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



and frequently surrounds this mineral. The felspar is difficult 

 of determination, but it seems to be sometimes oligoclase, some- 

 times andesine. The ilmenite is usually represented by titano- 

 morphite. Some sheared varieties of dolerite occur in which 

 saussuritised felspar alternates with streaks of tremolite. 



Granite. 



The granite has been described by Mr. Card as follows : — 

 "66G5. Moonbi, close to the railway station. Not conspicuously 

 porphyritic. Sphene readily visible. 'J he quartz is crowded 

 with cavities. Hornblende and magnetite are intimately asso- 

 ciated in places, and, together with felspar, give rise by segrega- 

 tion to basic patches. Orthoclase and plagioclase are present. 

 The plagioclase may contain many foreign inclusions, and may 

 show good composition zoning; it appears to be a variety of 

 oligoclase. Sphene is conspicuous, and shows some intergrowth 

 with hornblende. 



3728. Moonbi Tobacco Farm. This type is decidedly dioritic, 

 and differs much from that above described. It is non-porphy- 

 ritic. vSphene is abundant and can be readily obtained (some- 

 times in well formed crystals) by washing the crumbling material 

 under water. Under the microscope, one of the dominant 

 minerals is hornblende; biotite is scarce. The hornblende is 

 deep green in colour for the most part. It is more or less auto- 

 morphic, and well cleaved. Sphene is plentiful. There is a 

 little quartz, and practically no plagioclase. Orthoclase is 

 perhaps somewhat larger in quantity than the combined ferro- 

 magnesian silicates. The leucocratic constituents are plentifully 

 traversed by highly elongated, colourless, transparent rods. As 

 a handspecimen, this rock would be classed as a quartz-syenite." 

 (12). 



Sections examined by the writer show similar features to those 

 recorded above, but, in general, orthoclase does not seem to be 

 so abundant as there indicated. 



The numerous dykes of pegmatite and aplite have not been 

 subjected to microscopical examination. 



