550 



PRE-WISCONSIN GLACIAL DRIFT IN MONTANA 



The bluff on the opposite side of the river at the bend north of the 

 wagon bridge exposed the following (figure 7) : 



Pleistocene Deposits on Belly River near Lethhridge, Alberta 



D. Loose buff till of Keewatin Glacier (Wisconsin stage), with Lau- Feet 



rentian pebbles and pebbles from Rocky Mountains 3 to 13 



fLaniinated. papery silt 1 to 3 



C. J Buff, wind-bedded loess, alternating with beds of fine, stratified 



sand (interglacial ?) to 5Q± 



Compact, jointed till of Keewatin Glacier (pre-Wisconsin stage), 

 with Laurentian pebbles and pebbles from Rocky Mountains. 



Upper 15 feet oxidized buff in places, dark gray below 25 to 30 



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



with some interbedded sand 10 to 15 



Cretaceous shale 100 



B 



6 

 A 



:0: o'.v.o •.-.°.v- ?.'-lZ--?- -.'• ".-o-'-v-rj-; . ; ••; 



Figure 7. — Section on Belly River near Lethhridge, Alberta 



A, quartzite gravels ("Saskatchewan"), interglacial or preglacial, 10 to 15 feet, over- 

 lying Cretaceous shale ; B, pre-Wisconsin till of Keewatin Glacier, 25 to 30 feet ; C, loess 

 and wind-blown sand, to 50 feet, overlain by laminated silt, 1 to 3 feet (interglacial?) ; 

 D, Wisconsin till of Keewatin Glacier, 3 to 13 feet. 



The gravel (A) in the two sections, which represents the Saskatchewan 

 gravel of Dawson and McConnell, is composed exclusively, where exam- 



