
CRETACEOUS AND TERTIARY—PEMBINA RIVER. 83 
190. The most promising bank in this locality yielded, when thus 
treated, the following section :— 

Clay-shale, rather hard............... PR a8 25a it 0 
SEEN DS is Pee ook. nda Se ces Sade teees bine Tore a 
Clay-shale, rusty and decomposed..................0.5 Rds BAG 
SENT PO MNTTEMMONMEM SS Se... ce ee nln ewete asace 30 0 
39 2 
The lower shale is so soft as to merit rather the appellatfon of hardened 
clay. It is blackish in colour, from the admixture of a small quantity of 
carbonaceous matter, and also holds minute selenite crystals and fragmen- 
tary fish remains; the latter quite comparable with those already de- 
scribed, in form and state of preservation. Above this is a bed of soft 
decomposed clay-slate, rusty in colour, and holding much selenite in small 
stellar groups, which are generally arranged in fissures and partings of 
the rock. They have been developed, no doubt, by the decomposition of 
iron pyrites in the bed, subsequent to its deposition, and under the 
influence of percolating waters. 
191. The ironstone, though nodular, forms a nearly continuous 
sheet in some places of about two inches in average thickness. It is grey 
within and rather compact, though weathering brown and becoming soft 
externally. A sample examined was found to contain but 21:78 per cent. 
of metallic iron. 
192. The upper portion of the section consists of harder clay-shale, 
which is, however, when freshly exposed and full of moisture, compara- 
tively soft, and shows little tendency to break along its deposition planes. 
When dried and weathered it becomes harder, and splits easily into rather 
thin leaves. Its colour when in the bank is sombre olive-grey, but on 
the surface a pale whitish-grey. It contains no fossils, unless certain 
branching rusty lines, or small tuhes, with which some layers are pene- 
trated in every direction, may represent fucoidal remains. 
193. The lower part of this stratum is probably sixty feet above the 
level of the Pembina River, and though not actually seen at a higher 
level in the bank at this place, it occurs at a greater elevation in other 
sections. Its crumbled remains also exist at a higher level near this 
place, and form the subsoil of the prairie wherever the surface has been 
disturbed sufficiently to bring it to view, for some distance west of the 
Pembina Valley. As the beds appear to be perfectly horizontal, this 
stratum would have a thickness, measuring upward from its base in the 
section just given, of at least 240 feet, 
