RELATIONS OF THE ^SASKATCHEWAN^ GRAVEL 559 



30 feet of coarse "quartzite gravel" lie on the eroded surface of the Cre- 

 taceous rocks and are overlain by 10 to 12 feet of till containing occa- 

 sional Laurentian crystalline pebbles and itself overlain by a 5-foot bed 

 of gravel containing Laurentian pebbles. The only evidence of mountain 

 glaciation noted this far north in this valley was several 3-foot blocks of 

 reddish argillite in a ravine between the last two points noted. 18 



Continuing southwestward upstream, another exposure shows 10 feet 

 of "quartzite gravel" lying on the eroded surface of the Cretaceous sand- 

 stone and overlain by till containing Laurentian pebbles, and above this 

 laminated, sandy clay containing a few pebbles from the Eocky Moun- 

 tains and Laurentian crystallines. 



At the boundary line the following section was observed : 



Deposits on Saint Mary River at 49th Parallel north Latitude. 



C. Gray clayey till of Keewatin Glacier, pebbles mostly from tbe Feet 



Rocky Mountains, but with a small percentage of Laurentian 

 crystallines (Wisconsin stage) 20± 



B. Gray till, pebbles so far as noted all from the Rocky Mountains 



(mountain drift, Wisconsin stage) 20± 



A. "Quartzite gravels" ("Saskatchewan," interglacial or preglacial) 



pebbles exclusively from the Rocky Mountains, well rounded, 



ranging in size from fine to iy 2 feet in diameter 12 to 15 



Cretaceous rock. 



This is the most southerly point at which the writers have observed the 

 "quartzite gravel" underlying either the drift of the Keewatin ice-sheet 

 or the drift of Saint Mary Glacier. 



At a point on upper Belly Eiver and about 27 miles south of Macleod, 

 in township 5 north, range 26 west, a fine exposure of the "quartzite 

 gravel" was seen (plate 16). 



Deposits on Belly River 21 Miles South of Macleod, Alberta 



Feet 



D. Dark soil 1 to 2 



C. Laminated gray silt 8 to 10 



B. Solid, buff ot gray, clayey till of the Keewatin Ice- sheet, pebbles 



mostly from the Rocky Mountains, pebbles of Laurentian crys- 

 tallites scattered throughout 10 to 12 



18 At this intermediate point there is 15 to 20 feet of till, containing Laurentian peb- 

 bles overlying the eroded surface of the folded Tertiary (?) beds, and on the upturned 

 edge of one of the harder beds glacial stria 1 wore observed trending south B5" to 80' 

 west. So also at the bend, nearly oast of Sloans Ranch, at a point where overlain only 



by drift of Keewatin Ice-sheet, the upturned edge ot an oyster-bed was glacially smoothed 



and showed faint stria- trending south 80" to 50 s west. These are the only points in 



the region traversed where we found glacial stria* on the Cretaceous or Tertiary rocks 

 of the plains. 



