156 ORIGIN AND MODE OF OCCURRENCE OF GOLD-BEARING VEINS. 



or vapours carrying their constituents in solution. The laminated 

 quartz veins and other auriferous lodes of Australasia give 

 numerous instances of this phenomena, and not only does the 

 quartz or other matrix have a laminated appearance, but the gold, 

 iron pyrites, and associated minerals occur continually in seams 

 parallel to the walls of the lode or vein, and between the layers of 

 quartz are often found very thin leaves of a kind of slate (mostly 

 chlorite slate). Flucans or slickensides sometimes exist between 

 the lodes and their walls. Amongst other instances, given in this 

 essay, of laminated lodes may be mentioned the Marshall McMahon 

 Reef at Murrumburrah, New South Wales, the Mount Morgan 

 lode in Queensland, the Catherine Reef at Clunes in Victoria, the 

 St. Patrick and Rainbow Reefs at Charter's Towers, Queensland, 

 and the Bassick lode in Colorado, United States ; this last being 

 a most remarkable instance of consecutive deposition of minerals, 

 and if we depart from auriferous lodes to those worked chiefly for 

 other metals or minerals the instances of laminated veins are 

 innumerable. 



In connection with this it will be well to refer to Mr. Wilkinson's 

 experiments on the deposition of gold from solution in the presence 

 of organic matter, and without quoting these experiments which 

 may be seen detailed in Locke's book, entitled " Gold," attention 

 should be called to the fact that they conclusively prove that gold 

 can be precipitated from solution in the presence of organic matter 

 by either pyrites, antimony, or several other minerals. 



It is of course well known that gold is present in sea water in 

 small quantities, and it must consequently be inferred that many 

 of the subterranean streams of water also carry gold in solution. 



Mr. Skey has stated that he obtained the same results as Mr. 

 Wilkinson, even when no organic matter was present in the 

 solution, and ascribed the action to the formation of a voltaic 

 pair between the pyrites and gold. Both these gentlemen have 

 applied their observations to account for nuggets in the alluvial 

 deposits, but the information given appears to me of much greater 

 value in accounting for the occurrence of gold in veins situated in 

 the internal laboratory of the earth. 



The Hot Springs of New Zealand which deposit silica as a 

 sinter, and the Steam Boat Springs in America which are gradually 

 filling up fissures with silica containing metals which are 

 precipitated from heated water in course of circulation, are instances 

 of what water can do in this respect. 



That the contents of lodes and veins are influenced by the rocks 

 containing them has not only been held by scientific men, but also 

 recognised as an axiom by the practical miner in his prospecting 

 and working of lodes and veins. 



