Centre Valley Tin Ore 



reveal the presence of any granite or other igneous rock 

 at the surface, but the occurrence of the metamorphic 

 rocks distinctly indicated the presence of such a rock at 

 no great depth. 



Nothing is known with certainty as to the way in 

 which the gold is introduced into veins of this type, but 

 its constant association with sulphides such as iron- 

 pyrites points to the two substances having been carried 

 simultaneously by the same agent. Very frequently the 

 iron-pyrites is impregnated with small quantities of gold, 

 and when it is remembered that gold is soluble in certain 

 alkaline sulphides the connection appears closer still. 



These quartz veins would certainly yield pay-ore, 

 but they would, of course, require the erection of stamps 

 for crushing the quartz before the gold could be ex- 

 tracted from it. It was, therefore, improbable that they 

 would be worked while the rich alluvial fields below 

 continued to yield. 



Several other quartz veins were encountered on our 

 way downstream between the group just described and 

 those which we had seen on our previous visit, but 

 none of them gave such good indications as those of the 

 group. 



On reaching the place where the rich deposits 

 mentioned on page 241 had been found, we at once 

 came across signs of habitation, and here we discovered 

 our old prospector who had left our employ on the 

 completion of the trial bore-holes near Lyell. 



He had come up country with many others who had 



staked claims near Three Forks. He was not satisfied 



with the prospects there, and so had struck out for 



himself and rediscovered the only claim in the country, 



T 289 



