ITS ORIGIX. 101 



nnd veinstones ; and the phenomena of both would appear to exphiin tlie 

 mysteries hovering about the serpentine question. 



The writer has been unable to find anything in the published reports of 

 the Canada Geological Survey to substantiate the often repeated statement, 

 that this survey had proved, prior to 18-58, that the Canadian serpentines 

 were in stratified sedimentary deposits. The geologists of that survey appear 

 to have assumed, without proof, that the serpentines were so deposited, and 

 worked out their geology on that supposition. Then, finally forgetting the 

 basis on which the assumed stratification was placed, they afterwards declared 

 that they had proved these rocks to be stratified ; but the correctness of that 

 statement is not here allowed. And in this connection it may be said that 

 Dr. Hunt's " Geological History of the Serpentines " is looked upon here as 

 having the same inaccuracies that all his other papers have been found to 

 contain, when the present writer has had occasion to critically examine their 

 contained statements, both of fact and opinion (ante, p. 38).* 



The question now arises : Can serpentine result from the alteration of any 

 rock except the peridotites ? In the preceding pages it has been shown that 

 olivine is the chief producer of serpentine, but that in olivine rocks enstatite 

 and even diallage are changed to serpentine, although more slowly than the 

 olivine. It has also been shown that in the cumberlandite more or less 

 serpentine had been formed during the alteration of this olivine-magnetite 

 rock. So, too, it is well known to lithologists that the olivine of the basaltic 

 rocks is subject to alteration to serpentine, which, in the gabbros and other 

 old basalts, produces a rock imj^erfectly serpentinous. It would seem, then, 

 that any rock containing olivine or enstatite, may become more or less ser- 

 pentinized, although it would appear that, outside of the peridotites proper, 

 true serpentines that are not veinstones, rarely, if ever, occur. 



The reader is further referred, for the literature and general discussions 

 of the serpentine question by others, to Roth's " Ueber den Serpentin und 

 die genetischen Beziehungen desselben," f Riess's '' Ueber die Entstehung 

 des Serpentins," :|: and the lithological text-books of Rosenbusch and 

 Zirkel. 



The production of talcose rocks or talcose schists, as early advocated by 

 Genth {ante, p. 119) appears to be one of the results of the alteration of 



* See also " Azoic System," Bull. Mus. Coiup. Zool, 1SS4, vii. No. 11 ; and Bouuey, Geol. Mag., ISSl [o), 

 i. 406-412. 



t Abh. Berlin. Akad., 1869, ii. 329-361. 



t Zeit. Gessam. Natur. Berlin, 1879 (3), iv. 1-18. 



