354 



bentonite in the subsoil is probably in part the cause of the 

 waxy nature of the "gumbo" soil, and is also responsible 

 for a great many of the engineering problems, where 

 difficulty is experienced in holding a road bed on the side 

 of a cut, or even in maintaining the grade over a level 

 prairie underlain by it. 



Throughout this part of this formation there is a distinct 

 lack of continuity in the beds. In some exposures there 

 may be shown a regular succession of beds of clay with 

 no sandstone apparent, while a short distance away 

 distinct hard beds of consolidated sandstone are found 

 interbedded with shale and clay. In some cases, the clay 

 passes imperceptibly into the sandstone, and in other cases 

 gradually pinches out into a thin lens, while above it the 

 sandstone comes in again in the same manner. 



On this account it is difficult to give a section which is 

 applicable without modification throughout the whole 

 region, but the following section as worked out by J. B. 

 Tyrrell may be considered as fairly characteristic of the 

 Edmonton formation in this region. [3]. 



ft. in. 

 3-0 m. Light coloured boulder clay, including many 



Laurentian boulders and pebbles — at least io 



6-0 m. Whitish, clayey sandstone 20 



3-6 m. Grey, carbonaceous shale 12 



• 7 m. Coal (burnt out) 2 4 



4-5 m. Whitish, clayey sandstone 15 



•7 m. Coal (brown lignite) 2 3 



7-5 m. Light grey sandy shale with 6" band of iron- 

 stone near top 25 



1-8 m. Yellow, sandy shale 6 



0-6 m. Shale, mixed with coal 2 



18 -o m. Grey, readily weathering sandstone, with ir- 

 regular masses of ironstone and reptilian 



bones 60 



1-5 m. Lighter grey sandstone 5 



0-3 m. Sandstone and ironstone I 



7-5 m. Light grey, rather hard, sandy shale, with 



irregular bands of ironstone 25 



•15 m. Nodules of flinty ironstone, with impressions 



of plants o 6 



3-0 m. Light sandy shale 10 o 



0-75 m. Hard ferruginous sandstone, containing 



obscure plant impressions 2 6 



1-8 m. Light grey sandy shale 6 o 



•3 m. Rather hard lamellar sandstone 1 o 



33 o m. Light grey shaly sandstone, containing especi- 

 ally in the lower portion, more or less 

 irregular bands of ironstone nodules no o 



94-68 metres. 315 7 



