BY W. N. BENSON. 



531 



following both tlie Albite and Carlsbad laws. Zoning is common 

 in felspars, and chloritisation has just started among the biotites. 

 This latter specimen would be more correctly classed as a micro- 

 granite. The former is a true granophyre.^ 



The second occurrence of granophyres is in the railway line 



near 



the 163-J-mile 



peg. It is in the form of a long, nearly 

 horizontal vein of which about 80 yards are exposed in the 

 cutting. Should it be carefully traced, I believe it will be found 

 to extend for some distance, as specimens of a macroscopically 

 very similar rock occur nearly one mile to the south at George's 

 Plains Creek. It intrudes the slate very strongly, as may be 

 seen in Plate xxiii., fig. 4. A precise description of the rock is: — 



Macroscopical. — Fine-grained base, with small phenocrysts of 

 quartz and hexagonal biotite, and very large crystals of orthoclase 

 an inch or more long. 



Microscopical. — Large crystals of plagioclase almost idio- 

 morphic, and small allotriomorphic phenocrysts of orthoclase, 

 both with dusty inclusions; irregular grains of quartz also occur. 



Fig. 3. — Intergrowth of quartz (black) and felspar showing 

 Baveno twinning. Highly magnified. 



There is in my section one grey, hexagonal, isotropic section of 

 garnet. Small flakes of mica and grains of magnetite are present 

 also. In between all these crystals is a base of "panidiomorphic" 



* Teall, British Petrography, p. 292. 



