558 



PKE-WISCOXSIX GLACIAL DRIFT IX MONTANA 



section on Belly Eiver within the terminal moraine of the Keewatin ice- 

 sheet showing in order, beginning at the bottom : 



"A Till formed by Belly River Glacier containing many boulders, all of 

 which are smoothed and striated to an unusual degree. 75 feet; B, Soil, of 

 which only a small exposure was seen, which contained no fossils; C, Till 

 formed by the Keewatin ice-sheet. SO feet." 



He did not, however, regard the soil (B) as indicating any considerable 

 lapse of time between the deposition of the mountain drift (A) and the 

 overlying drift of the Keewatin ice-sheet ( C ) . Xo such intervening bed 

 as the soil (B) was observed by the present writers in any of the expo- 

 sures where they saw mountain drift overlain by drift from the Keewatin 

 ice. 



Eelatioxs of the "Saskatchewan" Gravel 



The relations of the "quartzite gravels" which have been included under 

 the name "Saskatchewan*" will now be considered. 





Figure 8. — Section on Saint Mary River 1 Mile South of Kimball, Alberta 



A, quartzite gravel ("Saskatchewan"!, interglacial (?), to 15 feet, overlying, sand- 

 stone ; B, Wisconsin till of Keewatin glacier. 50 to 100 feet : C, loess-like clay, 10 feet ; 

 D, gravel overlain by a few feet of soil. 



We observed on Belly Eiver, in the vicinity of Lethbridge, 10 to 15 

 feet of "quartzite grave?' overlying the Cretaceous beds and underlving 

 the lower boulder-clay (figure ?. A). Forty miles farther south in Saint 

 Mary Valley, about 1 mile above Kimball (figure 8), to 15 feet of 

 similar quartzite gravel is overlain by 50 to 100 feet of till from the 

 Keewatin ice-sheet, which apparently composes a single drift sheet and 

 which we are inclined to regard as the upper boulder-clay. The bed of 

 gravel pinches out midway in the length of this exposure against the ris- 

 ing surface of the underlying upturned and eroded sandstone, as though 

 deposited only in the bottom of the preglacial valley. 



At the bend nearly opposite Sloans Ranch, a few miles farther south, 



