38 THE CANADIAN NATURALIST. [Marcll 



beds of a more calcareous nature, but, as Sir W. E. Logan 

 remarks, "few of tliem pure enough to be entitled to the 

 appellation of limestone." A specimen from a bed of this nature 

 yielded the following results : — 



Silicious matter 57 '3° 



Soluble in Acid — 



Protoxide of Iron 3 "45 



Alumina 2-36 



Carbonate of Lime i9'88 



Carbonate of Magnesia I'HS 



Soluble in Alkali — 



Silica 3 '44 



Carbonaceous matter and water (by difference) 2-12 



100 '00 



With the sandstones there are frequently interstratified shaly 

 layers, generally of a darker colour, which behave before the blow- 

 pipe like the sandstone above mentioned, but never shew the 

 slightest effervescence with acid. On analysis, a specimen gave : — 



Carbonaceous matter (loss on ignition) 2^04 



Silicious matter 65 ■ 7 1 



Soluble in Acid — 



Protoxide of Iron 7-20 



Alumina 8 • 58 



Magnesia o'43 



Soluble in dilute Potash ley— 



Silica II '56 



Alkalis, etc. (by difference) 4-48 



100 '00 



These sandstones and shales are, for the most part, very evenly 

 and regularly stratified, and only in the neighbourhood of the inter- 

 secting dykes are they at all contorted. In some places they 

 appear almost horizontal, but they generally shew a dip of from 

 3° to 6° to the east or south of east. Nothing resembling trans- 

 verse cleavage was found in these sandstones or shales, and, even 

 in the latter, the schistose structure, which is developed by 

 weathering, is more of a flaggy than of a slaty nature. The 

 vertical jointing, mentioned by Sir "VV. E. Logan, is visible at 

 almost every exposure of these sandstones and shales on the 

 location. In this respect, and in general lithological characters, 

 they much resemble the sandstones which occur to the north and 

 south of Point aux Mines, on the east shore of the lake, and 

 which, there, appear to overlie unconformably the traps and 

 conglomerates of Maimanse. 



Immediately and conformably overlying the sandstones and 



