430 W. G. Foye — Nephelite Syenites of Ontario. 



the nephelite pegmatites, sodalite was the stable product of 

 crystallization. 



How these soda solutions were, introduced into the magma 

 is not definitely known. Nevertheless, it is reasonable to sup- 

 pose that the so-called pneumatolytic elements now associated 

 with the nephelite syenites were the effective means of trans- 

 portation. The minerals of the nephelite pegmatite of the 

 Gooderham laccolith are nephelite, albite, sodalite, scapolite, 

 apatite, calcite, titanite, and pyrrhotite. Chlorine is associated 



Fig. 7c 



Fig. 7c. Albite resorped by nephelite (x 48). 



Figs'. 7a, b, c. Microphotographs of the nephelite pegmatite from the 

 crescentic body near Tory Hill. 



with three of these minerals, carbon dioxide with one, phos- 

 phorus with one, and sulphur with one. These elements are 

 believed to have been active in producing the nephelite syen- 

 ites. 



The writer is firmly of the opinion that Professor Smyth is 

 correct and that many lines of evidence lead to the conclusion 

 that the nephelite and sodalite rocks are associated with the 

 pneumatolytic state of igneous activity and are produced by 

 gaseous transfer of their elements. 



Recently while studying the chemical composition of the 

 amphibolites of Haliburton County, which Adams and Barlow* 

 have shown were derived from limestone, it was impressed on 



*F. D. Adams and A. E. Barlow, Memoir No. 6, Canada Geol. Surv. 1910, 

 pp. 103-111 ; also F. D. Adams, Journ. of Geol., vol. xvii, p. 1-16, 1909. 



