THE MANITOBA ESCARPMENT. 83 



found in the Belly Rivei* series and at the base and top of the Fort Pierre 

 formation. "The Belly River series," Daws6n writes, "appears to corre- 

 spond precise!}' to that occupying a similar stratig-raphical position on the 

 Peace River, and there designated the Dunvegan series. These indicate 

 the existence of a prolonged interval in the western Cretaceous area during 

 which the sea was more or less excluded from the region, and its place 

 occupied for long periods by lagoons or fresh -water lakes." ^ 



Along the Manitoha escarpment. — The Cretaceous series forming the 

 Manitoba escarpment and underlying its base has been recently studied 

 and described by ]\Ir. J. B. Tyrrell, of the Canadian Geological Survey." 

 He divides the Fort Pierre formation into two parts, naming the upper part, 

 about 500 feet in thickness, the Odanali series. This division "consists 

 almost entirely of greenish-gray clay shale, which, when wet and in place, is 

 soft enough to be easily cut with a knife, but on drying becomes quite hard 

 and brittle. It occupies all the top of the Pembina and Riding mountains, 

 but farther north no exposures of this series were seen, the country 

 throughout being very thickly covered with di-ift. No fossils of any kind 

 were found in this terrane." 



The lower part of the Fort Pierre shales, named the Millwood series, 

 also mainly about 500 feet thick, and attaining a maximum of GG-t feet in 

 the well bored at Deloraine, "consists of soft, dark-gray clay shales, with 

 nodules of ironstone in which many species of typical Pierre fossils have 

 been found. The terrane is well exposed at Millwood, 1 8 miles above Fort 

 Ellice, on the Assiniboine River, and it may also be seen in the gorges cut 

 by the Ochre and "Wilson rivers on the northeastern face of the Riding 

 Mountain, in the gorge of North Pine River in the Duck Mountain, and 

 * * * on the eastern face of Porcupine Mountain." 



The Niobrara formation, as recognized by Tyn-ell in borings on the 

 Vermillion River at the northeastern base of the Riding Mountain escarp- 



' Geol. aud Nat. Hist. Survey of Canada, Report of Progress for 1882-83-84 ; and Descriptive 

 Sketch of the Physical Geography and Geology of Canada, 1884. 



Sir William Dawson, Whitoaves, aud Cope find the fossils of the Belly River series "identical 

 •with those of the Laramie." Am. Naturalist, Vol. XXI, p. 171, February, 1887, 



= " The Cretaceous of JIanitoha," Am. .lour. Sci. (3), Vol. XL, pp. 227-232, September, 1890; and 

 "Foramiuifera and Radiolaria from the Cretaceous of Manitoba," Trans. Roy. Soc. Canada, Vol. VIII, 

 sec. 4, 1890, pp. 111-11.5. 



