412. W. UPHAM ESKER NEAR WINNIPEG^ MANITOBA 



general level, to the south edge of the top of the esker, which was some- 

 what flat and platean-like for the width of 300 to 800 feet, while its 

 southern and northern slopes add some 700 feet, making the whole width 

 of the esker 1,000 to 1,500 feet, here having its most massive develop- 

 ment. 



The west half of this excavation consists of sand and gravel, mostly 

 not very coarse, the pebbles in the coarser beds being from 4 to 6 inches 

 in diameter, excavated to the depth of 10 to 20 or 25 feet, continuing still 

 deeper on the north, but along the south line of the section seen to rest 

 on till. In its east half the excavation is gravel and sand from 6 to 20 

 or 30 feet deep, underlain by till, which rises to a height of 30 to 40 feet 

 or more above the general level, so that if the overlying esker deposit 

 were wholly removed a broad ridge of till would be exposed. 



About 800 to 1,100 feet west from the east line of this section 34, the 

 north and lower side of the excavation showed a cut in the till 18 to 20 

 feet thick and 15 rods or more in length, also extending deeper. It is 

 entirely free from evidences of water action, and contains frequent boul- 

 ders 1 to 2 feet in diameter throughout its mass, not more plentiful at 

 or near its top than below. Its whole thickness thus exposed is oxidized, 

 having nearly the same yellowish gray color as the gravel and sand. The 

 lack of larger boulders and their occurrence in no greater numbers at 

 the top of the till deposit indicate that it was formed beneath moving 

 ice, though probably thus amassed englacially, rather than by accumula- 

 tion from superglacial drift, like many hillocks and ridges of marginal 

 and interlobate moraines, which commonly are characterized by the abun- 

 dance of boulders in and upon them. Coinciding in position with the 

 broadest part of the esker, this exceptional mound or wide ridge of under- 

 lying till, rising high above the general level of the country, is almost 

 surely attributable to conditions that produced both the prominent mass 

 of till and the esker, in or beneath which it is a nucleal deposit. 



On the north side of the west part of this Canadian N'orthern Eailway 

 excavation, the northern slope of the esker has been excavated along a 

 distance of about a quarter of a mile by the Eli Sand Compan}^, which 

 also has large sand and gravel pits near Eli Station, some 30 miles west- 

 northwest of Winnipeg. This cut, 10 to 25 feet deep and 10 to 15 rods 

 wide, consists of coarse and fine gravel, with thin sand layers. The 

 stratification, nearly horizontal, or dipping in some places 5 to 10 degrees 

 east, is much broken by faults ; and the beds are quite irregular, varying 

 much in thickness within short distances, and having the coarse and finer 

 layers confusedly interbedded. Cross-bedding is frequent, with the cur- 



