The Ottawa Naturalist. 



52 LIBRAR 



& 



Vol. IX. OTTAWA, JUNE, 1895. No. 3. 



NOTES ON THE STRATIGRAPHY OF THE CAMBRO- 



SILURIAN ROCKS OF EASTERN MANITOBA. 



By D. B. Dowling, B. A. Sc. 



(By permission of the Direct; r cf the Geological Survey.) 



Along the western edge of the great Archaean area which lies north 

 and west of Lake Superior, stratified deposits are found lying uncon- 

 formably on the irregular surface of these older rocks. 



As early as 1819 they were recognized by Sir John Richardson, 

 who accompanied Sir John Franklin on his overland expedition, to be 

 similar in age to those of the Black River formation of eastern Canada. 

 Numerous papers have since been published on observations made in 

 other localities, and prominent among these is the report by Prof. H. 

 Y. Hinde, of the Saskatchewan Exploring Expedition. The general 

 conclusions from all these reports and papers is, that there is a definite 

 series found in the district, which represents the Hudson River forma- 

 tion, but the beds in the lower part of the section have become rather 

 confused, owing to a lack of definite knowledge as to their sequence. 



During the seasons of 1890 and 1 Sg r, Mr. J. B. Tyrrell, with the 

 writer as assistant, was engaged in a survey of the geological features of 

 Eastern Manitoba, having special reference to the exposures of the 

 rocks on the shore of Lake Winnipeg. A part of the writer's duties 

 consisted in making an examination of the exposures on the islands and 

 western shore of the lake, in order to follow as closely as possible, the 

 sequence of beds and determine the probable thickness and extent of 

 the formation. The present paper is intended to give in outline, the 

 field relations of the several exposures visited and examined by either 

 Mr. Tyrrell or the writer. A full detailed account will be found in the 

 forthcoming Report by Messrs, Tyrrell and Dowling in the Annual Re- 

 port of the Geological Survey Department. 



