228 PROCEEDINGS OF SECTION C. 



throughout the length and breadth of the colonies, some of them 

 being of the greatest importance and value. In the majority of 

 cases the silver-bearing lodes are associated with Silurian rocks 

 and granites, bvit frequently dyke rocks, such as felsites, play an 

 important part in their mode of occurrence. The silver occurs 

 chiefly associated with lead, as galena, or cerussite, but is also 

 found with fahlore, and occasionally with arsenical pyrites. The 

 silver industry may be considered to be yet in its infancy, but in 

 the future will, probably, develop into very large proportions. 

 Regarding those other minerals which have not been otherwise 

 classified, kauri gum has yielded the largest returns. Antimony, 

 manganese, and chromite, have also been raised in some quantities, 

 as well as cobalt and nickel. Iron ores exist, but can hardly be 

 worked for export for many years, and diamonds and other 

 precious stones have been found in large quantities, but mostly of 

 small size hitherto. Lastly, a valuable deposit of alunite has 

 been discovered, the stone occurring in unlimited quantities, and 

 alum is now in the market, which is being manufactured from it, 

 and which is fully equal in quality to the famous Roman alum. 



A perusal of these data impresses upon one's mind the fact, 

 that Australasia is an essentially mining country, A place where 

 all classes of ores are found, and one which afibrds every induce- 

 ment to further development of its resources. There is no doubt 

 that we have other sources of wealth, but, in my opinion, the 

 future of Australasia will be very largely dependent upon the 

 minerals raised, and the industries dependent upon them. There 

 is perhaps no part of the world where valuable ores are so evenly 

 distributed through the ground, for whether we go north or south, 

 we find mines working, their success depending greatly upon the 

 skill which is brought to bear upon the extraction of the minei^al, 

 and the treatment of the ore. 



Thursday, August 30. 

 The following papers were read : — 



l._ON THE AGE OF THE MESOZOIC ROCKS OF THE 

 LAKE EYRE BASIN. 



By Ralph Tate, F.G.S., F.L.S., Professor of Natural Science 

 in the University of Adelaide, South Australia. 



In South Australia until the year 1877, the existence of deposits 

 of Secondary age* had not been demonstrated, although Mr. F. 

 G. Waterhouse, in 1862, collected a few fossils at the Gregory, 

 AVelcome, and Beresf oi'd Springs, which I determined to be identical 



* Quart. Journ. Geol. Soc, 1877, xxxiii. p. 258 ; Trans. Roy, Soc. S. Aust., 1879, iii. 

 pp. 104 and 179. 



