[ami] SYNOPSIS OF THE GEOLOGY OF CANADA 215 
from Exmouth island, obtained by Sir E. Belcher ascribed by Sir Richard 
Owen to Zchthyosaurus. 
In the interior Continental plateau overlying the Trias of the Peace 
and Pine river country, certain shales and sandstones may possibly be 
referred to the Jurassic system. The continent of America and that 
portion with which this chapter deals was probably elevated to a great 
extent above the sea level, and erosion rather than deposition was going 
on in those days. 
‘HE CRETACEOUS SYSTEM. 
The Acadian Region.—Overlying the eruptive traps of the North 
mountain in Annapolis county, near Ira Woodworth’s bay, below Scot’s 
bay, and on the east side of the bay of Fundy, there occur a series of 
light yellowish gray and green impure limestones and shales, which Dr. 
Ells has recently discussed in an interesting paper in which he argues 
the possible existence of strata referable to the Cretaceous system. No 
trace of organic remains has as yet been detected in these limestones. 
Obscure concretions are said to occur in them, but no definite fauna has 
yet been examined. These strata lie unconformably over the latest erup- 
tives of the region and constitute a well-defined horizon in which subse- 
quent researches may afford paleontological data to enable us to correlate 
the strata in question. 
In the Laurentian Highlands, and throughout the Lawrencian 
Lowlands no rocks of Cretaceous age have as ‘yet been detected either 
in situ or in Pleistocene drift. ‘These portions of Canada must have 
been above the level of the sea during Mesozoic and Tertiary times. 
The Interior Continental Plain.—In Manitoba and vicinity along the 
Red Deer river, north of Pine river, along the Vermillion and Assiniboine, 
and at Shoal lake, as well as at Deloraine, the Cretaceous system is 
represented by the following series of formations in ascending order: 
1, The Dakota formation, consisting of light and dark brown, at times 
friable compact or shaly sandstones, especially on the Red Deer and 
Rolling rivers, in Saskatchewan. 2, The Benton formation, consisting 
for the most part of dark-bluish, gray or black shales, sometimes car- 
bonaceous, at others holding glauconite in the form of foraminiferal 
casts, as seen in the drillings from the Deloraine well, from a depth of 
1820 feet. 3, The Niobrara formation, which consists of dark gray or 
brown and bluish more or less fissile and phosphatic fossiliferous shales, 
characterized by the presence of Inoceramus problematicus, Schlotheim, 
interstratified with more or less dolomitic limestones. This formation 
is well developed on the Vermillion river. 4, The Pierre formation, 
