602 



GREAT SERPENTINE-BELT OF NEW SOUTH WALES, V., 



1132. Labradorite-dolerite, Portion 110, Parisli of Nemingha. 



1130. Albitic Spilite, Portion 48, Parisli of Nemingha. 



1136. Quartz-keratophyre, Portion 175, Parish of Nemingha. 



A. Soda-granite-porphyry, Tayvallich, Argyllshire, Scotland(26). 



B. Typical volcanic tuff, Tamworth(9). 



C. Matrix of coarse volcanic agglomerate, Tamwortii(9). 



The discovery of calcic rocks in this area brings a feature into 

 the discussion of the origin of the albitic rocks in this area, which 

 was not present in the Nundle district ; and some of the Tamworth 

 rocks show the same microscopical features as those considered by 

 various authors to indicate the secondary nature of albite in rocks 

 of the spilitic suite, which features were not observable in the rocks 

 described previously(17). As investigations are now in progress 

 in the region between the Tamworth and Nundle districts, the fur- 

 ther discussion of this question will be postponed till it be finished.* 



* The writer has received, too late for consideration in the present 

 paper, Dr. Nils Sundius' work, which deals with this problem. Geologie 

 des Kirunagebiets. 4. Beitrage zur Geologie des siidlichen Teils des Kiru- 

 nagebiets. Vetenskapliga och Praktiska Undersokningar i Lappland. 

 Anordnade af Luossavaara-Kirunavaara Aktiebolag. (Scientific and Prac- 

 tical Researches in Lappland, arranged by the Luossavaara-Kiirunavaara 

 Aktiebolag.) Upsala, 1915, 



