 

 frequentl}^ so smooth and polished as to make walking upon them 

 difficult, if not impossible in moderately steep places. 



On the south branch of the Saskatchewan the drift is exposed in 

 cliffs 50 to 80 feet in altitude at the bends of the river. The drift con- 

 sists of cla}^ with long lines of bowlders in it at different elevations. 

 Some of the fragments of shale, slabs of limestone and small bowlders 

 imbedded in the clay, stand in the di'ift with the longest axis vertical, 

 others slanting, and some are placed as it were upon their edges. Long 

 lines of bowlders lie horizontally from ten to twenty feet below the 

 surface or top of the cliff, while below, in many places, close to the 

 water's edge, and rising from it in a slope for a space of 25 to 30 feet, 

 the bowlders are packed like stones in an artificial pavement, and 

 often ground down to a uniform level hy the action of ice, exhibiting 

 ice grooves and scratches in the direction of the current. This pave- 

 ment is shown for many miles in aggregate length at the bends of the 

 river. Sometimes it resembles fine mosaic work, at other times it is 

 rugged, where granite bowlders have long resisted the wear of the ice, 

 and protected those of softer materials lying less exposed. 



Two tiers of bowlders, separated by an interval of 20 feet, are often 

 seen in the clay cliffs. The lower tier contains very large fragments of 

 water-worn limestone, granite and gneissoid bowlders, above them 

 is a hard sand containing pebbles; this is followed by an extremely 

 fine stratified claj', breaking up into excessively thin laj'ers, which 



* Assiniboine and Saskatchewan Expl. Exped. 



