298 



where unmetamorphosed are composed almost entirely 

 of calcium and magnesium carbonates, the former greatly 

 predominating. The only impurities are small amounts 

 of argillaceous and carbonaceous matter and pyrite. Near 

 the intrusive granitic rocks the Sutton limestones have 

 been contact metamorphosed into light coloured, coarsely 

 crystalline marbles carrying diopside and wollastonite, 

 and even into garnet-diopside-epidote rocks and silicified 

 and mineralized varieties. 



The following analysis is of a sample of limestone from 

 Rosebank Lime Company's quarry half a mile west of 

 Esquimalt harbour by F. G. Wait of the Department of 

 Mines. 



CaC0 3 95-35 



MgC0 3 2-85 



Fe 2 3 -f-Al 2 3 o-i6 



Insol i-95 



S tr. 



P tr. 



100-31 



The Sutton limestones and Vancouver volcanics are in 

 general contemporaneous and conformable, the limestones 

 probably having been built by marine organisms that 

 lived on the shores of volcanic islands formed during the 

 eruption of the Vancouver volcanics. However, the actual 

 contacts between the two formations are intrusive, the 

 volcanics cutting the limestones. The intrusive contacts, 

 which are also observed between the volcanic rocks them- 

 selves, do not indicate that the limestones are an older 

 formation or necessarily occur near the base of the Vancou- 

 ver volcanics, but merely indicate that intrusive volcanic 

 types occur intermingled with the limestones as well as 

 with one another. 



The Vancouver volcanics and Sutton limestones have been 

 greatly deformed, doubtless largely during the upper 

 Jurassic orogenic period. The general strike of the rocks, 

 which on account of their massive character were, for the 

 greater part, presumably warped into large folds, is about 

 N. 8o° W., and the dips are usually steep. The original 

 bedding of the rocks is almost completely obscured, but 

 the rocks are foliated, and the foliation and bedding appear 



