102 J. B. TYERELL ON THREE 



Turning now to the consideration of the fossils found in the drillings, the fragments 

 of crinoids and the Fterinea ? are of but little service in the determination of the horizon 

 of the beds. The Coleolus ? is very like a form that is common in the Stringocephalus 

 zone at A-arious exposures on the shores of Lakes Manitoba and Winnipegosis, and would 

 thus indicate to some extent a Devonian horizon. The fragments of Chonetes are too 

 imperfect to allow of the specific identification of the species, but as in several specimens 

 the hingii-liue is preserved they leave no doubt as to the genus. This genus in America 

 ranges from the Clinton, or base of the Niagara, to the Carboniferous, but is most common 

 iu the Devonian. In Manitoba two species are locally abundant in the shales and argil- 

 laceous limestones of this latter system, while none have been found in the Silurian. 

 This also points strongly to the Devonian age of the red and grey shales at Mordeu, 

 and makes it quite certain that they are not older than the Niagara. As far as is known, 

 however, the Niagara formation consists entirely of light grey limestones and dolomites, 

 without any sign of red or grey shales, and unless the character of the rock changes 

 very greatly as it is followed from north to south, the shales penetrated in the Morden well 

 would not belong to this formation. 



It remains therefore to consider the Devonian affinities of the beds in question. 

 From the well at Rosenfeld, twenty-four miles east of Morden, Dr Dawson has recorded a 

 thickness of 352 feet of red and grey shales, etc , at the top of the Palgeozoic section, but 

 from these drillings no determinable fossils were obtained. Below these shales no dolo- 

 mites were met with, and no rocks that could be supposed to represent the Middle 

 Devonian dolomites. The shales from the Morden well appear to represent a portion of 

 this Rosenfeld series, and the absence of the Stringocephalus zone seems to indicate that 

 these beds represent a lower horizon. The inference is therefore very strong that they lie 

 below the Stringocephalus zone, and represent the basal shales of the Devonian, which 

 have been eroded away and have left no salient exposures in the lacustral area to the 

 north. It has been seen, too, that in the lacustral area the strike of the contact of the 

 Devonian and Silurian runs in a fairly straight line N. 25° W., and this line being extended 

 from the southeast angle of Lake Manitoba, would cross the international boundary line a 

 few miles west of the Red river. A south-westerly dip from this line at a hypothetical ele- 

 vation of 810 feet, the elevation of Lake Manitoba, at the rate of 10 feet to the mile, proba- 

 bly abou.t the true dip of the beds here, will bring the top of the Silurian COO feet above 

 the sea at Morden, or 75 feet below the present bottom of the well. 



Boring on Vermilion River. 



■'V- 



This boring was sunk by the Manitoba Oil Company on the west bank of the Ver 

 milion River, a short distance below the crossing of the Strathclair and Lake Dauphin 

 trail, in township 23, range 20, west of the principal meridian. 



In the spring of ISSt a percussion drill was hauled north from Strathclair station, on 

 the Manitoba and Northwestern Railway, and the well was drilled to a depth of 292 feet, 

 when an accident hai>pened to the machinery which d(>layed the work for a time. 



In the following year the drill was moved a short distance farther down the valley, 

 work was resumed, and a final depth of "748 feet was reached. 



From a comparison of the sections, the second well is foiind to have been begun nine 

 feet lower, geologically, than the first, and therefore the levels of all the specimens 



