95 

 SERPENTINES OE CANADA. 



By N. J. Giroux, F.G.S.A., C.E., P.L.S., of the Geological Survey of Canada. 



The study of serpentinous rocks and other serpentines is certainly 

 one of much interest and has been followed with great enthusiasm by 

 several of the most eminent geologists. 



As serpentines are met with in almost every country where geolo- 

 gical work has seriously been taken up, scientists of all schools took 

 part in the great discussions which ensued from their geognosy and 

 geogenv. Such being the case it mav be well to enunciate the views of 

 a few of the best known writers on the subject before describing the 

 mode of occurrence of our Canadian serpentines. The divergence of 

 opinion as to the mode of formation and occurrence of serpentine did 

 not originate until the view was expressed that they were of eruptive 

 origin, and this is not so very long ago. as the most distinguished 

 scientists were all of the opinion, at the beginning of this century that 

 serpentines were stratified contemporaneous deposits. In 1826, 

 Maculloch, in his geological classification of rocks, separated the primi- 

 tive rocks into two groups, stratified and unstratified, and placed the 

 serpentines and granites together in the latter. But subsequent studies 

 led him to announce that like gneiss or mica-schist, the serpentines are 

 stratified rocks. The great objection then, to classing serpentines with 

 the unstratified rocks was that • unlike granite and trap, they had not 

 been found to present dykes or ramifying veins. However, De la Beche, 

 Brongniart, Elie de Beaumont and many others regarded thorn as an 

 erupiive rock, and Professor Hitchcock, in 1835, speaking of serpen- 

 tine says : 



" Dr. Maculloch considers it as sometimes stratified ; and accord- 

 ingly enumerates it in both these classes and also as a veinous rock. 

 It occurs in connection with granite, gneiss, micaceous, chloritic and 

 argillaceous schists." 



These characters apply to the serpentine of Massachusetts, accord- 

 ing to Professor Hitchcock, who places it along with the limestones in 

 the stratified class. Favre and Stapff regard the serpentines as of 

 aqueous and sedimentary origin. Dr. T. Sterry Hunt in 1859 and 

 1860 speaking of these rocks said they were undoubtedly indigenous 



r 





