64 B GEOLOGICAL SURVEY OF CANADA. 



&c. To Mr. Richardson's section it therefore becomes necessary to add 

 two lower members, which may be designated : — 



D. Agglomerates. 



E. Lower Sandstones. 



General condi- The letters applied to the subdivisions are my own — A., B. and C. 

 corresponding to 3, 2 and 1 of the original classification. 



The whole formation at this place bears the appearance of having 

 been laid down along the north-eastern flanks of a land formed chiefly 

 of the Triassic rocks previously described. It has a more or less 

 littoral character throughout, with irregularity in thickness of the sub- 

 divisions, and shows especially a very decided thinning out to the 

 southward and westward, in which directions it is probable that large 

 areas of the older rocks may have remained uncovered by those of the 

 coal-bearing group, and as may be supposed, their surface even where 

 it has been buried is a very rough and irregular one. This, com- 

 bined with the occurrence of the massive contemporaneous volcanic 

 deposit (D.) and the general disturbance of the rocks, — which increases 

 westwai'd till at the head of the inlet some of those of the coal-bearing 

 series are thrown past the vertical, — has produced a stratigraphical 

 problem of more complexity than would at first sight appear. 



Subdivi.-ion A. A. Upper Shales and Sandstones. — The highest rocks seen in Skide- 

 gate Inlet are these so-called by Mr. Richardson, and in character- 

 izing them I cannot do better than quote his description, which is as 

 follows. * 



" These shales are by no means so black as the lower band, their 

 darkest tint being a brownish or blackish grey, and most of them are 

 somewhat arenaceous. They are interstratified with sandstones, gene- 

 • rally from three to six inches thick ; but a band of about thirty feet 

 occupies a position which is conjectured to be about seventy feet from 

 the base. Approaching the (underlying) conglomerates, some twenty 

 or thirty feet are interstratified with beds of reddish-weathering 

 greyish-brown argillaceous dolomite, varying in thickness from two to 

 six inches, but constituting the chief part of the mass, and these seem 

 to form a passage to the conglomerates." 



Some beds of the shales are highly calcareous, and there are zones 

 characterized by lai-ge calcareous nodules like those of portions of the 

 Lower Shales, from which, notwithstanding their general difference in 

 colour, it would be hard to find a distinctive lithological characteristic. 

 The rocks of this subdivision occupy a breadth of three miles of the 

 inlet, between the west end of Lina Island and Slate Chuck Creek. 



* Report of Progress, 1872-3, p. 63. 



