36 Canadian Record of Science. 



> 

 ite, fergusonile, aeschynite, polykrase. xenotiine, mala- 

 konite, etc.). These veins, which in all their characteris- 

 tics correspond completely with the no less celebrated veins 

 of granitic pegmatite of Arendal, which occur in gneiss and 

 other crystalline schists, occur in a very basic rock, which 

 in its composition is very unlike that of the vein ; it is a 

 labradorite rock (in part anorthite). To that excellent 

 observer, Th. Scheerer, who, upon various grounds which 

 at present must appear of no moment (occurrence of quartz 

 in the vein3, nature of the so-called pyrognomic minerals, 

 etc.), declared against the eruptive origin of these veins, 

 this circumstance appeared of so much weight that, unwill- 

 ing as he then was to do so, he was obliged to assume that 

 the material of the veins must in some way have been trans- 

 ported thither : " I believe that we are obliged to consider the 

 granite as a mass in some way conveyed to the norite, when 

 we consider how great the difference is which exists be- 

 tween the two rocks. We have seen that the constituents 

 of the norite adjacent to the granite veins are labradorite, 

 a peculiar soda feldspar, and, in part, hypersthene and 

 titanic iron, while the mass of the granite consists mostly 

 of orthoclase, oligoclase and quartz," etc. 1 



The explanation of the exact correspondence of the nu- 

 merous granitic pegmatite veins of Hittero with those of 

 the environs of Arendal is simply this, that in both local- 

 ities they occur distributed along, although at a certain 

 distance from, the boundary of a granite district with which 

 they are genetically connected. 



In many other districts we notice that pegmatite veins 

 occur in rocks which, in their composition, do not at all cor- 

 respond to that of the veins. For instance, W. C. Kerr 

 mentions 2 that the well-known pegmatite veins of North 

 Carolina, so rich in minerals, occur in gneiss and mica 

 schist. A. de Lapparent 3 describes granitic pegmatite 



1 Gaea Norvegica, 1884, 2, 339. 



2 "The Mica Veins of North Carolina," Transactions of the Am. Inst, of 

 Mining Engineers, Feb., 1880. See Ref. in Neues. Jahrb., 1881, 2, 387. 



3 Note sur la pegmatite de Luchon," Bull. d. 1. soc. geol. de France, 1880, Ser. 

 I [I., 8. 



