113 



extensively quarried for that purpose by the New Eockland Slate Co. 



This serpentine is not only well adapted for interior decorative 

 purposes but can also lie used for the manufacture of small articles such 

 as chandeliers, inkstands, paper weights, etc., etc. 



In France serpentine is used for the manufacture of sulphate of 

 magnesia or epsora salt. The magnesia which may easily be obtained 

 from this sulphate makes fine hydraulic cements particularly well fitted 

 for constructions exposed to the action of sea water. 



CARBONIFEROUS SERPENTINES. 



These constitute the last of group No. 2 or the palaeozoic serpen- 

 tines, and so far as we know, are of very limited extent. 



In the Geological Survey report for 1877-78, page 93 B, Dr. 

 Dawson speaking of the rocks of Cache Creek series, British Columbia, 

 says : 



" Whatever uncertainty might remain with regard to the region 

 now in question has been set at rest by the discovery of fusuline lime- 

 stone on the Bonaparte, interbedded with the siliceous and serpen tin- 

 ous rocks. The occurrence of seipentinc and other metamorphic rocks 

 of ancient appearance in beds of carboniferous age, is in itself a. point 

 of considerable interest. In the place above referred to, it is said tha t 

 " the limestones holding these fossils are so intimately associated and 

 interbedded with the serpentines and other crystalline rocks above 

 described, as to leave no doubt that they all belong to the same series." 

 This statement I have been able to confirm by the examination of 

 many additional localities. Between Hat Creek and 124 miles past 

 (Mundorf's) numerous exposures in the roadside show the intimate 

 association and interbedding of the cherty siliceous rucks with serpen- 

 tines pure and impure, and of the latter with volcanic breccias of green- 

 ish-grey colour." 



Of the serpentines of the Bonaparte River, Dr. Dawson reports as 

 follows : — 



" They may often be recognized at a distance by the bluish banks, 

 bare of vegetation, which they produce on weathering. Here the rela- 

 tion between the serpentine and other rocks was most clearly seen. . . 

 There can be little doubt that serpentines in this group of rocks have 

 been igneous materials of some sort, and perhaps owe their conversion 



