president's address. 573 



proved to be quartz reefs traversing Silurian, Devonian and 

 Carboniferous strata, as well as diorite, porphyry, serpentine 

 and granite. 



At Young, Araluen, and in some other gold fields, the 

 alluvial gold has evidently been derived not only from the quartz 

 reefs in the granite, but also from the granite itself; these 

 granites are always hornblendic. 



Thus the precious metal occurs in different formations, and it 

 is often associated with one or more of the following minerals- 

 iron pyrites, copper pyrites, galena, mispickel, stibnite, blende, 

 native arsenic, native bismuth, molybdenite, silver ores, 

 limonite, calcite, chlorite, muscovite, etc. Some of these show 

 that gold has been in solution in the meteoric waters at 

 various times. I have in my possession some stalactites 

 of limonite showing layers of gold in the concentric rings of the 

 iron ore. The abundance of the above-mentioned minerals, 

 especially the sulphides, in the quartz reefs renders the gold 

 somewhat difficult of extraction, and it is believed that when 

 less costly methods of treatment than those at present in use 

 are introduced, many reefs now lying idle will be profitably 

 worked. The deepest quartz mine in New South Wales is the 

 Great Victoria Mine at Adelong : the reef traverses metamorphic 

 granite and has been followed almost vertically to a depth of 1050 

 feet. Hydraulic sluicing appliances have been introduced 

 to work the extensive Tertiary drifts in the Kiandra mountains. 

 There are so many interesting features connected with the 

 occurrence of gold that to ' describe them would require more 

 space than I now have at my disposal. I must, therefore, pass 

 on to a brief notice of our other mineral resources. 



Tin. 



Tin mining is one of the established industries of New South 

 Wales. You may form an idea of its importance when I tell 

 you that the value of the annual production for 1882 amounted 

 to £842,131. The principal tin mines are in the Vegetable 

 Creek and Inverell * districts on the western slopes of New 

 England, but the ore has also been found on the eastern slopes 



