PRESIDENT S ADDRESS SECTION C. 



211 



The following analysis was taken from a sample of Melbourne 

 basalt : — 



SiOo ... 

 AI2O3 

 FeiO" 

 FeO ... 

 MgO ... 

 CaO ... 

 Na„0 ... 

 K„0 . 

 H„0 + 

 H.,0- 

 CO2 ... 

 TiO„ ... 

 V.O, ... 

 MnO ... 

 Cl„ ... 

 NiO.Co.O. 

 SrO ... 



49-95 

 18 -.51 

 6-42 

 5-18 

 6-30 

 8-80 

 3 '2.5 

 0-68 

 0-70 



015 



V-^ 



Total 



100-00 



CONCLUSION. 



In this account of the Volcanic Rocks of Victoria it will be noted 

 that I have not discussed the general question of the origin of the 

 magmas from which the volcanic rocks were derived, nor the possible 

 causes which led to their reaching the surface. This might well 

 form matter for a later paper. Prof. David (62) has already made 

 an interesting contribution to this vexed question. The above account 

 indicates that our present knowledge of the distribution, composition, 

 and varieties of the Victorian volcanic rocks is far from completei, 

 and in particular the Snowy River porphyries and the basaltic rocks 

 present abundant opportunities for further and extended petrological 

 aind chemical investisfations. 



BIBLIOGRAPHY. 



The following list of references comprises most of the papers 

 dealing wholly or in part with the Volcanic Rocks of Victoria, and 

 it is hoped that all the important and original contributions are 

 included. 



The references are arranged chronologically under each geological 

 period. 



