177 



Simple ClassiRcaiion of JFelspar-learing Igneous Socks* 



3Iinerals charac- 

 teristically pre- 

 sent. 





Glassy 



og'^Cry. 





u -^ 



Crj's 





Free silica. 

 ACID. 



No free silica. 

 INTEEMEDIATE. 



Poor in silica, 

 BASIC. 



( 



Orthoclase Felspar. 



Plagioclase Felspar. 



pre--' 



Quartz. 



No Quartz. 



Hornblende. 



Pyroxene. 



Biotite, 



Olivine. 





Rhyolite Glass 

 (Obsidian, &c.) 



Trachyte Glass. 



Andesite Glass. 



Basalt Glass 

 (Tachylyte). 



letely 

 nine . 



Rhyolite, 

 Quartz-porphyry. 



Trachyte. 

 Many Felsites. 



Andesite. 



Basalt. 



etely 

 nine. 



Granite. 



Syenite. 



Diorite. 



Dolerite. 

 Gabbro. 



Typical Localities in New South Wales. 



Ehy elite Glass — Tweed Eiver ; Bulladelah. 



Ehyolite — Paddy's Hill (Raymond Terrace.) 



Quartz-porphyry — Burragorang, and many others. 



Grranite — New England Table-land. 



Trachyte — Canoblas (Orange). 



Andesite G-lass — Clarence Town. 



Andesite (Hornblende) — Carcoar. 



Andesite (Augite) — Port Kembla. 



Diorite — Cox Eiver. 



Basalt Glass — Inverell, Cndal. 



Basalt — Canoblas, Sydney, and. many others. 



Dolerite — Sydney. 



Gabbro — Nundle. 



*The recent discovery in the Snowy Eiver District, and rear Lite, of igneous rocks 

 characterised by the presence of nepheline, will necessitate an amplification of this table, 

 A few ultra-basic rocks will also have to be arranged for. 



