

7 e , 
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~ localities, south of the Black Hills, inl along the base of the! k 
Mountains. In Nebraska, this division is described as ae of 
“dark grey laminated clays, with lighter coloured arenaceous part ngs, 
and layers and beds of sandstone. Towards the upper part, near its cot a4 
nection with the Niobrara Division above it, it sometimes includes inter- 
- ealated layers of grey limestone, in all respects similar to the lower 
portions of the overlying rock; while at some other places, its upper 
portion passes into a dark shale.”* Furthcr west it is very a 
developed near Fort Benton on the Missouri, from which it takes its 
name. The beds here “assume the form of black plastic laminated clay, 
with numerous calcareous concretions.” + The western edge of this 
division in Colorado, shows shaly beds, which, though generally argilla- ie: 
ceous, are occasionally quite arenaceous, and sometimes more or less si 
calcareous; the total thickness varying from 200 to 400 feet. f ae 
343. In the eastern region of British North America, this portion, a 
of the formation seems to have been pretty clearly recognized,on the 
Saskatchewan, near Fort 4 la Corne, by Prof. Hind, who says:— 
“On the North Branch of the Saskatchewan, and a few miles above the oF 

































4 Grand Forks, huge masses of a dark coloured, almost black shale, with 
p sharp well-preserved edges, jut out of the banks, and are exposed 
ge whenever portions of the face of the clay cliffs fall into the river. Their 
j appearance is such as to justify the expectation, that rock in position, 
z . from which they originated, is close at hand. Some specimens which I 
aa procured and sent to Mr. Meek, contain, according to that gentleman, 
a fish scales, sharks’ teeth and Jnoceramus, which renders it almost certain | 
Mf that the masses were detached from rocks belonging to formation 2,or 
3, of the vertical section.”§ Cretaceous No. 2 is also stated to have been en 
bs recognized from specimens found on the Assineboine River, 250 miles 
a west of Fort Garry ;|| but, as the locality thus described must be near 
Fort Ellice, where the exposures are few, and Dr. Hector, who has” ie 
examined them, found fossils characteristic of the 4th group only; it is — 
probable that some mistake has arisen, either in the localization of the 
specimens, or from their obscurity. , 
344. Dr. Hector, though he does not expressly state that he con-— 
siders his Group D., as representing the Fort Benton, or 2nd group of 
Meek and Hayden’s section, implies as much by placing it between beds 

* Geological Report Yellowstone and Missouri Expedition. t Ibid. p. 93. 
t U.S. Geol.Surv. Territ., 1873. p- 101. 
§ Report Assineboine and Saskatchewan ‘Exploring Expedition, 1859. 
|| Prof. Meek, in Geological Report Yellowstone and Missouri Expedition. p. 16. 

Fete ‘ Perit ee! 
